On Fri, 16 Apr 1999, jason Milsom wrote:
> I also have a Tron and Discs of Tron both running on switchers. The
> trick there is to use the Switcher for the 5v and leave the original PS
> for the 12v. I had the same trouble with the loud audio hum when using a
> switcher for everthing.
Why bother with the switcher, then? Linear supplies are among the
easiest things to fix, and you're not getting rid of it anyway, so why put
the switcher in there?
> There is one other benefit from using a switching supply. Some games
> (especially Williams ) have a fairly good chance of taking out parts on
> the boards when the Power Supplys fail. The 5v may go up to 8-12v.
> Switching supplies won't do this. This happened to me on my StarGate,
> and I've heard of this from other people.
The Williams fix is a no-brainer. If you're worried about the
+12 rising when the 2N3055 fails, put a 12.6V Zener on the output. I
never had this happen on the +5V rail, but you can do the same thing.
I'm not sure if there was actually any sort of service bulletin about
this, but it's easier than putting in a switcher. If you want to get
fancy, you can put an LED in series with the Zener to light up when the
Zener is regulating the voltage (which it shouldn't be doing.)
Joe
Received on Fri Apr 16 11:02:24 1999
This archive was generated by hypermail 2.1.8 : Thu Jul 31 2003 - 23:00:45 EDT