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Many already know that I feed weakness to all kinds of power supplies, here is two in one. This time there will be an overview of the radio constructor, which allows you to collect the basis for the laboratory power supply unit and the option of its real implementation.
I warn you, there will be many photos and text, so reserve coffee :)
For a start, I will explain a little what it is and why.
Almost all radio amateurs use such a thing in their work as a laboratory power supply. Whether it is complicated with software control or very simple on LM317, but it still performs almost the same thing, nourishes different loads in the process of working with them.
Laboratory power supplies are divided into three main types.
With impulse stabilization.
With linear stabilization
Hybrid.
The first to have a pulse controlled power supply unit in their composition, or simply a pulse power supply with a downgraded PWM converter. I have already overlooked several variants of these power supplies. .
Advantages - high power with small dimensions, excellent efficiency.
Disadvantages - RF ripples, the presence of capacious capacitors at the output
The second does not have any PWM transducers aboard, all adjustment is carried out by a linear way, where the excess energy is simply dispersed on the adjusting element.
Pluses are almost complete absence of pulsations, there is no need for condensers at the exit (almost).
Cons - efficiency, mass, envelope.
Third are the combination of either the first type with the second, then the linear stabilizer is powered by the slave-lowering of the transducer (the voltage at the PWM of the converter is always supported at a level slightly higher than the output, the rest is regulated by the transistor operating in linear mode.
Either this is a linear BP, but the transformer has several windings that switched as needed, thereby reducing the losses on the adjusting element.
The minus this scheme is only one, complexity, it is higher than that of the first two options.
Today we will talk about the second form of power supplies, with a regulating element operating in linear mode. But consider this power supply on the example of the designer, it seems to me that it should be even more interesting. After all, in my opinion this is a good start for a novice radio amateur, collect yourself one of the main appliances.
Well, or as they say, right block Nutrition should be heavy :)
This review is more focused on beginners, experienced comrades are unlikely to find something useful in it.
I ordered a constructor for review, which allows you to assemble the main part of the laboratory power supply unit.
The main characteristics are such (from the stated shop):
Input voltage - 24 volts of alternating current
The output voltage is adjustable - 0-30 volts of DC.
Output current adjustable - 2ma - 3a
Pulsation output voltage - 0.01%
Printing size - 80x80mm.
A little about packaging.
The designer came in the usual polyethylene package, closed into a soft material.
Inside in an antistatic package with a latch, all the necessary components lay, including a printed circuit board. 
Inside everything was a mound, but at the same time did not suffer printed circuit board Partially protected the radio components. 
I will not list everything that is included, it's easier to do it later along the review, I will just say that I just had enough, even something left. 
A little about the printed circuit board.
The quality is excellent, the scheme in the kit does not go, but all the rates on the board are indicated.
The board is double-sided, covered with a protective mask. 
Coverage of fees, tinning, and the quality of the textolite is excellent.
I got only in one place to tear the patch with the print, and then after I tried to have a non-rigid detail (why, it will be further).
In my opinion the most that for a novice amateur, spoil will be hard. 
Before installation, I figured the diagram of this sides. 
The scheme is quite thoughtful, although not without flaws, but will tell about them in the process.
The scheme looks through several main nodes, I separated them by color.
Green - adjustment knot and stabilization
Red - adjustment knot and current stabilization
Violet - node indicating the transition to current stabilization mode
Blue - source of reference voltage.
Separately there:
1. Input diode bridge and filter capacitor
2. Silence control unit on VT1 and VT2 transistors.
3. Protection on the transistor VT3, turning off the output until the power amplifiers are normal
4. Fan power stabilizer, built on a 7824 microcircuit.
5. R16, R19, C6, C7, VD3, VD4, VD5, a node for forming a negative power supply pole of operating amplifiers. Due to the presence of this node, the BP will not work simply from DC, it is necessary that the AC input from the transformer is necessary.
6. C9 output capacitor, VD9, output protective diode. 
First, silent the advantages and disadvantages of the circuit solution.
Pros -
Pleases the presence of a stabilizer to power the fan, but the fan is needed for 24 volts.
Very pleases the presence of a power source of negative polarity, it greatly improves the operation of BP on currents and stresses close to zero.
In view of the presence of a negative polarity source in the circuit, protection has been protected, until this voltage, the BP output will be disconnected.
BP contains a source of a support voltage 5.1 volt, this allowed not only correctly adjusting the output voltage and current (with such a scheme, the voltage and current are adjusted from zero to a maximum of linearly, without "humps" and "failures" in extreme values), and allows you to manage Power supply from the outside, simply changing the control voltage.
The output capacitor is a very small container, which allows you to safely check the LEDs, there will be no current throw until the output capacitor is discharged and the BP will not enter the current stabilization mode.
The output diode is necessary to protect BP from feeding the reverse polarity voltage to its output. True diode is too weak, it is better to replace to another.
Minuses.
The current-measuring shunt has too high resistance, because of this, when operating with a load current, 3 amps is released about 4.5 watt heat. The resistor is designed for 5 watts, but heating is very large.
The input diode bridge is dialed out of 3 amp diodes. According to good, there should be diodes at least 5 amps, since the current through diodes in such a scheme is 1.4 from the weekend, respectively, in the operation of the current through them there may be 4.2 amps, and the diodes themselves are calculated for 3 amps. It makes it easier for the situation that pairs of diodes in the bridge work alternately, but still it is not entirely correct.
Large minus is that Chinese engineers, when selecting operating amplifiers, chose OU with a maximum voltage of 36 volts, but did not think that the diagram was the source of the negative voltage and the input voltage in this version is limited at 31 volts (36-5 \u003d 31 ). With input 24 volts of alternating current, the constant will be about 32-33 volts.
Those. OU will work in the exhaust mode (36 is maximum, regular 30).
I will also talk about the pros and cons, as well as about modernization later, and now I will go to the assembly itself.
To begin with, lay out everything that is included. This will facilitate the assembly, and it will simply be clearly seen that they have already installed, and what else remains. 
I recommend starting an assembly from the lowest elements, as if you first set high, then the low then it will be inconvenient to put.
It is also better to start with the installation of those components that are more identical.
I will start with resistors, and it will be resistors with a par 10 com.
Resistors are qualitative and have accuracy of 1%.
A few words about resistors. Resistors have color labeling. This may seem uncomfortable. In fact, it is better than diguristic labeling, since the marking is visible in any position of the resistor.
It is not necessary to scare the color marking, at the initial stage you can use, and eventually it will be possible to determine it already without it.
For understanding I. convenient work With such components, you only need to remember two things that the novice radio amateur will be useful in life.
1. Ten basic marking colors
2. Nominal ratios, they will not be much useful when working with accurate resistors of the E48 and E96 resistors, but such resistors are much less common.
Any radio amateur with experience lists them simply by memory.
1, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2, 2.2, 2.4, 2.7, 3, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1.
All other denominations are multiplying these 10, 100, etc. For example, 22k, 360k, 39.
What gives this information?
And it gives that if a resistor of a series of E24, then for example, a combination of colors -
Blue + green + yellow in it is impossible.
Blue - 6.
Green - 5.
Yellow - x10000.
those. According to the calculations, there are 650K, but there is no such nominal in series of E24, there are either 620 or 680, it means that either the color is not recognized, or the color is changed, or the resistor is not a series of E24, but the latter is rare.
Well, enough theory, let's go further.
The conclusions of the resistors before installing I form, usually using a tweezers, but some use a small homemade device for this.
Cutting outputs are not in a rush, it happens that they can come in handy for jumpers. 
By installing the main amount I reached single resistors.
It may be harder here, it will be more often. 
I don't immediately solder the components, but I just bite and bend the conclusions, and we first webly, and then bend.
It is done very easily, the board holds in the left hand (if you are right-hand), the installed component is pressed at the same time.
In the right hand, there are side handers, we bite the conclusions (sometimes even several components at once), and the side of the side of the windings immediately bend the conclusions.
It all is done very quickly, after a while already on automation. 
So they reached the last small resistor, the nominal value of the required and what remains coincides, is not bad :) 
By installing resistors proceed to diodes and stabilion.
Small diodes here are four, these are popular 4148, Stabilians two at 5.1 Volta each, so it's very difficult to get confused.
They also formulate conclusions. 
The cathode is marked with a strip, as well as on diodes and stabilods. 
At least a fee and has a protective mask, but I still recommend bending the conclusions so that they do not fall on nearby walkways, in the photo the withdrawal of the diode will benthered away from the track. 
Stabilians on the board are also marked as marking on them - 5V1. 
Ceramic capacitors in the scheme are not very much, but their marking can confuse a novice radio amateur. By the way, it also obeys the number of E24.
The first two digits - nominal in picofarades.
The third digit is the number of zeros to add to the nominal
Those. for example 331 \u003d 330pf
101 - 100pf
104 - 100000 PF or 100 NF or 0.1MKF
224 - 220000PF or 220NF or 0.22MKF 
The bulk of passive elements is established. 
After that, go to the installation of operating amplifiers.
I guess I would recommend buying panels to them, but I fell as it is.
On the board, as well as on the chip itself, the first conclusion is marked.
The remaining conclusions are considered counterclockwise.
The photo shows a place for an operational amplifier and how it should be put. 
In the chips, I'm not all conclusions, but only a couple, usually this is the extreme conclusions on the diagonal.
Well, it is better to bite them so that they stick to about 1mm above the board. 
Everything, now you can go to the soldering.
I use the most ordinary soldering iron with temperature control, but quite enough and the usual soldering iron with a capacity of about 25-30 watts.
Solder diameter 1mm with flux. I specifically I do not specify the solder brand, since on the coil of a non-rigid solder (the native coils 1kg weighing), and the name of it is not familiar to him. 
As I wrote above, the board is high-quality, it rolls very easily, no fluxes I applied, enough only what is in the solder, you just need to not forget sometimes shaking an extra flux with sting. 
Here I made a photo with an example of a good soldering and not very.
A good soldering should look like a small droplet enveloping output.
But in the photo there are a couple of places where the solder is clearly not enough. This will be held on a double-sided platter with metallization (there the solder is also in the hole in the hole), but it cannot be done on a one-sided board, with time such a soldering can "fall off". 
Transistor's conclusions should also be previously defined, it is necessary to do this so that the output is not deformed near the base of the body (Aksakala will recall the legendary CT315, which believed the conclusions to be laid out).
Powerful components I form a little different. Molding is made so that the component stood over the board, in this case the heat will be less transmitted and it will not destroy it. 
This looks the molded powerful resistors on the board.
All components soldered only from the bottom, the solder that you see on the top of the board penetrated through the hole due to the capillary effect. It is advisable to solder so that the solder penetrates a little on the upper part, it will increase the reliability of the soldering, and in the case of heavy components, their better stability. 
If before this conclusions of the components, I molded with a pincelet, then small pliers with narrow sponges will already be needed for diodes.
Form conclusions as well as the resistors. 
But when installing there are differences.
If the components with subtle conclusions first take place, then bite, then the diodes are the opposite. You simply do not drive such a conclusion after biting, therefore, we first begin the conclusion, then we are biting superfluous. 
The power node is assembled using two transistors included according to the Darlington scheme.
One of the transistors is installed on a small radiator, better through the thermal paste.
In the kit there were four screw M3, one goes here. 
Couple photo of almost soldered board. I will not paint the terminal workers and other components, it is intuitive, and it can be seen by photography.
By the way, about the terminalnikov, the board has terminal blocks to connect the input, output, fan power supply. 
I have not yet rinsed the fee, although I often do it at this stage.
It is due to the fact that there will be another small part of the revision. 
After the main assembly stage, we left the following components.
Powerful transistor
Two variables of the resistor
Two connectors for installation on the fee
Two connectors with wires, by the way, the wires are very soft, but a small cross section.
Three coils. 
Initially, the manufacturer conceived to place variable resistors on the board itself, but so they are as inconvenient that I did not even solder them and showed just for example.
They cost very close and regulate will be extremely uncomfortable, although really. 
But thanks for not forgotten to give a wire with connectors, it is much more convenient.
In such a form, the resistors can be taken to the front panel of the device, and install the fee in a convenient location.
Along the way spared a powerful transistor. This is an ordinary bipolar transistor, but having a maximum scattered power up to 100 watts (naturally when installed on the radiator).
There are three screws left, I did not understand where to even apply them if at the corners of the board, then you need four if you fix a powerful transistor, then they are short, in general a riddle. 
You can feed the board from any transformer with output voltage up to 22 volts (in the characteristics stated 24, but I explained the above why this voltage cannot be applied).
I decided to use a long-lying transformer for a romance amplifier. Why for, not from, but because he has not yet stood anywhere :)
This transformer has two second-volt power windings, two auxiliary 16 volts and shielding winding.
The voltage is indicated for the input 220, but since we now have a standard 230, then the output voltages will be slightly higher.
The calculated transformer power is about 100 watts.
Weekend power windings I rang up to get more current. You could certainly use a straightening scheme with two diodes, but it will not be better with her, therefore left as it is. 
For those who do not know how to determine the power of the transformer, I took off a small video.
First trial inclusion. On the transistor, I installed a small radiator, but even in this form it was quite large heating, since the BP is linear.
Current and voltage adjustment occurs without problems, everything has earned immediately, because I have already completely recommended this constructor.
The first photo is the stabilization of the voltage, the second current. 
For a start, I checked that it issues a transformer after straightening, as this determines the maximum output voltage.
I got about 25 volts, not thick. The capacity of the filter capacitor is 3300MKF, I would advise it to increase it, but even in this form, the device is perfectly operational. 
Since it was necessary to apply a normal radiator for further check, then I switched to the assembly of a future design, since the radiator installation depended on the planned constructive.
I decided to apply IGLOO7200 lying radiator. According to the manufacturer's application, such a radiator is able to disperse up to 90 watts heat. 
The device will be used the Z2A case in theory of Polish production, the price of about 3 dollars. 
Initially, I wanted to move away from the chassis came from my readers, in which I collect all sorts of electronic things.
To do this, I chose a slightly smaller body and bought a fan with a mesh to it, but I did not turn into it all the filling and the second case was purchased and the second fan, respectively.
In both cases, I bought Sunon fans, I really like the products of this company, also in both cases bought fans for 24 volts. 
So, on the idea, I had to install a radiator, a board and a transformer. There is even a little space on the expansion of the filling.
Turn the fan inside did not work in any way, because it was decided to place it outside. 
Place the mounting holes, cut the thread, screw it for fitting. 
Since the selected case has an internal height of 80mm, and the board also has such a size, then I secured the radiator so that the fee is obtained symmetrically with respect to the radiator. 
The conclusions of the powerful transistor also need to be modified slightly so that they are not deformed when the transistor is pressed to the radiator. 
A slight retreat.
The manufacturer for some reason was conceived a place to install a rather small radiator, because of this, when setting a normal, it turns out that the fan power stabilizer and the connector will interfere with it.
I had to fall out, and the place where they were, stuck with scotch, so that there was no connection with the radiator, since there is a voltage. 
I cut extra tape from the opposite side, otherwise it turned out as it was completely inaccurarately, we will do on the flush :) 
This looks like a printed circuit board with a finally installed radiator, the transistor is installed through the thermal colon, and it is better to apply good thermal plaistersince the transistor dispels the power comparable to powerful processor. about 90 watts.
At the same time, I immediately made a hole for installing the fan speed regulator board, which eventually had to reap :) 
To set the zero and unscrewed both regulators to the leftmost position, turned off the load and set the zero at the output. Now the output voltage will be adjusted from zero. 
Further a few tests.
I checked the accuracy of maintaining the output voltage.
Idling, voltage 10.00 volts
1. Load current 1 amp, voltage 10.00 volts
2. Load current 2 amps, voltage 9.99 volts
3. Load current 3 amps, voltage 9.98 volts.
4. Load current 3.97 amps, voltage 9.97 volts.
The characteristics are quite good, if you wish, you can still improve them by changing the connection point of resistors. feedback By voltage, but as for me, enough and so. 
I also checked the level of ripples, the check took place at a current of 3 amps and 10 volts output voltage 
The level of ripples amounted to about 15mB, which is very good, though thought that in fact the pulsation shown in the screenshot was rather diagnosed from an electron load than from the BP itself. 
After that, I started assembling the device itself as a whole.
Started from installing a radiator with a power supply board.
To do this, I placed the installation site of the fan and power connector.
The hole was not completely round, with small "cuts" at the top and below, they are needed to increase the strength of the rear panel after cutting the hole.
The greatest complexity usually represent the holes of a complex form, for example, under the power connector. 
A large hole is cut out of a big pile of small :)
The drill + drill with a diameter of 1mm sometimes creature wonders.
Drills holes, many holes. It may seem that it is long and tedious. No, on the contrary, it is very fast, the complete drilling of the panel takes about 3 minutes. 
After that, I usually put the drill slightly more, for example, 1.2-1.3mm and I pass as a cutter, it turns out such a break: 
After that, we in the hands of a small knife and cleaned the resulting holes, at the same time cut a little plastic if the hole was slightly smaller. Plastic is quite mild, therefore it is convenient to work. 
The last step of preparation drills the fastenings, we can say that the main work on the back panel is over. 
We establish a radiator with a board and a fan, trying on the resulting result, if necessary, "we refund with a file". 
Almost at the very beginning I mentioned refinement.
I will refine a little.
For a start, I decided to replace my native diodes in the input diode bridge on Schottky diodes, I bought four pieces 31dq06 for this. And then I repeated the error of the developers of the board, buying diodes on the inertia to the same current, and it was necessary for a greater. But still the heating of the diodes will be less, since the fall on Schottky diodes is less than on the usual.
In second place, I decided to replace the shunt. I was not satisfied not only that it was heated as an iron, but the fact that it falls about 1.5 volts, which can be used in the case (in the sense of the load). To do this, I took two domestic resistors 0.27 1% (it will also improve stability). Why did not make the developers, it is not clear, the price of solving is absolutely the same as in the variant with the native resistor at 0.47 Ohm.
Well, rather as an addition I decided to replace the native capacitor of the filter 3300MKF better and capacious Capxon 10000 μF ... 
This is how the resulting design with replaced components and the installed fan thermocontrol board is.
It turned out a bit of collective farm, and besides, I accidentally threw one patch on the board when installing powerful resistors. In general, it was possible to calmly apply less powerful resistors, for example, one resistor for 2 watts, I just did not have this in stock. 
Low components were also added below.
Resistor by 3.9K, parallel to the extreme connector contacts to connect the current adjustment resistor. It is needed to reduce the voltage of adjustment as the voltage at the shunt is now different.
A pair of capacitors by 0.22mkf, one in parallel to output from the current adjustment resistor, to reduce the tip, the second simply on the output of the power supply, it is not particularly needed, I just accidentally took out a couple immediately and decided to apply both. 
The entire power part is connected to the transformer along the way, a board with a diode bridge and a capacitor to power the voltage indicator is installed.
By and large, this fee is optional in the current version, but to feed the indicator from the limit 30 volts for it. My hand did not rose and I decided to use an additional 16 volt winding. 
The following components were used to organize the front panel:
Terms for connecting the load
A pair of metallic handles
Power switch
Red Light Filter, declared as a light filter for KM35 enclosures
To indicate the current and voltage, I decided to use the fee left after writing one of the reviews. But I was not satisfied with small indicators and therefore were bought larger with a number 14mm, and a printed circuit board was made to them.
In general, this decision is temporary, but I wanted to even temporarily make carefully. 
Multiple stages of front panel preparation.
1. Blacksmith in front of the front panel of the front panel (I use the usual lyaout sprint). The advantage of applying the same buildings is that to prepare new panel It is very simple, since the necessary dimensions are already known.
We apply the printout to the front panel and in the corners of square / rectangular holes drills the marking holes with a diameter of 1mm. The same drill chop the centers of the rest of the holes.
2. According to the resulting holes, place the place of cut. We change the tool for a thin disc mill.
3. Slap straight lines, in front of it is clearly in size, the back is slightly more, so that the rubber was the most complete as possible.
4. We take out the cut slices of plastics. I usually do not throw them away, as they can still come in handy. 
Similar to the preparation of the rear panel process the resulting holes with a knife.
I recommend drilling a large diameter, it does not "eat" plastics. 
We try what we did, if necessary, we refirm with the help of the noer.
I had to slightly expand the hole for the circuit breaker. 
As I wrote above, for the indication I decided to use the fee left from one of the past reviews. In general, this is a very bad solution, but for a temporary option more than a suitable, I will later explain why.
We drag out the indicators and connectors from the board, the old indicators and new ones are ringing.
I painted the Codoolevka of both indicators so as not to get confused.
In the native version four-digit indicators were applied, I applied three-bit. Since I did not have any more in the window. But since the fourth discharge is needed only to display the letter A or U, then their loss is not critical.
LED Display Limit Mode I placed between indicators. 
I prepare everything you need, with an old board I drop out a resistor on 50mom, which will be used as before, as a toko-measuring shunt.
Here is a problem with this shunt and is associated. The fact is that in this version, I will have a voltage drop at a 50mw output for each 1 ampere of the current current.
You can get rid of this problem in two ways, apply two separate meters, for current and voltage, while drinking a voltmeter from a separate power source.
The second way is to establish a shunt in the positive Pole of BP. Both options were not suitable for a temporary solution, so I decided to step on my own perfectionism and make a simplified version, but far from the best. 
For the design, I used the mounting racks remaining from the DC-DC converter board.
I got a very comfortable design with them, the indicator board is attached to the ampervoltmeter board, which in turn is attached to the board of power terminals.
It turned out even better than I expected :)
Also on the board of the power terminals, I placed a toko-measuring shunt. 
The resulting design of the front panel. 
And then I remembered that I forgot to establish a more powerful protective diode. I had to dope it later. I used the diode left after replacing diodes in the input bridge of the board.
Of course, for a good need to add a fuse, but this is not in this version. 
But the current and voltage adjustment resistors I decided to put better than those that offered the manufacturer.
Natives are quite high-quality, and have a smooth move, but these are ordinary resistors and as for me a laboratory power supply must be able to more accurately adjust the output voltage and current.
Even when I thought to order a BP fee, I saw in the store and ordered a review and them, especially since they had the same nominal. 
In general, I usually apply other resistors for such purposes, they combine two resistor at once, for coarse and smooth adjustment, but lately I can not find them on sale.
Can someone know their imported analogues? 
Resistors are quite high-quality, angle of rotation of 3600 degrees, or by simple - 10 full revolutions, which ensures the rearrangement of 3 volts or 0.3 amps by 1 turnover.
With such resistors, adjustment accuracy is approximately 11 times more accurate than normal. 
New resistors in comparison with relatives, the envelope is certainly impressive.
Along the way, I have a little rooted wire to resistors, it should improve noise immunity. 
She packed everything into the case, in principle there was even a little place left, there is where to grow :) 
I connected the shielding winding with the grounding conductor connector, board additional nutrition Located right on the terminals of the transformer, it is certainly not very neat, but I have not yet invented another option. 
Check after assembly. It all started almost the first time, I accidentally confused two discharge on the indicator and could not understand that it was not so adjustable, after switching everything became as it should. 
The last stage is the inclination of the light filter, the installation of the handles and the assembly of the case.
The light filter has a thinning around the perimeter, the main part is interinted into the window window, and a more subtle part is glued with double-sided tape.
The handles were initially calculated under the diameter of the shaft of 6.3mm (if not confused), new resistors have thinner, it was necessary to wear a pair of layers of heat shrink.
The front panel I decided not yet to make it no matter and there are two reasons:
1. The management is so intuitive that there is no particular sense in inscriptions.
2. I plan to refine this power supply, because changes are possible in the front panel design. 
Couple photo of the resulting design.
Front view: 
Back view.
Attentive readers probably noticed that the fan is so that blows hot air from the housing, and does not pump cold between the risaries.
I decided to do so because the radiator is a little less than a case, and that hot air does not get inside, I put the fan on the contrary. This of course, noticeably reduces the efficiency of heat removal, but allows you to slightly ventilate and the space inside the BP.
Additionally, I would recommend to make several holes from the bottom of the lower half of the hull, but it is rather an addition. 
After all alterations, I turned out to be a little less than in the original version, and amounted to about 3.35 amps. 
And so, I will try to spite the advantages and cons of this board.
pros
Excellent manufacturer quality.
Almost proper circuitry of the device.
Full set of details for assembling power supply stabilizer board
Well suits novice radio amateurs.
In minimal form, only a transformer and radiator also requires, in a more expanded ampervoltmeter.
Fully workable after assembly, albeit with some nuances.
The absence of capacious capacitors at the output of BP is safe when checking LEDs, etc.
Minuses
The type of operating amplifiers is incorrectly selected, due to this, the input voltage range must be limited to 22 volts.
Not very suitable summary of the current measurement resistor. It works in a normal thermal mode for him, but it is better to replace it, as heating is very large and can harm the surrounding components.
The input diode bridge operates at a maximum, it is better to replace diodes to more powerful
My opinion. In the process of assembly, I had the impression that the scheme was developed two different people, one applied the correct control principle, the source of the reference voltage, the source of the negative polarity, protection. The second incorrectly chosen the shunt, operational amplifiers and the diode bridge under this.
I really liked the scheme engineering, but I first wanted to replace the operational amplifiers at first, I even bought microcircuits with a maximum working voltage of 40 volts, but then changed my mind. But the rest of the decision is quite correct, the adjustment is smooth and linear. The heating of course is, without him anywhere. In general, as for me, for a novice radio amateur, this is a very good and useful designer.
Surely there will be people who will write what is easier to buy ready, but I think that it is most likely to collect and more interesting (probably the most important thing) and more useful. In addition, many are quite calmly at home there is a transformer and radiator from the old processor, and some kind of box.
Already in the process of writing a review, I had even more feeling that this review would be the beginning in a series of reviews dedicated to the linear power supply, there are thoughts on refinement -
1. Transfer the indication and control circuit into a digital variant, possibly connecting to a computer
2. Replacing the operational amplifiers to high-voltage (I do not know what)
3. After replacing OU, I want to make two automatically switchable steps and expand the output voltage range.
4. Change the principle of measuring the current in the indication device so that there is no voltage drawdown under load.
5. Add the ability to disconnect the output voltage with the button.
That's probably all. Perhaps I still remember something and supplement, but I'm waiting for comments with questions.
Also in the plans to devote a few more reviews to designers for beginner radio amateurs, maybe someone will have suggestions about certain designers.
Not for the faint of heart
At first I did not want to show, but then I decided to make a photo yet.
On the left of the power supply that I enjoyed many years before.
This is a simple linear BP with a 1-1.2 amper exit at a voltage of up to 25 volts.
Here I wanted to replace it with something more powerful and correct. 
The goods are provided for writing a survey shop. The review is published in accordance with paragraph 18 of the site rules.
I plan to buy +249. Add to favorites I liked the review +160 +378This article is intended for people who can quickly distinguish the transistor from the diode, know what the soldering iron is needed and for which way it is to keep it, and finally reached the understanding that without a laboratory power supply, their lives no longer makes sense without a laboratory power supply ...
This scheme was sent to us under Nickname: lougin.
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Here I will try as much as possible - step by step to tell how to do it with minimal cost. Surely everyone after household upgrades is lying under their feet at least one BP. Of course, something will have to buy, but these victims will be small and most likely justified by the end result - this is usually about 22V and 14a ceiling. Personally, I invested at $ 10. Of course, if you collect everything from the "zero" position, then you need to be ready to post about $ 10-15 for the purchase of BP itself, wires, potentiometers, handles and other scatters. But, usually, such a trash has all in bulk. There is still a nuance - a little will have to work hard, so they must be "without offset" J and something like that can and you turn out:
To begin with, it is necessary for any ways to get unnecessary but serviceable BP ATH power\u003e 250W. One of the most popular schemes is Power Master FA-5-2:
A detailed sequence of actions I will describe for this scheme, but they are all valid for other options.
So, at the first stage you need to prepare a BP donor:
- We remove the diode D29 (you can simply raise one leg)
- We remove the jumper J13, we find in the diagram and on the board (bodging)
- Jumper PS ON to earth should stand.
- Turn on the PB only for a short time, as the voltage at the inputs will be the maximum (approximately 20-24V) actually this and want to see ...
Do not forget about the weekend electrolytes, calculated on 16V. Maybe they warm up slightly. Considering that they are most likely "swelling", they still have to be sent to the swamp, not sorry. Remove the wires, they interfere, and only GND will be used and + 12V then they solder them.
5. We remove 3.3x volt part: R32, Q5, R35, R34, IC2, C22, C21:
6. We remove 5B: assembling Schottky HS2, C17, C18, R28, can and "type choke" L5
7. Remove -12B -5B: D13-D16, D17, C20, R30, C19, R29
8. Change bad: replace C11, C12 (preferably on large capacity C11 - 1000UF, C12 - 470UF)
9. We change the inappropriate components: C16 (preferably on 3300uf x 35V as I have, well, at least 2200uf x 35v required!) And the resistor R27 advise it to replace it with a more powerful, such as 2W and resistance to take 360-560 Ohm.
We look at my fee and repeat:
10. We remove everything from the legs TL494 1,2,3 To do this, we remove the resistors: R49-51 (we release the first leg), R52-54 (... 2nd leg), C26, J11 (... 3D foot)
11. I do not know why, but R38 I have been dreamed by someone J recommended to reflub it. It participates in the feedback on voltage and stands in parallel R37. Actually, R37 can also be refunded.
12. Separate the 15th and 16th of the legs of the chip from the "all others": for this we make 3 cuts of existing tracks and to the 14th leg restore the link with a black jumper, as shown in my photo.
13. Now we swell the loop for the regulator board on the point according to the scheme, I used the holes from the dropped resistors, but to 14th and 15th I had to construct the varnish and drill holes, on the photo at the top.
14. Halling №7 lived (regulator nutrition) can be taken from meals + 17V Tl-ki, in the area of \u200b\u200bthe jumper, more precisely from it J10. Drill a hole in the track, clear the lacquer and there! Drill better from the press.
It was all, as the saying goes: "Minimum refinement" in order to save time. If the time is not critical, you can simply bring the diagram to the following state:
I would also advise you to change the corders of high-voltage at the entrance (C1, C2) they are a small container and certainly dried well. There normally become 680uf x 200V. Plus, the L3 group stabilization choke is not bad, or use 5 volt windings, connecting them in series, or to remove everything and wind about 30 turns with a new enamel shared cross section of 3-4mm 2.
To power the fan, you need to "prepare" to him 12V. I twisted in this way: where I used to stand the field transistor for the formation of 3.3V, you can "settle" 12 volt roll-ku (roll8b or 7812 imported analogue). Of course there is no cutting tracks and additives can not do. Ultimately, it turned out in general even "nothing":
In the photo it can be seen how everything fell out in a harmoniously in a new capacity, even the fan connector was tightly fit and the rewound throttle turned out to be very good.
Now the regulator. To simplify the task with different shunts there, we do this: we buy a ready-made ammeter and a voltmeter in China, or in the local market (for sure there can be found in the discovers). You can buy combined. But, you must not forget that they have 10a current ceiling! Therefore, in the regulator scheme, you will have to limit the current current at this mark. Here I will describe an option for individual appliances without adjusting the current with a limitation of a maximum of 10a. Regulator circuit:
To make the current limit adjustment, it is necessary to put an alternating resistor 10k, as well as R9 instead of R7 and R8. Then it will be possible to use the all-hander. Also worth paying attention to R5. In this case, its resistance is 5.6, because our ammeter is a shunt 50mΩ. For other options R5 \u003d 280 / R Shunts. Since we took a voltmeter one of the cheapest, so it should be modified a little, so that it can measure voltages from 0V, and not from 4.5V as the manufacturer did. The entire alteration lies in the separation of power circuits and measurements by deleting diode D1. There we have a wire - this is + v power. The measured part remained unchanged.
The regulator board with the location of the elements is shown below. Image for laser-ironing method of manufacture separate file REGULATOR.BMP with a resolution of 300dpi. Also in the archive there are both files for editing in Eagle. Last Off. Version can be downloaded here: www.cadsoftusa.com. On the Internet there is a lot of information about this editor.
Then we screw the finished fee at the body of the case through the insulating spacers, for example, sliced \u200b\u200bfrom the exhaust chop-chop-chups height of 5-6 mm. Well, not to forget to do the pre-all the necessary cuts for measuring and other devices.
Pre-assemble and test under load:
Just look at the compliance with the testimony of various Chinese devices. And below already with the "normal" load. This is a main light automotive lamp. As you can see - there is no small 75W. At the same time, do not forget to shove the oscilloscope there, and see the ripples about 50mv. If it is more, then we remember about the "large" electrolytes along the high side of a 220uf capacity and immediately forget after replacement to normal 680uf container for example.
In principle, you can stop at this, but in order to give a more pleasant look to the device, well, so that it does not look like a self-catering by 100%, we do the following: we leave our burgolds, climb the floor above and with the first door you take off the useless plate.
As you can see, someone has already visited us here
In general, on the quiet, we do this dirty business and start working with files of different styles and parallel to master AutoCAD.
Then on the sandpaper I drag a piece of three-fourth tube and from a sufficiently soft rubber of the desired thickness, we cut down the legs with superclaim.
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As a result, we get a fairly decent device:
It should be noted a few moments. The most important thing is not to forget that the GND of the power supply and output chains should not be connectedTherefore, it is necessary to exclude the connection between the case and GND of BP. For convenience, it is advisable to make a fuse, like on my photo. Well, to try to maximize the missing elements of the input filter, they are most likely not at all at the source.
Here is another pair of options for such devices:
On the left 2-storey ATX case with an all-handed, and on the right is strongly converted old AT case from the computer.
The master, the description of the device of which in the first part, setting the goal of making a power supply with adjustment, did not complicate the case and simply used the boards that were idle. The second option involves the use of even more common material - adjustment was added to the usual unit, perhaps, this is a very promising solution, despite the fact that the desired characteristics will not be lost and you can not even implement the idea of \u200b\u200byour own handwritten. In the bonus, two more options are completely simple schemes With all detailed explanations for beginners. So, your choice is 4 ways.
Tell how to make an adjustable power supply from an unnecessary computer board. The master took the computer board and saw a block that feeds the RAM.
So he looks like.
Determine which details need to be taken, which are not to cut what is needed to have all the components of the power supply. Usually, the pulse unit for supplying the current to the computer consists of a chip, PWM controller, key transistors, output choke and output capacitor, input capacitor. On the board also for some reason there is an input throttle. He also left him. Key transistors - maybe two, three. There is a seat of 3 transistor, but in the diagram is not used.
The chime of the controller chime itself may look like this. Here it is under a magnifying glass.
Maybe look like a square with small conclusions from all sides. This is a typical PWM controller on the laptop board.
This is the power supply unit pulsed on the video card.
Similarly, the power supply for the processor also looks. We see the PWM controller and several processor power channels. 3 transistors in this case. Choke and condenser. This is one channel.
Three transistors, choke, condenser - second channel. 3 channel. And two more channels for other purposes.
You know what the PHI controller looks like, look under the magnifying glass of its marking, look for Datasheet on the Internet, download pDF file. And watch the scheme so that nothing is imagined.
The scheme see the PHIM controller, but in the edges indicated, the conclusions are numbered.
Denote transistors. This is a throttle. This is a condenser output and a capacitor input. Input voltage in the range from 1.5 to 19 volts, but the voltage power supply of the PWM controller must be from 5 volts to 12 volts. That is, it may turn out that a separate power supply will be required to power the PWM controller. All the binding, resistors and capacitors, do not be afraid. It does not need to know. Everything is on the board, you do not collect a PWM controller, but use ready. You need to know only 2 resistors - they set the output voltage.
Resistor divider. Its entirely that the signal from the output is to reduce to about 1 volt and submit to the FIDBEK PWM controller input. In short, then changing the rating of resistors, we can adjust the output voltage. In the case shown, instead of the Fidbek resistor, the master put a stroke resistor at 10 kilo. This was sufficient to adjust the output voltage from 1 volt to about 12 volts. Unfortunately, not at all PWM controllers is possible. For example, on the PWM controllers of processors and video cards so that it is possible to customize the voltage, the ability to overclock the output voltage. You can change the output voltage of such a PWM controller per all with jumpers.
So, knowing what the PHIM controller looks like, the elements that are needed can already cut the power supply. But it is necessary to do it carefully, because around the PWM controller there are tracks that may be needed. For example, you can see - the track goes from the transistor base to the PWM controller. It was difficult to keep it, I had to carefully cut down.
Using the test tester and focusing on the scheme, soldered wires. Also using the tester, I found 6 with a PWM controller and sounded feedback resistors. The resistor was located RFD, it was falling out and instead of it from the exit, a trimming resistor on 10 kiloma soldered to adjust the output voltage, also by means of calling that the power of the PWM controller is directly related to the input line of power. This means that it is not possible to feed on the entrance more than 12 volts, so as not to burn the PWM controller.
Let's see how the power supply looks in the work.
Speed \u200b\u200bplug for input voltage, voltage indicator and output wires. We connect the external nutrition of 12 volts. The indicator lights up. Already configured for a voltage of 9.2 volts. Let's try to adjust the power supply with a screwdriver.
It's time to check out what the power supply is capable of. He took a wooden bar and self-made wire resistor from nichrome wire. Its resistance is low and together with the tester shoes is 1.7 ohms. We turn on the multimeter to the ammeter mode, connect it sequentially to the resistor. See what happens - the resistor is glowing to red, the outlet voltage is practically not changed, and the current is about 4 amps.
Previously, the master has already done similar power blocks. One carved with your own hands from the laptop board.
This is the so-called duty stress. Two sources by 3.3 volts and 5 volts. Made him on a 3D printer housing. You can also see an article where a similar adjustable power supply was done, also cut out from the laptop board (https://electro-repair.livejournal.com/3645.html). This is also the PWM memory controller.
How to make a regulatory BP from the usual, from the printer
Will talk about power supply printer Canon., inkjet. They have a lot of anyone. This is essentially a separate device, the printer holds on the latch.
Its characteristics: 24 volts, 0.7 amps.
It took the power supply for homemade drills. It is just suitable for power. But there is one nuance - if you connect it so, we will receive only 7 volts at the exit. Triple outlet, connector and get only 7 volts. How to get 24 volts?
How to get 24 volts without disassembled block?
Well, the easiest is to close the plus with an average exit and get 24 volts.
Let's try to do. We connect the power supply to the network 220. We take the device and try to measure. Connect and see at the exit of 7 volts.
He has no central connector involved. If we take and connect to two at the same time, the voltage is visible 24 volts. This is the easiest way to make this power supply unit without disassembled, issued 24 volts.
A home-made regulator is required so that in some limits you can adjust the voltage. From 10 volts to the maximum. It is easy to do it. What is needed for this? To begin with, open the power supply itself. It is usually punctured. How to open it to not damage the case. You do not need to get a bit, rise. Take the woods as much as there is a rubber cive. We put on a solid surface and on the seam of mupims. Glue leaves. Then all parties were attracted well. The glue is wonderful ways and everything is revealed. Inside we see the power supply.
Get a fee. Such BP is easy to remake on the desired voltage and can also be adjusted. On the back, if you flip, there is an adjustable TL431 stabilion. On the other hand, I will see the average contact goes to the base of the transistor Q51.
If we supply the voltage, then this transistor opens and 2.5 volts appear on the resistive divider to appear for the work of Stabitron. And at the output, 24 volts appear. This is the easiest option. How to start it can still be thrown into the transistor Q51 and put the jumper instead of the resistor R 57 and that's it. When we turn on, always at the output of 24 volts.
How to make adjustment?
You can change the voltage, make 12 volts from it. But in particular the master, it is not necessary. It is necessary to make adjustable. How to do? This transistor is discharged and instead of a resistor 57 by 38 kiloma we will put adjustable. There is an old Soviet for 3.3 kiloma. You can put from 4.7 to 10, which is. From this resistor, only the minimum voltage to which it will be able to lower it is to. 3.3 is low and no need. Engines planned to put 24 volts. And just from 10 volts to 24 - normally. Who needs another voltage, you can resist a rapid resistor.
Let's proceed, we will get enough. Take a soldering iron, hairdryer. Dredged the transistor and resistor.
Speed \u200b\u200bvariable resistor and try to enable. Same 220 volts, we see 7 volts on our device and start rotating the variable resistor. The voltage rose to 24 volts and rotate smoothly smoothly, it drops - 17-15-14 that is, it is reduced to 7 volts. In particular, installed by 3.3 com. And our alteration was quite successful. That is, for purposes of 7 to 24 volts, quite acceptable voltage adjustment.
This option turned out. Put a variable resistor. The handle turned out to be an adjustable power supply - quite comfortable.
Video channel "Technar".
Such packages are easy to find in China. I came across an interesting store, which sells used food blocks from different printers, laptops and netbooks. They disassemble and sell fees themselves, fully working on different voltages and currents. The biggest plus is that they disassemble the corporate equipment and all the power supply units are high-quality, with good details, all have filters.
Photos are different power supplies, there are a penny, almost freebies.
Simple block with adjustment
Simple version of the self-made device for powering devices with adjustment. The scheme is popular, it is common on the Internet and showed its effectiveness. But there are both restrictions that are shown on the video along with all the instructions for the manufacture of the regulated power supply.
Homemade adjustable block on one transistor
Which one can make the most simple regulated power supply? It will work on the LM317 chip. It is already almost a power supply. It can be made as a power-adjustable power supply and stream. In this video, the lesson shows a device with voltage adjustment. The master found a simple scheme. Input voltage Maximum 40 volts. Output from 1.2 to 37 volts. Maximum output current 1.5 amp. 
Without heat sink, no radiator maximum power can be only 1 watt. And with a radiator 10 watts. List of radio components. 
Start assembly 
Connect to the device output electronic load. Let's see how well the current holds. Improve at a minimum. 7.7 Volt, 30 milliammeter.
Everything is adjustable. Expose 3 volts and add a current. On the power supply to put limit only more. We translate the toggle switch to the top position. Now 0.5 amp. The microcircuit began to warm up. There is nothing to do without the heat sink. I found some kind of plate, for a while, but enough. Let's try again. There is drawdown. But the unit works. Voltage adjustment goes. We can insert this scheme to stand.
Video RadioBlogful. The video blog of the solder.
Adjustable voltage source from 5 to 12 volts
Continuing our ATX Power Supply Guide to the desktop power supply, one very good addition to this is the LM317T positive voltage stabilizer.
LM317T is an adjustable 3-pin positive voltage stabilizer capable of supplying various constant voltage outputs other than a constant voltage source +5 or +12 V, or as a variable output voltage from several volts to some maximum value, all with currents about 1, 5 amp.
Using a small number of additional schemes added to the power supply output, we can get a desktop power supply that can operate in the range of fixed or alternating stresses, both positive and negative by nature. In fact, it is much easier than you think, since the transformer, straightening and smoothing has already been made in advance, and everything that we need to do is connect our additional chain to the output of the yellow wire +12 volts. But, first, let's look at the fixed output voltage.
Fixed 9B power supply
The standard T-220 case has a wide variety of three-pole voltage regulators, while the most popular fixed voltage stabilizer is the positive 78xx series regulators, which range from a very common fixed voltage stabilizer 7805 +5 V to 7824, + 24V fixed voltage regulator. There is also a series of fixed negative 79xx series voltage regulators, which create an additional negative voltage from -5 to -24 volts, but in this lesson we will use only positive types. 78xx .
A fixed 3-pin regulator is useful in applications where the adjustable output is not required, which makes the output power source simple, but very flexible, since the output voltage depends only on the selected regulator. They are called 3-pin voltage regulators, because they have only three terminals for connecting, and this is respectively entrance , Common and Output .
The input voltage for the regulator will be the yellow wire + 12 V from the power supply (or separate transformer power supply), which connects between the input and common terminals. Stabilized +9 volts is taken through output and general, as shown.
Voltage regulator circuit
So, suppose we want to get the output voltage +9 in from our desktop power supply, then all that we need to do is connect the voltage regulator + 9 to the yellow wire + 12 V. Since the power supply has already performed straightening and smoothing up exit + 12 V, only required additional components: Condenser at the inlet and the other at the output.
These additional capacitors contribute to the stability of the regulator and can be in the range from 100 to 330 NF. An additional output capacitor with a capacity of 100 μF helps to smooth out the characteristic ripples, providing a good transition process. This capacitor of a large value, located at the output of the power supply circuit, is usually called the "smoothing capacitor".
These series regulators 78xx Give the maximum output current of about 1.5 A with fixed stabilized stresses 5, 6, 8, 9, 12, 15, 18 and 24 V, respectively. But what if we want the output voltage to be + 9 in, but had only a regulator 7805, + 5 in?. The output + 5 in 7805 refers to the terminal "Earth, GND" or "0 B".
If we had increased this voltage on contact 2 with 4 V to 4 V, the output would also increase by 4 B under the condition of sufficient input voltage. Then, placing a small 4-volt (the nearest preferred value of 4.3 c) of the zener diode between the contact 2 of the regulator and the mass, we can force 7805 5 to the stabilizer generate the output voltage +9 B, as shown in the figure.
Increase the output voltage
So, how it works. Stabilodron 4.3 V requires reverse bias current about 5 mA to maintain exit with a regulator that consumes about 0.5 mA. This full current 5.5 mA is fed through the "R1" resistor from the output contact 3.
Thus, the value of the resistor necessary for the regulator 7805 will be R \u003d 5 V / 5.5 MA \u003d 910 Ohm. The d1 diode D1, connected via the input and output terminals, is designed to protect and prevents the controller to offset when the input supply voltage is turned off, and the output power remains on or active for a short period of time due to high inductance. Load, such as a solenoid or engine.
Then we can use 3-pin voltage regulators and a suitable stabilion to obtain different fixed output voltages from our previous power source in the range from + 5V to + 12V. But we can improve this design, replacing a constant voltage stabilizer on a voltage regulator, such as LM317T. .
Source of alternating voltage
LM317T is a fully adjustable 3-pin positive voltage stabilizer capable of feeding at 1.5 and output voltage in the range from 1.25 V to just over 30 volts. Using the ratio of two resistance, one of which is a fixed value, and the other variable (or both fixed), we can set the output voltage at the desired level with the corresponding input voltage in the range from 3 to 40 volts.
The LM317T alternating voltage regulator also has built-in current limiting functions and thermal shutdown, which makes it resistant to short circuit and is ideal for any low-voltage or home desktop power supply.
The output voltage of LM317T is determined by the ratio of two feedback resistors R1 and R2, which form a network of potential divisors at the output terminal, as shown below.
LM317T AC voltage regulator
The voltage on the feedback R1 resistor is a constant reference voltage of 1.25 V, V REF, created between the "output" and "adjustment" terminal. The current of the adjusting terminal is a constant current of 100 μA. Since the reference voltage through the R1 resistor is a constant, constant current, I will flow through another resistor R2, resulting in an output voltage:
Then any current flowing through the resistor R1 also flows through the R2 resistor (ignoring a very small current on the adjusting terminal), and the sum of the voltage drops on R1 and R2 is equal to the output voltage VOUT. Obviously, the input voltage VIN must be at least 2.5 in more than the desired output voltage to power the regulator.
In addition, LM317T has a very good load regulation, provided that the minimum load current exceeds 10 mA. Thus, to maintain a constant reference voltage of 1.25V, the minimum value of the feedback resistor R1 must be 1.25V / 10MA \u003d 120 ohms, and this value can vary from 120 ohms to 1000 ohms with typical values \u200b\u200bof R 1 is approximately 220Ω to 240Ω For good stability.
If we know the value of the desired output voltage, Vout and the feedback resistor R1, say, 240 ohms, then we can calculate the value of the resistor R2 from the above equation. For example, our starting output voltage 9 V will give a resistive value for R2:
R1. ((Vout / 1.25) -1) \u003d 240. ((9 / 1.25) -1) \u003d 1 488 ohm
or 1500 ohms (1 com) to the nearest preferred value.
Of course, in practice, R1 and R2 resistors usually replace the potentiometer to generate an alternating voltage source or several switched pre-installed resistances if several fixed output voltages are required.
But in order to reduce the mathematical calculations required to calculate the value of the resistor R2, each time we need a certain voltage, we can use standard resistance tables, as shown below, which give us the output voltage of the regulators for various ratios of resistors R1 and R2 with using the E24 resistance values,
R1 resistance ratio R2
| R2 value | R1 resistor value | ||||||||
| 150 | 180 | 220 | 240 | 270 | 330 | 370 | 390 | 470 | |
| 100 | 2,08 | 1,94 | 1,82 | 1,77 | 1,71 | 1,63 | 1,59 | 1,57 | 1,52 |
| 120 | 2,25 | 2,08 | 1,93 | 1,88 | 1,81 | 1,70 | 1,66 | 1,63 | 1,57 |
| 150 | 2,50 | 2,29 | 2,10 | 2,03 | 1,94 | 1,82 | 1,76 | 1,73 | 1,65 |
| 180 | 2,75 | 2,50 | 2,27 | 2,19 | 2,08 | 1,93 | 1,86 | 1,83 | 1,73 |
| 220 | 3,08 | 2,78 | 2,50 | 2,40 | 2,27 | 2,08 | 1,99 | 1,96 | 1,84 |
| 240 | 3,25 | 2,92 | 2,61 | 2,50 | 2,36 | 2,16 | 2,06 | 2,02 | 1,89 |
| 270 | 3,50 | 3,13 | 2,78 | 2,66 | 2,50 | 2,27 | 2,16 | 2,12 | 1,97 |
| 330 | 4,00 | 3,54 | 3,13 | 2,97 | 2,78 | 2,50 | 2,36 | 2,31 | 2,13 |
| 370 | 4,33 | 3,82 | 3,35 | 3,18 | 2,96 | 2,65 | 2,50 | 2,44 | 2,23 |
| 390 | 4,50 | 3,96 | 3,47 | 3,28 | 3,06 | 2,73 | 2,57 | 2,50 | 2,29 |
| 470 | 5,17 | 4,51 | 3,92 | 3,70 | 3,43 | 3,03 | 2,84 | 2,76 | 2,50 |
| 560 | 5,92 | 5,14 | 4,43 | 4,17 | 3,84 | 3,37 | 3,14 | 3,04 | 2,74 |
| 680 | 6,92 | 5,97 | 5,11 | 4,79 | 4,40 | 3,83 | 3,55 | 3,43 | 3,06 |
| 820 | 8,08 | 6,94 | 5,91 | 5,52 | 5,05 | 4,36 | 4,02 | 3,88 | 3,43 |
| 1000 | 9,58 | 8,19 | 6,93 | 6,46 | 5,88 | 5,04 | 4,63 | 4,46 | 3,91 |
| 1200 | 11,25 | 9,58 | 8,07 | 7,50 | 6,81 | 5,80 | 5,30 | 5,10 | 4,44 |
| 1500 | 13,75 | 11,67 | 9,77 | 9,06 | 8,19 | 6,93 | 6,32 | 6,06 | 5,24 |
By changing the R2 resistor for a potentiometer by 2 kΩ, we can control the range of output voltage of our desktop power supply from about 1.25 volts to the maximum output voltage of 10.75 (12-1.25) volts. Then our final modified alternating power circuit is shown below.
AC power supply circuit
We can slightly improve our basic voltage regulator scheme by connecting an ammeter and a voltmeter to the output terminals. These devices will visually display the current and voltage at the output of the alternating voltage regulator. If desired, a high-speed fuse can also be enabled to ensure additional short-circuit protection, as shown in the figure.
Disadvantages of LM317T.
One of the main disadvantages of using LM317T as a part of the AC power supply circuit for voltage control is that up to 2.5 volts drops or is lost as heat through the regulator. For example, if the required output voltage must be +9 volts, the input voltage must be as long as 12 volts or more if the output voltage should remain stable under the conditions of maximum load. This voltage drop on the regulator is called "dropping". Also because of this voltage drop requires some form of the radiator to maintain the regulator in the cold state.
Fortunately, alternating voltage regulators with low voltage drops are available, such as a low voltage regulator with a low voltage drop of National Semiconductor "LM2941T", which has low voltage Disable only 0.9 V at maximum load. This low voltage drop is expensive, since this device is capable of issuing only 1.0 amps with an alternating voltage output from 5 to 20 volts. However, we can use this device to obtain the output voltage of about 11.1 V, just below the input voltage.
So, to sum up the result, our desktop power supply, which we made from the old PC power supply in the previous tutorialmay be converted to provide a source of alternating voltage using LM317T to regulate the voltage. By connecting the input of this device through the yellow output wire + 12 in the power supply unit, we can have a fixed voltage + 5 V, + 12 V and a variable output voltage in the range from 2 to 10 volts at a maximum output current 1.5 A.
Why do Ik-port need? Such a device allows you to create a steady connection between the computer and other devices (equipped with IR ports) without the use of wires. For example, it can be a scanner or printer. Although now most users acquire such a device for connecting a desktop computer with pocket computer Or, which is significantly more often, a cell phone. The last two devices have a fairly primitive input system and, of course, its expansion increases the comfort of working with information. Mobile phone has become a convenient device for most computers users. IR port, which is equipped with many models of phones, allows you to edit content notebook Apparatus through an ordinary computer. You can change the logo on the display without any special problems or deliver the call melody. A fairly interesting feature that appears at the owner of the mobile device is a network monitoring that will give the most comprehensive information on the network. It is impossible not to say about such a service of almost all cellular operators as mobile Internet. In this case, you can go to the worldwide network through your mobile phone. In other words, you become Internet users anywhere where the operator needs you. It is quite expensive, but there is no alternative to solving this problem in some cases. Let's get acquainted in more detail with this wonderful device.
Types of IR ports (by connecting):
Second and third types are universal devices. In other words, if you buy such an IR transceiver, he will stand on your computer without complications. If you attracted an IR port, which is connected to the IRDA maternal connector, then problems may arise. Carefully read the instructions and consult with the seller. For example, the IR port of ASUS works only on the motherboard of the same manufacturer. Very comfortable IR ports make one of the Chinese companies (there is no name of the manufacturer's plastic bag on the polyethylene sachet). Connector for connecting to IRDA is made on the principle of "Collect me myself". On the one hand, he obviously lacks mechanical strength, and insert it into the connector of the motherboard is very difficult. But on the other hand, you can easily, without resorting to the assistance of the soldering iron and tweezers, collect the desired connector, thereby ensuring the necessary "pin" compatibility. Such flexibility of the solution makes it very attractive for purchase. Although the quality of Chinese IR ports ... Let's not be about bad. In the future, we will talk about the characteristics of such devices.
Working conditions
IR communication devices cannot be called very capricious, but still you need to tell a little about the conditions of their operation. First of all, it is worth knowing that the wavelength of the work of IR ports lies in the range from 850 to 900 nm. Most often this value is 880 nm. So organize strong interference is quite simple. Let's start with examples:
- The windows of the apartment located on the fifth floor come out on the west side. Closer to the evening, the IR receiver / transmitter stopped seeing cellular telephoneequipped with a similar system. This bundle was on the table and was not covered with anything. The cause of interference was found without any problems. Bright spring sun has become wines to everything. When working with IR devices, beware of direct sunlight.
- In the evening when the lamp is turned on daylight The situation was repeated. However, it is worth noting that the connection was still, but very often broke. Daylight lamp must be covered or off during the operation of IR devices.
- TV, which is located in close proximity to the desktop, is equipped with a remote control. remote control. When switching channels or any other manipulations with the "slive working programm It properly issued a message that in direct proximity, an extraneous IR device works and required to turn it off. It hosted this data transmission or not - it is unknown, but until the remote control was removed (you can read "was turned off"), it was not possible to do anything with the program. When working with an IR device, remove all foreign IR transmitters in the IR port area.
Exclude all sources of IR waves of a range of 850-900 nm from the direct scope of the IR receiver. Reflected waves can bring problems, but to a lesser extent. In a word, all the interference is not foreseen, but you can always remove their cause. The working distance between the two IR devices should not exceed one meter. Otherwise, the system will work unstable. The identity diagram of the IR port, which is indicated in the instructions for it, to put it mildly, does not withstand any criticism. Try to place the devices directly opposite each other. Foreign items placed between the IR port and the working device will not contribute better work. There were cases where the cell phone in the case tried to connect through the IR port to the computer. Nothing turned out until the translucent case was removed.
Connection
Connect an IR port to personal computer quite simple. But in any case, it is recommended to spend ten minutes on a careful study of instructions for the device. Even if you don't know anything new from it, you will feel confident during installation.
Hardware
Connect the IR port to the COM port connector. Remember the COM port number - this is useful to you later. When connecting the IR port to the IRDA-connector of the motherboard, unlock your housing system Block And, having read the description of your motherboard, insert the connector in the desired socket (four-pin line). The first wire is marked on the board number 1 or indicated in the description of the motherboard. The first IR port connector wire has a flower label. Display the rear cap free space and you can collect the case. Connect the flexible wire connector with an IR receiver / transmitter to the connector on the plug. The socket and the connector are very similar to the PS / 2-connector.
Software
Here is a description of the setup. software For the MS Windows 98 operating system. For other operating systems from Microsoft, it is similar. Connect the IR port to computers with other operating systems is possible, but in the description of the IR port indicated: "Designed to work with operational windows systems 95 and higher. " Experiment, maybe you all come out.
When installing an IR port on COM, you will be waiting for a happy swimming. Included to the device there is a CD disk, install drivers from which will not be any difficulties. Set the port number correctly to which the IR port is connected. Look, whether the COM port does not occupy another device, for example, internal modem. Also check the BIOS settings for a parallel port - it must be set to ECP mode, and not in Normal or SPP (default value).
When installing the internal IR port, it is worth making a few more manipulations with your hands. First of all, log in to the BIOS and turn on the second COM port. As a rule, below is the option on the inclusion of IRDA. Activate it. Next, install a half-duplex connection. If your BIOS contains other settings, then put them in the default mode. There will be problems - read the instructions and experiment with the settings. Harm or physical damage to your computer you will not be able to bring.
Load operating system. If you did everything correctly, the new device itself will be detected by the system. Next, you will be offered to select the type of device. For reliability, do it manually. Select "IR devices", and then the standard type of device. Install the virtual port and remember its number. It will need you to configure most programs. The "Properties: System" menu will acquire another item - "IR communication devices".
Overload the machine.
After that, an icon in the form of a flashing light will appear in the lower right corner.
Opening it, you will see the properties of IR-Communications.
Among all the settings it is worth allocating only "modes". Here you can include an IR connection and set the time through which the IR port will search for IR devices in a direct zone of visibility. The "Restriction of the Speed \u200b\u200bof the exchange rate before:" can be disabled.
Now, if you put another activated IR device in the visibility zone, then hear the sound and see this on the screen:
All your IR port is fully configured, now you can use it. For example, send a picture from the phone to a computer. Next, we suggest you to look at the most fashionable and popular use of the IR port device in conjunction with mobile phone - Mobile Internet.
Mobile Internet
Most operators cellular networkWorking in the GSM-900/1800 standard offer such a service as a "mobile Internet". What it is? With the help of a cell phone equipped with an IR receiver / transmitter and modem, you can enter the World Wide Web and use it as an ordinary Dial-UP connection. The advantages of this entry into the network are obvious. First of all, you will untie yourself from the annoying telephone wiring and become mobile (if you use a laptop). But the network through the mobile phone has its own minuses. We recommend to find out in advance how much (in monetary equivalent) will fall out to you such entertainment. The second minus lies in the speed of the mobile Internet. It is 9600 BPS and no more. With the commissioning of new technologies, this figure may soon increase. Mobile Internet configuration does not take much time. Here are the order of your actions. Make sure your cell phone is equipped with an IR port and modem. Turn on the IR port on your mobile phone. After that, place it in the action zone of the IR port connected to the computer (about 1 m).
Now you need to configure the work of the modem built into the phone. For this, you need to enter the "Setup" menu, then the "modem" and manually install the "standard modem 19200" (if you have a special driver for your cellular modem, then put it). When installing, do not forget to specify the correct virtual port, which was created when the IR port is connected to your computer. All, the modem setting is complete. Overload the system. To set the connection you need to create a "new connection" (parameters for it you can learn from your cellular operator). Internet through a cell phone at your disposal. Mobile Internet is a fairly important and interesting addition to your computer.
Instead of imprisonment
IR connection of a computer with other devices acts on comparatively a short distance. However, its ability is widely used among mobile equipment. Most likely, in the near future, communications on IR rays will give way to more perfect types of communication (for example, Bluetooth - several tens of meters). But so far none of the manufacturers motherboards I did not abandon IRDA, and you can buy an IR port with a calm soul. Although, before making a purchase, make sure that your phone and computer can transmit data in the infrared range. We hope that you, having read this article, will be able to choose and enable the IR port without any special problems.
