Path: utzoo!attcan!uunet!lll-winken!oodis01!figueroa
From: figueroa@oodis01.ARPA (Andrew Figueroa)
Newsgroups: comp.sys.cbm
Subject: Homemade Power Supply (was: Ambitious RAM Expansion Hacking)
Summary: Is it really enough?
Message-ID: <145@oodis01.ARPA>
Date: 24 Jan 89 17:55:38 GMT
References: <1287.23DA03C5@isishq.FIDONET.ORG> <531@csd4.milw.wisc.edu>
Reply-To: figueroa@oodis01.ARPA (Andrew Figueroa)
Organization: Ogden Air Logistics Center, Utah
Lines: 28


All the references to "beefier power supplys" make me ask about my own recent
project.

I built a C-64 P/S from a "Power-One" HB5-3/OVP-A 3 amp DC power supply (this
is regulated with overvoltage protection).  I wanted to get 9 VAC off of the
transformer secondary leads but I could not get that to work.

I needed a 9V 1 Amp transformer to complete the project but only found a 9V .5
Amp transformer to complete the kit.  My review of the C-64 schematics and
references in the C-64 Programmers Reference Guide led me to believe that .5
Amp is enough.

I rounded the "kit" out with a 1 Amp fuse on the inbound 120 VAC and topped it
off with a 230V 5" muffin fan (the 230V fan runs slowly enough to be totally
quiet yet provide for very COOL operation.

I've run this outfit for many hours without any problems.

Any ideas that I may get into power insufficiency trouble with this homemade
effort?  Think it will drive an REU without going up in smoke?

(disclaimer - "Kids, don't try this at home.  You may burn yourself with the
soldering iron, burn the house down, or destroy your computer, yourself, or a
friend."  I don't know how these things work - I just put them together!)

Andy Figueroa
aka "figueroa@wpdis01.arpa"