3 Sep
2014
3 Sep
'14
3:59 p.m.
Chuck,
This box was upgraded to the 'B' supply - so it has one very large xfmr in
it, with three secondaries. The +8V line is rectified by a 35A part, into a
95,000uF computer-grade cap.
The +/-18V lines use a modern bridge, and 4400uF of new low-ESR filter caps
at the inputs. Regulation is by new LM7818 / 7918 1.5A regs, w/heat sinks,
and 22uF + 0.47uF (film) bypass at the outputs.
So it's about as modernized as it's gonna get, while still using the legacy
transformer.. you still consider that under-rated?
On Wed, Sep 3, 2014 at 4:53 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 09/03/2014 02:05 PM, drlegendre . wrote:
There is no AC mains-side bypass installed, of any type - nor is any shown
in the schematics. It probably won't hurt to
install an X-type across the
line, though.. seems like the sort of thing it ought to have, eh?
It probably wouldn't hurt to cut down on some RFI. That baeing said, is
your chassis connected to the line safety ground? (that is, is the ground
lead in your line cord firmly connected to the chassis? It is on my
8800). If you wanted to use a made-for-purpose unit, you could use one of
the packaged "bathtub"-style AC line filters.
I can mount one, once I decide what to do - if anything - to limit the
inrush current. From the data, it seems like the
CL-60 might be the ticket
for this one.
The original 8800 supply is a piece of under-capacity slapdash design,
IMO. There are many better designs. My S100 Integrand box has a power
transformer that you could probably arc-weld with.
--Chuck