Re: Differential voltage probes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

I just remembered hewlett-packard (I think) make a 'linear optocoupler' 
which is like an ordinary optocoupler but with 1 LED and 2 isolated 
photodiodes. You use one photodiode for feedback stabilization and the 
other for output.

You can use one of these plus two op-amps to make an opto-isolated scope 
probe with about 1MHz bandwidth. This approach would probably give better 
performance when looking at small signals like gate voltages etc.

Agilent part# HCNR200
http://literature.agilent-dot-com/litweb/pdf/5988-4104EN.pdf


>At 18:28 27/06/03 -0600, you wrote:
>>Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
>>
>>Hi All,
>>
>>Finn and I have been thinking about differential voltage probes that 
>>would be useful for solid state Tesla coil work.  Rather than spend $$$$ 
>>on commercial ones, say from Tek, we were wondering about just making our own.