In life sometimes lacks the drive and entertainment — with the chaotic and mysterious crackle of a spark gap and with soaring standing next to the radio. All this can give you a high voltage generator! But if no ads, and seriously, for some experiments this generator is an essential thing. So I took this one, and not just some kind of increase TRANS to 1000V, and at 5-20 kV. But the main requirement is the ability to control the high voltage output. Digging in the net and not finding a suitable scheme, I had to invent their darling.
For the oscillator took raspostraneny Melksham — NE555, and as TRANS — FA-90 (bought on a radio market for a penny). To stabilize the supply voltage sets applied not less common PWM LM7809.
The principle of the scheme is simple: a master oscillator vibrative rectangular pulses with different duty cycles — it then depends on our output and high voltage. The duty cycle is regulated in R3 and is fed to the output key on MOSFET-transistor. The latter excites the primary winding of FA, and we get secondary high voltage.
Adjustment of R3 we can obtain as a small spark in a fraction of a millimeter, and the spark length a couple of inches.
- The output key should be put on a radiator, because at higher output voltages the current through it may exceed 5-8A.
- It is desirable that the casing be metallic (I used the case from a computer PSU), where the negative supply would be connected with him.
- The supply voltage can be increased to 15-20 Volts and get a more powerful spark, but in this case, be sure to post the spatial unit of the driving generator and the transformer. Specifies the schema itself will need to saarnisaari, since strong interference can damage semiconductor components.
