Pulsed Bifilar Coil

[Peterae]

This was the first digital monostable i designed, it used 2 8bit banks of dip switches to set the delay and pulse width, i also built a little controller which plugged in place of the dip switches so i could sweep in nS with this board, that can be seen with the 7 seg display in the early videos above.
http://www.overunityresearch.com/index.php?action=dlattach;topic=217.0;attach=1209

you can see my typical fet driver circuit in this diagram, i always use a 18V regulator to supply the fet driver, i used MCP1406 & 1407 drivers as they turned out to be better than the TC4429 in the diagram.
http://www.overunityresearch.com/index.php?action=dlattach;topic=217.0;attach=1215

[Verpies]

To ensure the safety of expensive signal generators an isolated gate driver can be used.

Optos are too slow for this purpose but other companies make fast RF and capacitively isolated drivers - they are suitable for this purpose, too.

[Matt Watts]

Optos are too slow for this purpose but other companies make fast RF and capacitively isolated drivers - they are suitable for this purpose, too.

Thank you Verpies for the link.  I never knew such devices existed.  Coupled with DC/DC converters to keep the power rails isolated from transients, these capacitive isolators hold great promise for much higher frequency drive boards.

[Peterae]

Here's a schematic that shows the early setup for explosions/crackling
http://www.overunityresearch.com/index.php?action=dlattach;topic=31.0;attach=11221

Schematic of fet and driver used
http://www.overunityresearch.com/index.php?action=dlattach;topic=31.0;attach=11223

Video showing basic micro changing the dip switches and thus sweeping in 1nS steps
https://www.youtube.com/watch?v=Ub5XhPJ2Y3A#t=27

Video showing thin enamelled copper wire jumping around in the presence of a magnet, quiet a complex coil wind
https://www.youtube.com/watch?v=O8GgiEeH1W4

Some interesting tests and data
http://www.overunityresearch.com/index.php?topic=136.msg1090#msg1090

[muDped]

I'll echo Matt Watts thanks to Verpies as well!

The Low Power Design page has a link to their numerous
Articles which is indeed a Treasure Trove of Technical
Gems!

A Seeker of Knowledge could spend hours, if not
days, studying the various Design Articles on some
very interesting subjects.

There is also a list of White Papers which may be
read/downloaded following a short registration.

[Verpies]

Thank you Verpies for the link.  I never knew such devices existed.  Coupled with DC/DC converters to keep the power rails isolated from transients, these capacitive isolators hold great promise for much higher frequency drive boards.

Actually, for a while now, I've been working on a universal MOSFET driver based on these devices and DC-DC converters, for the CARA circuit and its synchronous rectification.

[Matt Watts]

Actually, for a while now, I've been working on a universal MOSFET driver based on these devices and DC-DC converters, for the CARA circuit and its synchronous rectification.

Hopefully you saw my attempt of a universal driver.  With your help I'd be happy to upgrade this to something everyone can take advantage of.  Probably use some sort of pluggable MOSFET arrangement for driving whatever load is needed.  May need to think about how best to drive something like SIC MOSFETs that pull the gate below zero.

[lost_bro]

Hopefully you saw my attempt of a universal driver.  With your help I'd be happy to upgrade this to something everyone can take advantage of.  Probably use some sort of pluggable MOSFET arrangement for driving whatever load is needed.  May need to think about how best to drive something like SIC MOSFETs that pull the gate below zero.

Good day All
Couldn't resist posting some pic.s of my SiC_Pack.  It is designed to pulse Six Cree C2M0080120D mosfets in Series.  This is the equivalent of a 7kV2 switch, with complete galvanic isolation (GDT with 12kV2 30awg magnet wire).
Still in testing phase, but working extremely well. Have attached some scope shots as well.  This was primarily designed for nano-second pulsing, but as you can see it will (with the appropriate GDT) produce a clean 50% duty cycle as well (30ns rise/fall times at the gate).
Generally I can obtain <1ns skew between channels (mosfets) at anywhere from a 50kHz to over 2MHz range.
I am currently using an Arduino based signal generator which interfaces with a hardware hacked AD9850 dds. The hardware hack allows for control of the duty cycle of the AD9850 dds by the arduino as well.
The gate signal floats a -4 to +20 volt signal. The positive offset is adjustable on the fly and the negative offset is part of the design (must change out components to modify).
This was designed as part of another project which requires HV nano-second pulses.

take care, peace
lost_bro

[Peterae]

Very impressive lost_bro