Op 24-2-2011 20:58, Bernhard Kuemel schreef:
Hi rat!
I was given a Mc Crypt PA-5000 amplifyer with the two internal fuses
missing. Fast 2 A fuses were blown by power up only, probably by
charging the capacitors. Fast 7 A worked, but are probably overrated.
The AC current measured with a multimeter goes up to 3.7 A peak during
strong deep basses. I read the unit is prone to dying (domed or leaking
capacitors) under high load so maybe 4 A fuses are still too high and a
more protective slow 3 A fuses may be sensible. What do you think? Which
rating are the original fuses?
Thanks, Bernhard
Here (
http://www.mikrocontroller.net/topic/144407) is a discussion in
German about the same amplifier. Schematics and board layouts are
included in that thread.
(side note: in his case R65 on the 4th page of the schematic was blown,
pls. note how Mc Crypt designed a 14V power supply from the 65V rail
voltage......)
YMMV, FF