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Do-it-yourself high voltage generator. High voltage and more. How it works

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My high voltage generator HV) I use in many of my projects ( , ):

Elements -
1 - switch
2 - varistor
3 - E/M interference suppression capacitor
4 - step-down transformer from the UPS
5 - rectifier (Schottky diodes) on the radiator
6 - smoothing filter capacitors
7 - voltage regulator 10 V
8 - generator of rectangular pulses with adjustable duty cycle variable resistor

10 - IRF540 MOSFETs connected in parallel, mounted on a radiator
11 - high-voltage coil on a ferrite core from the monitor
12 - high voltage output
13 - electric arc

The source circuit is fairly standard, based on the flyback converter circuit ( flyback converter):

Input circuits

Varistor serves for overvoltage protection:

S- disk varistor
10 - disc diameter 10 mm
K- error 10%
275 - max. AC voltage 275 V

Capacitor C reduces the interference generated by the generator in the power supply network. An interference suppression capacitor is used as it. X type.

DC voltage source

Transformer - from an uninterruptible power supply:

Transformer primary winding Tr connected to mains voltage 220 V, and secondary - to the bridge rectifier VD1.

The effective value of the voltage at the output of the secondary winding is 16 V.

The rectifier is assembled from three cases of dual Schottky diodes mounted on a radiator - SBL2040CT, SBL1040CT:

SBL 2040 CT- max. average rectified current 20 A, max. peak reverse voltage 40 V, max. effective reverse voltage 28 V
connected in parallel:
SBL 1040 CT- max. average rectified current 10 A, max. peak reverse voltage 40 V, max. effective reverse voltage 28 V
SBL 1640 - max. average rectified current 16 A, max. peak reverse voltage 40 V, max. effective reverse voltage 28 V

The pulsating voltage at the rectifier output is smoothed out by filter capacitors: electrolytic CapXon C1, C2 10,000 uF for 50 V and ceramic C3 capacitance 150 nF. Then a constant voltage (20.5 V) is supplied to the key and a voltage stabilizer, at the output of which a voltage of 10 V operates, which serves to power the pulse generator.

Voltage stabilizer assembled on a microcircuit IL317:

Throttle L and capacitor C serve to smooth out voltage ripples.
Light-emitting diode VD3 connected through a ballast resistor R4, serves to indicate the presence of voltage at the output.
Variable resistor R2 serves to adjust the output voltage level (10 V).

Pulse generator

The generator is assembled on a timer NE555 and produces rectangular pulses. A feature of this generator is the ability to change the duty cycle of the pulses using a variable resistor R3 without changing their frequencies. From the duty cycle of the pulses, i.e. the voltage level on the secondary winding of the transformer depends on the ratio between the duration of the on and off state of the key.

Ra = R1+ top R3
Rb= lower part R3 + R2
duration "1" $T1 = 0.67 \cdot Ra \cdot C$
duration "0" $T2 = 0.67 \cdot Rb \cdot C$
period $T = T1 + T2$
frequency $f = (1.49 \over ((Ra + Rb)) \cdot C)$

When moving the variable resistor slider R3 total resistance Ra + Rb = R1 + R2 + R3 does not change, therefore, the pulse repetition rate does not change, but only the ratio between Ra and Rb, and, consequently, the duty cycle of the pulses changes.

key and
The pulses from the generator are controlled through the driver by a key on two connected in parallel -ah( - metal-oxide-semiconductor field effect transistor, MOSFET (metal-oxide-semiconductor), MIS transistor (metal-insulator-semiconductor), insulated gate field-effect transistor) IRF540N in the building TO-220 mounted on a massive radiator:

G- shutter
D- stock
S- source
For transistor IRF540N the maximum voltage "drain-source" is VDS = 100 volts, and the maximum drain current I D = 33/110 amps. This transistor has low on-resistance. RDS(on) = 44 milliohms. The opening voltage of the transistor is VGS(th) = 4 volts. Working temperature- before 175° C .
You can also use transistors. IRFP250N in the building TO-247.

Driver needed for more reliable control -transistors. In the simplest case, it can be assembled from two transistors ( n-p-n and p-n-p):

Resistor R1 limits gate current when turned on -a,a diode VD1 creates a path for the gate capacitance to discharge when turned off.

Closes / opens the primary circuit of a high-voltage transformer, which is used as a transformer line scanning("linear", flyback transformer (FBT)) from an old monitor Samsung SyncMaster 3Ne:

The circuit diagram of the monitor shows the high voltage output HV line transformer T402 (FCO-14AG-42), connected to the anode of the kinescope CRT1:

From the transformer, I used only the core, since diodes are built into the horizontal transformer, which are filled with resin and cannot be removed.
The core of such a transformer is made of ferrite and consists of two halves:

To prevent saturation in the core with a plastic spacer ( spacer) is an air gap.
I wound the secondary winding with a large number (~ 500) turns of thin wire (resistance ~ 34 ohms), and the primary with a thick wire with a small number of turns.

Sharp current drops in the primary winding of the transformer when turned off -a induce high-voltage pulses in the secondary winding. This consumes the energy of the magnetic field, accumulated with increasing current in the primary winding. The secondary leads can either be connected to electrodes to produce, for example, an electric arc, or connected to a rectifier to produce a high DC voltage.

Diode VD1 and resistor R(snubber (snubber) chain) limit the self-induction voltage pulse on the primary winding of the transformer when the key is opened.

Modeling a high voltage generator
The results of modeling processes in the high voltage generator in the program LTspice are presented below:

The first graph shows how the current in the primary winding increases according to the exponential law (1-2), then abruptly breaks off at the moment the key is opened (2).
The voltage on the secondary winding reacts slightly to a smooth increase in current in the primary winding (1), but increases sharply in the event of a power failure (2). In the interval (2-3) there is no current in the primary winding (the key is turned off), and then it starts to increase again (3).

Before we proceed to the description of the proposed high voltage source for assembly, we recall the need to observe general safety precautions when working with high voltages. Although this device produces an extremely low level of output current, it can be dangerous and will cause quite a nasty and painful shock if accidentally touched in the wrong place. From a safety point of view, this is one of the safest high voltage sources, since the output current is comparable to that of conventional stun guns. The high voltage at the output terminals is a direct current of about 10-20 kilovolts, and if you connect a spark gap, you can get an arc of 15 mm.

High voltage source circuit

The voltage can be adjusted by changing the number of stages in the multiplier, for example, if you want it to light neon lamps - you can use one, if you want spark plugs to work - you can use two or three, and if you need a higher voltage - you can use 4, 5 or more. Fewer stages means less voltage but more current, which can increase the danger of this device. It's a paradox, but the higher the voltage, the less difficult it will be to cause damage due to the supply, as the current drops to a negligible level.

How it works

After pressing the button, the IR diode turns on and the light beam hits the optocoupler sensor, this sensor has an output resistance of about 50 ohms, which is enough to turn on the 2n2222 transistor. This transistor supplies battery power to power the 555 timer. The frequency and duty cycle of the pulses can be adjusted by changing the ratings of the strapping components. In this case, the frequency can be adjusted using a potentiometer. These oscillations, through the transistor BD679, which amplifies the current pulses, are fed to the primary coil. An alternating voltage, increased by 1000 times, is removed from the secondary and rectified by a high-voltage multiplier.

Parts for assembling the circuit

Microcircuit - any timer of the KR1006VI1 series. For the coil - a transformer with a winding resistance ratio of 8 Ohm: 1 kOhm. The first thing to consider when choosing a transformer is size, as the amount of power they can handle is proportional to their size. For example, the size of a large coin will give us more power than a small transformer.

The first thing to do to rewind it is to remove the ferrite core to access the coil itself. In most transformers, the two parts are glued together, just hold the transformer with pliers over a lighter, being careful not to melt the plastic. After a minute, the glue should melt and you need to break it into two parts of the core.

Keep in mind that ferrite is very brittle and cracks quite easily. Enamelled copper wire 0.15 mm was used to wind the secondary coil. Winding almost to the point of filling, so that later one more layer of a thicker wire of 0.3 mm is enough - this will be the primary. It should have several dozen turns, about 100.

Why an optocoupler is installed here - it will provide complete galvanic isolation from the circuit, with it there will be no electrical contact between the power button, the microcircuit and the high-voltage part. If you accidentally break through the high voltage on the power supply, then you will be safe.

It is very easy to make an optocoupler, insert any IR LED and IR sensor into the heat shrink tube, as shown in the picture. As a last resort, if you don’t want to complicate things, remove all these elements and apply power by closing the K-E of the 2N2222 transistor.

Note the two switches in the circuit, this is because each hand must be used to activate the generator - this will be safe, reducing the risk of accidental activation. Also, when the device is operating, you should not touch anything other than the buttons.

When assembling the voltage multiplier, be sure to leave enough clearance between the elements. Trim any protruding leads as they can lead to corona discharges which greatly reduce efficiency.

We recommend that you insulate all exposed contacts of the multiplier with hot melt adhesive or other similar insulating material and then wrap it in heat shrink tubing or electrical tape. This will not only reduce the risk of accidental strikes, but also increase the efficiency of the circuit by reducing air losses. Also, for insurance, a piece of foam was added between the multiplier and the generator.

The current consumption should be approximately 0.5-1 amperes. If more, then the circuit is poorly configured.

HV generator testing

Two different transformers were tested - both with excellent results. The first had a smaller ferrite core and, therefore, less inductance, operated at a frequency of 2 kHz, and the other at about 1 kHz.

When starting for the first time, first check the NE555 generator to see if it works. Connect a small speaker to leg 3 - as you change the frequency, you should hear sound coming from it. If everything gets very hot, you can increase the resistance of the primary winding by winding it with a thinner wire. And a small heatsink for the transistor is recommended. Yes, and the correct tuning frequency is important to avoid this problem.

Everyone knows that in the original, the Tesla resonant transformer was made on a lamp, but with the development of electronics, it became possible to significantly reduce and simplify the dimensions. this device, if instead of a lamp you use a conventional bipolar transistor of the KT819 type or another similar in current and power. Of course, with a field effect transistor, the results will be even better, but this circuit is designed for those who are taking their first steps in assembling high voltage generators. circuit diagram device is shown in the figure:

The communication and collector coils are wound with a wire of 0.5-0.8 mm. We take any wire on a high-voltage coil, with a thickness of 0.15-0.3 mm and about 1000 turns. At the "hot" end of the high-voltage winding we put just such a spiral - everything is like in a real Tesla. In its version, I took power from a 10V 1A transformer.

Of course, with a power supply of 24V and above, the length of the corona discharge will increase significantly. After the secondary winding, there is a rectifier and a 1000uF 25V capacitor. The transistor for the generator used KT805IM. for the scheme in the archive.

And now a photo of the finished structure and the discharge itself:

Powerful high voltage generator (Kirlian apparatus), 220/40000 volts

The generator generates voltages up to 40,000 V and even higher, which can be applied to the electrodes described in previous projects.

It may be necessary to use a thicker glass or plastic plate in the electrode to avoid serious electrical shock. Although the circuit is quite powerful, its output current is low, which reduces the risk of a fatal blow if it comes into contact with any parts of the device.

However, you should be extremely careful when handling it, as the possibility of electric shock is still possible.

Attention! High voltages are dangerous. Be extremely careful when working with this circuit. It is desirable to have experience with such devices.

You can use the generator in experiments with Kirlian photography (electrophotography) and other paranormal experiments, such as those related to plasma or ionization.

The circuit uses conventional components, its output power is about 20 watts.

Below are some specifications of the device:

power supply voltage - 117 V or 220/240 V (AC mains);
output voltage - up to 40 kV (depending on the high-voltage transformer);
output power - from 5 to 25 W (depending on the components used);
number of transistors - 1;
operating frequency - from 2 to 15 kHz.

Principle of operation

The scheme shown in fig. 2.63, consists of a single-transistor generator, the operating frequency of which is determined by the capacitors C3 and C4 and the inductance of the primary winding of the high-voltage transformer.

Rice. 2.63 Kirlian apparatus

The project uses a powerful silicon n-p-n transistor. To remove heat, it should be mounted on a sufficiently large radiator.

Resistors R1 and R2 determine the output power by setting the current of the transistor. Its operating point is set by the resistor R3. Depending on the characteristics of the transistor, it is necessary to experimentally select the value of the resistor R3 (it should be in the range of 270 ... 470 Ohms).

As a high-voltage transformer, which also determines the operating frequency, the horizontal scan output transformer of the TV (linear transformer) with a ferrite core is used. The primary winding consists of 20 ... 40 turns of conventional insulated wire. A very high voltage is generated on the secondary winding, which you will use in experiments.

The power supply is very simple, it is a full-wave rectifier with a step-down transformer. It is recommended to use a transformer with secondary windings providing voltage 20...25 V and currents 3...5 A.

Assembly

The list of elements is given in table. 2.13. Since the assembly requirements are not very strict, in Fig. 2.64 shows the mounting method using a mounting block. It houses small parts, such as resistors and capacitors, interconnected by surface mounting.

Table 2.13. Item List

Large parts, such as a transformer, are screwed directly to the housing.

The case is better to make plastic or wood.

Rice. 2.64. Mounting the device

The high voltage transformer can be removed from a black and white or color TV that is not working. If possible, use a TV with a diagonal of 21 inches or more: the larger the kinescope, the more voltage the line transformer of the TV should generate.

Resistors R1 and R2 - wire-wound C1 - any capacitor with a nominal value of 1500 ... 4700 uF.

Hello. Today we will talk about a very powerful and cool homemade product. Today I will assemble a powerful high-voltage generator with a voltage of about 25 kV. This scheme This is not the first time I collect, so there are no difficulties. I will try to explain everything short and simple
Perhaps I'll start with a high-voltage generator circuit. I found it when I was collecting it, and saved it just in case. Diagram of just a dozen components
As he said, he assembled the circuit for the second oscillator, the circuit is now successfully working in welding. The bottom board is the high voltage generator

While collecting, I managed to play enough with an arc sometimes reaching 3 centimeters, which was approximately 30 kV. Even then, I thought of assembling the same generator for myself, it was only necessary to assemble the appropriate components, and now the time has come

I found a Soviet-made color TV and pulled out a line scan board from it

Actually, from this board, only a line transformer and a capacitor k73-17 for 400V 0.47 uF are needed. I had a couple of them on the first generator.
I cleaned the board from the old tracks with a grinder, installed a horizontal transformer in the old place by winding two windings of 5 turns. I made a choke from the same transformer, which I will redo a little later.

Started assembling the control part of the circuit. The installation will be hinged, I don’t want to fool around with the board. Installed field effect transistors 40N60 on the radiator, through insulating gaskets

At the next stage of the assembly, I soldered powerful three-ampere Schottky diodes

The trick is to solder the capacitor between the drains of the transistors and solder the 390 Ohm resistors into the gates. I didn’t install zener diodes, since I don’t have them, but the circuit works fine without them

I soldered the transformer to the drains and rewound the inductor, since the inductance of the previous one is too small. New inductor with 50 uH inductance.

It's time to try and start the high-voltage generator. I connect the board to . In the photo, the arc is about half a centimeter, which is equal to 5kV. Power supply 20V

I tried to expand the arc to 2.5 cm, the voltage rose to 25 kV. The arc became wide and powerful, it lights a cigarette in a split second 🙂 But the wire began to melt and the experiment had to be interrupted

So that the wires do not burn, one output of the high-voltage winding was connected to a self-tapping screw screwed into the board, and a bolt was screwed onto the second.
Power supplied 20V, no-load current 0.6A

Now I'll try to ignite the arc up to 25 kV and make a measurement. The voltage dipped to 13.2V, the current consumption was 6.25A. Power consumption 82.5W, the pencil lights up without any problems at all

Unfortunately my lab can't start the arc harder and so the transformer is overloaded. We need to find something more powerful and see what else the high-voltage generator is capable of.
I shot a short video of the generator here, I hope you will be interested.