Quest for fastest and sharpest solid-state switching

[sciencisto]

no digital meter

When you want to see the true voltage or current, don't use digital meters if you are measuring something that is not pure DC or regular sin wave in range outside of ~40 to 200 Hz.
If you do use digital meters on other wave forms, you can be sure of wrong readings and in some (not rare) cases your meter is in danger of being shocked and defected.
Analog meters give much better, closer to true, readings in wider frequency range and other than pure sinusoidal waves.

The error can be quite big. For example, I did some comparisons, where a digital meter (same model as in your video) was showing 0,01 A but in fact it was 0,1A (confirmed by oscilloscope) of alternative current reading. Then I changed to an analog meter it showed 0,11A.
Or the digital meter was jumping from 14 to 140 V but on the analog volt meter was around 13 V.
I have an old analog meter LAVO3 (made in Poland in 70ties), it cost olny 1,5 euro, it is accurate by ~3% for sinusoidal waves up to 100 kHz. My FLUKE87 become unreliable at this frequency
I have check many old (over 30 or 40 years old) meters, they are still doing wonderful job. Get them if you have a chance.

[sucahyo]

When you want to see the true voltage or current, don't use digital meters if you are measuring something that is not pure DC or regular sin wave in range outside of ~40 to 200 Hz.

Thank you, never though the difference would be that big. I just measured it with analog and it's true that it only give half of previous. It show a little more than 200V.

There is little difference of current reading with DMM and AMM though. Using 300ohm base resistor it read 0.24A with digital and has around this number with analog. I can't measure 100ohm base resistor though, since in the digital it measured as 0.4A and my analog only have 0-250mA range max.

[denfyske]

banki waste spark circuit

Here is the Les Banki circuit intended for the Bob Boyce toroid. The circuit is for around 42 KHz, 21 kHz and 10 kHz but you asked for a fast switching circuit, the mosfet driver part and the fets. That can be connected to any oscillator and you apparently should use the 3 same frequencies.
The TC4420 is a 6a high speed mosfet driver with rise and fall times of 25nsec!. That means if you feed it with an oscillator with a slow rise time like a 555 it will take that signal and convert it to one with a 25nsec rise time and it will switch the mosfet on fully.
You could use TL494`s for your 3 frequency inputs
These parts are cheaper and the driver’s pinout are the same as the ones bob uses.
As for the fets. Use IRF540n. Also cheap
The toriod tuns you can get on chapter10 of Patrick O kelly`s site. PJK book ( Bob Boyce )
Even Bob said that he thinks the future for his technology lies in electricity generation and not in hydrogen generation
I hope this is of any help

Les Banki starter kit!

where is the banki waste spark schematic, anyone???