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Re: O-Scope for tesla coil use
Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
I think you mean like this:
See the files at:
Starting with "diffprobe".
Protecting the scope from faults is a big deal. See this one which is more
I would not bother trying to use other than a simple battery powered low
bandwidth TL082 circuit. I did manage to get the fast TI chip to sort of
work but it was a real mess. Not worth it... Best to keep it simple.
The problem is the high impedances at high voltage and high bandwidth
require compensations circuits that normal humans just can't figure
out. If it was easy, Tek would not get $1000+ for the darn
things... There are nice high sped op amps out there, but soldering in
countless little 1pF chips all over the place to pull the signals in is
just about impossible. You pretty much need the Tek probe to guide you
anyway. Then, the next time you try it everything is different so you
start from scratch again. Not repeatable at all... So if the simple
TL082 one will work, your all set, if you need like 50MHz stuff, you just
have to buy the darn things.
At 10:56 AM 3/23/2005, you wrote:
Back in 2003 you had a thread going about a differential wideband HF
amplifier based on the TL082 quad Jfet op-amp. I remember Malcolm
responding. I cannot find the thread now though. How did the project
turn out? Do you have a design/schematic?
A plug in differential amp for older tube scopes is cheaper, but confined
to that tube scope. A stand alone fet differential amp is much more
versatile, but much more $$$.
I have long felt a stand alone fet differental op-amp PCB would be a good
project. Maybe I can revive it.
Our higher voltage DC voltage regulator PCB is progressing. Hopefully,
I'll be able to post the schematic.