On Sat, 12 Jun 2010 10:20:10 -0700, PlainBill47 ǝʇoɹʍ:

On Sat, 12 Jun 2010 10:32:04 -0400, "tm" wrote:


"JW" wrote in message
. ..

Nice price. I'm working on a 1KW HP 6032A power supply (with outputs
unloaded in this case, so I don't need *too* much current capability)
and need to connect my scope to the hot side of a switching
transformer - specifically the source and drains on the output FETs.

Service manual: (3MB)
http://www.home.agilent.com/agilent/redirector.jspx?
action=ref&cname=AGILENT_EDITORIAL&ckey=1000000384-1%3Aepsg%
3Aman&lc=eng&cc=US&nfr=-35687.384731
Page 113 shows the schematic of the FET board.

With an isolation transformer, I *think* I would connect the scopes
GND lead the source of Q1 and probe the it's gate to check the it,
then move the scopes GND lead to Q3's drain lead to check it's gate
drive.

Given that, would that Ebay transformer be the right choice, and do I
need to isolate (disconnect) the ground on the 6032A power supply
under repair?

Thanks.

This is a "bad idea". Better to use a differential input and two
probes. Do you have a two channel scope with invert on channel 2?

Tom


That would be news to large numbers of electronics technicians who had
to use an isolation transformer when servicing TVs and other 'live
chassis' consumer electronics. There IS a reason the advice was 'to
always keep one hand in your pocket'.

PlainBill

Serviced many GE VIR portables with a Sencore PR57 Powerite.