21 May
2012
21 May
'12
9:55 a.m.
On Mon, 21 May 2012, Camiel Vanderhoeven wrote:
I am not famaliar with the electrical properties that define what kind of
capacitor is used in which situation, so I wasn't sure if this was
acceptable or not.
I am curious, now, as to why they used this glass-encased "metallised
paper" capacitor instead of, say, an electrolytic. There are many
electrolytics inside the PSU, so it clearly wasn't a lack of availability.
Presumably there was a specific reason they chose this type of cap over
another. I'd hate to be wrong and do worse damage.
- JP
I received a
new (to me) MicroPDP11/23 that I was fiddling about with over
the weekend. After
testing out the supply voltages, and then putting the
system together enough to get serial out of it, there was a pop, a whoosh
and a rather exciting ejected ?> plume of smoke from one of the upper fans.
These seem to blow/burst often. I believe the cap is there only to limit RFI
emissions, so you can leave it out safely. The power supply should run fine
without it. If you do need to replace it, I wouldn't replace it with the
exact same type, but with a later cap less prone to blow. Any 250V 220nF cap
should do just fine.