HP 456A AC supply xfrmr ?

[Henry Kolesnik]

I need to find or build an AC supply for the HP 456A AC current probe. The
factory optional AC supply has B+ at 5.4 VDC at 5.5 ma, and the B- is 8.1
VDC at 20 microamps! (Mine has dead mercury batteirs that supplied 8.1 and
5.4) HP used a small centrer tapped transformer that shows 25 VDC on the
output of a 1/2 wave bridge( 2 1N38A diodes) that is regualted down to the
8.1 and 5.4. using a 2N650 pass transistor and a 14 volt zener(updates show
it at 6.8 v). I can't find anything on the physical size of the xfrmr but
it has to be no bigger than end of ones thumb, or maybe they used a wall
wart but I kind of doubt it. I've not had any experience with real small
low current xfmrs that take 115VAC to 20 or 30 VAC and would appreciated
any ideas on what to use. A wall wart would be my last resort. I'd like to
fit the xfmr in the current probe case which has space for something about
an inch tall.
tnx
hank wd5jfr

 

[Gilbert Mouget]

In article <1034do4hamhlg35@corp.supernews.com>,
dated Tue, 17 Feb 2004 09:45:05 -0600,
Henry Kolesnik, <wd5jfr@oklahoma.net> says...

A wall wart would be my last resort.

A wall wart would be much safer.


--
"You cannot move mountains if you believe them to be mountains.
You must think of them as collections of small stones,
Which can be moved one at a time, and then reassembled."
-- The Tao of Meow