Back to Basics

[darkspeed]

Here is that cross talk shot between the two IRF840's after i shut the sig gen off. There was a mosfet on both ends of the coil and the gates were connected with 24" of iron delay wire in the shape of a coil. Not sure where the power was coming from but it collapsed once it shocked me. This is a work in progress...

+Mosfet > coil >Mosfet-
5HZ square wave 10vp into gate of Mosfet- and through a delay line into +Mosfet
Mosfets were fed 20vdc
The coil was 16g copper wrapped vertically around a horizontal closed coil of 50 x 16g copper 10" dia.
I had been running for about 20 min with no effect then I killed the DC supply and in fooling with the connections i accidently disconnected the coil from the output of +Mosfet. When i snapped it back on the scope red lined so I switched over to 1:10, pushed the scale way down to 50ns and double checked that the DC was off. Then I killed the HP signal generator and the pulled the connector of the HP. The signal persisted for long enough for me to go and get my camera. When I picked up the loose sig gen line it felt all prickly and then the signal stopped. Restarting the system and no signal... must have reconnected +Mosfet at some special moment... Im guessing that 19.9mhz is as fast as those IRF840's can swing. It is a fairly sharp rise and fall. I should have a recording of it on that scopes hard drive.

[Grumpy]

I used this circuit:

I think the coax lines were short 3 ft or 6ft, so gap was overdriven.

[darkspeed]

I used this circuit:

I think the coax lines were short 3 ft or 6ft, so gap was overdriven.

Well thats an expensive book.. Edmund Miller

[darkspeed]

When I connected the delay line - (coiled bare steel wire) between the Mosfet gates I was actually creating an antenna effect. As the wave passed through the delay coil from the main coil it would send gate signal to the Mosfets thus switching on and one off just slightly out of phase. Seemed really clean and fast..

Might be worth playing with..

[Grumpy]

http://www.atis.org/peg/docs/peg2004/Petersen.pdf

see page 4

this explains the need for high self inductance

this explains the need for the cold transient

This explains why we do not use unmagnetized ferromagnetic cores for our coils and why the shock wave does not occur with these materials in the vicinity.

somewhere, far away, is the sound of a phone being answered:  several agents were just reassigned...LOL!