Re: PC power supply conversion question

On Apr 16, 9:32am, Mike Benedict wrote:
> Subject: RE: PC power supply conversion question
> At 16:57 04/15/1999 -0700, you wrote:
>
> >As a general rule I like switchers for regulation and high-current in a
> >small space. I have run across some boards that don't like the
> >switchers start-up characteristics. (I think some switchers faster
> >start-up ramp causes latch-up on some boards. Sky Shark and Choplifter
> >have given me problems in particular...) The lack of a 5.0V adjust on
> >most switchers can be annoying, but by and large the benefits outweigh
> >the problems in my book.
>
> Sounds like a definite "your mileage may vary". :-)

Personally, I've had no luck in putting a switching power supply in ANY game
that wasn't JAMMA.

Tron: ended up causing an enormous amount of hum in the speaker line. The
original power supply board, after repaired, was nice and quiet.
Joust: caused "Factory settings restored" all the time. This still happens
with my Joust boardset in my JAMMA cabinet. Repairing the original Williams PS
is the way to go.
Defender: causes "bad ram" errors on first power up (powering down and up
againg fixes it), and sometimes starts up in test mode! Anyone have a Defender
PS board FS?

> I wonder if a healthy sized cap on the output of the switcher would slow
> down the up ramp sufficiently for the boards that latch up.
>
> >Vector games can be a little trickier because they tend to have "odd"
> >voltages present. I use surplus switchers with "big" outputs (like
> >+/-36V) and then use a little home-made linear regulator to get the
> >desired voltages. Most of my Vector stuff runs on original power still
> >though. (Easy to have a stack of ARII's around. ;-)
>
> Somebody mentioned using a switcher for the common voltages and leaving the
> rest of the supply intact on Sega vectors a while back. I'm thinking about
> giving this a try (sorry Mark :-)

Ah, I don't blame ya. After replacing my Eliminator 4-player power supply
twice (and believe me, it's just a tad cramped in there), I'm considering a
hardware upgrade myself. I'm avoiding it however, seeing as my other switching
power supply attempts have failed miserably. I'm just glad to have finally put
a power switch on my Eliminator (who was the genius at Sega who decided not to
put power switches on the cabinets?).

____________ ______ ___ _____ __ ____________
               / __/ / / / |/ / / |/ //|/|/|_______________
Mark Jenison / __/ /_/ / / / | // | / |__ __/ _ /__ \ Sega/Gremlin
jenison@ /___/___/_/_//_/_/_/|_//__|/__| / / / // / / Color Vector
cig.mot.com /_/|_| /_/ /____/_/|_| Arcade Games
____________ The One and Only 4-player vector game ____________
Received on Fri Apr 16 10:21:16 1999