Research website of Vyacheslav Gorchilin
All articles/Electronic circuits
The electronic equivalent of the circuit breaker for spark Tesla coil with PLL

The material is dedicated to fans of powerful spark discharges, and seekers of free energy, that use for their experiments a Tesla transformer (TT). And we will consider the heart of the transformer — electronic circuit breaker which achieves the desired voltage and power. This breaker was first described by Tesla in the patent No. 787,412 and worked with two mechanical reels. Since its publication more than 100 years; during this time the technologies have changed and the entire technological structure. So we move from mechanics to modern electronics, the last applied circuit solutions in the form of a PLL, and see what happens :)

The device is made of four digital IC 74HCXX series, two output drivers signal and two voltage regulators. The breaker can work with a variety of TT in the operating range: 250 kHz .. 1 MHz (for other resonant frequencies will need to change some frequency driver and timing elements). The PLL tracks all the changes made to TT for them and automatically adjusts the breaker. The scheme produces packets of pulses and synchronized with them nizkochastotnykh signal (second CTS) that can move relative to the bundle at any phase. In addition, the paper is governed by the number of pulses and their duty cycle.

Схема электронного прерывателя искры для трансформатора Тесла с ФАПЧ
The following is a list used in the unit circuits, diodes and two modes. In parentheses are possible replacements:
Job breaker
The interrupter operates as follows. VCO (voltage controlled oscillator) chip DD1 generates pulses with a frequency F1, which must coincide with the resonant frequency of the TT. Beyond coincidence frequency and phase monitors the phase comparator, the inputs of which are designated Cin and Sin. For Cin pulses from the VCO, and Sin receives vibrations from the TT. The comparator output (PC2), through smoothing the chain R6C7, is input to VCO (Gin) and provides feedback by changing the frequency and phase of the generator depending on the parameters TT.
Formed and asinhronisations pulses from VCO served on two counters: DD2 and DD3. First, with the aid of six switches SA2 will provide a fixed phase shift between the pulse train and the low frequency F2. The phase variation is produced by different combinations of the switch. Also, with the help of the counter DD2 we get F2 itself, which with its output (leg 10) is input to driver half-bridge DA3. At the output (X3, X4), we obtain pulses with a frequency F2.

The counter DD3 is responsible for the number of pulses in a packet. By using different combinations of the switch SA3 we can get from 1 to 15 pulses per burst. For the experiments can be a fun mode when all switches are open. In this case, the output X2 of the pulses will be absent. Timing chain C8R11R12 together with the trigger DD4.2 sets the duty cycle of pulses, and its output connected to the driver output signal DA4. At the output (X2) we get packs of impulses with a frequency within the bundle F1 and the frequency between bursts — F2.

Trigger DD4.1 sinhroniziruete these counters dropping the ban on the receipt of pulses from the VCO to the DD3 at the beginning of the pack.


With the exception of DD1 all digital circuits can be replaced by a similar series КР1564 (see above). Instead 74HC7046 you can use 74HC4046, but then the diagram will be missing the detector capture phase. In this case, the chain indicator detector — R7, VD3, and an accompanying capacitor C6 will need to remove. The driver output signal for the TC4420 can be replaced by the TC4429, but then the entrance of this driver (2nd leg), through the resistor R14 will need to be connected to the inverse output of the trigger DD4.2 (the 8 foot). Driver IR2109 half-bridge is changed to the same IR2104 or IR2108. In this case the 3rd leg of these circuits must be connected to +12V.

Installation note

The diagram does not show the power pins of chips. They are standard. For the 16 pin of section: 8 — negative supply (common), 16 — plus, for the 14 pin: 7 — negative supply (common), 14 — plus. All the cons need to connect and be connected to GND and to Gnd of the stabilizer DA1. All positive findings — Out to his (or +5V). Also, the output 5 of the microcircuit DD1 (not shown in the diagram) must be connected to minus power supply. Similarly, 4 and 10 pins of the chip DD4 need to connect to plus.

Connect two tanks by 0.1 UF directly on the terminals of the driver DA4: 1-4 and 8-5. The same capacity and connect to the power pins DD1.

Insights castorocauda chains it is desirable to make it shorter. This relates to findings 6, 7, 11 and 12 of the microcircuit DD1.

The option PCB is shown below:

Печатная плата для электронного прерывателя Печатная плата для электронного прерывателя - обратная сторона
The connection of the breaker

Variants of connection of CTS can be very much, so the following is an example of just one of them. As a key VT1 work well IRFP360, IRFP460, FCH47N60. For half-bridge VT2-VT3 suitable for low voltage, for example, IRFP260. The protective diode VD5 — any high-voltage ultrafast, for example, FR607. But the diode VD6, which serves to increase the q-factor ТТ1, should be approached more carefully. Well HFA30PB60, but also work well several parallel SF56.

Special attention should be paid to the current transformer Tr, which is responsible for synchronizing the PLL. Токовый трансформатор для трансформатора Теслы For this it needs to convert the loop current, formed at the lower end ТТ1, in voltage, which is then fed to the input X1 of the circuit breaker.

The transformer is wound in a random order; here the important principle is to obtain a maximum voltage at its secondary **. It is a ferrite ring that is needed to wind more turns, but inside it there is a place for the wires with ТТ1. This ring must be worn on the wire coming from ТТ1 on the ground. For example, I worked well the ring diameter 10 mm, height 8 mm, with the number of turns is 50. Mark ferrite are here does not matter.

Схема включения электронного прерывателя

Other data, for example, by winding the TT, we are here to lead will not, because depending on the tasks they can have totally different meanings.


The circuit breaker described is well suited for seekers of free energy. But the application of schemes may be different. For example, for the so nazyvaemyh "singing of the Adzes" is used only the first TT and the audio input can be submitted to the 9 th foot DD1 through series-connected resistor 10..20kohm and the 100n capacitor.

Another option to control two transformers can be viewed here. In this scheme, as ТТ1, it is possible to apply low frequency transformer, for example, TVs.

** Standing waves can be simulated here