Re: Defender power supply requirements

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I've just hooked up the Switcher's +12 to the regulated and unregulated
12VDC on the MPU and audio.

Current draw is around 5 - 7 amps on the +5, 500ma on the +12, maybe 500ma
on the -5 ...almost anything will run it.

John :-#)#

At 12:39 AM 20/02/2003 -0800, Neil Bradley wrote:

> > I have used both computer and video game switching supplies with no
> > problems on my Williams games. No issues with corrupt memory - and 'if'
> > that is the case I would suspect that the power-up reset circuit on the MPU
> > is failing. After all CPU's all want about 2 - 500ms of RESET before going
> > 'live' and any switching supply worth it's salt will provide power in under
> > 100ms. So if you have a problem with memory corruption, then I would be
> > replacing any timing capacitors in the RESET circuit...
>
>Yeah, that has been my experience with all of the ATX switchers I've
>witnessed on a scope.
>
> > As far as I can see Williams made no effort for their supply to come up in
> > any particular order...they all boot at once.
>
>Well, there is this nasty resistor/transistor circuit that looks to
>qualify both the 5 volt rail and the 12 volt rail (at least) and it's
>connected to the system wide reset. So maybe the supply doesn't come up in
>any particular order, but the logic circuit definitely qualifies them
>both.
>
>So what do I connect the "12 volt unregulated" to on Defender? Just the
>+12 volt rail? All it appears to do is go to the big, nasty, evil
>resistor/transistor/zener circuit that controls reset.
>
>And I, of course, have purchased several ATX power supplies dirt cheap.
>Any recommendations on a specific wattage? I can't imagine it pulling more
>than a desktop PC.
>
>-->Neil
>
>-------------------------------------------------------------------------------
>Neil Bradley In the land of the blind, the one eyed man is not
>Synthcom Systems, Inc. king - he's a prisoner.
>ICQ #29402898
>
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Received on Thu Feb 20 09:40:28 2003