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zeropage
October 28th, 2008, 02:07 PM
I got my hands on a Vic-20, older style with 2 prong power supply connector.

I know its 9 Volt AC but does anyone know how many amps are required?

I've seen pages that state its output is 18 Watts, so my guess is 2 amp.

Can anyone verify this.

Also is it possible to use a 5 volt pc type power supply and directly connect it to the 5 volt line and ground, by-passing the voltage regulator circuitry?

Many thanks.

wmmullaney
October 28th, 2008, 02:15 PM
I'd say give it 2 amps to be sure. You can bypass the regulator, if you have a good regulated 5v supply.

chuckcmagee
October 28th, 2008, 02:27 PM
Just looked at mine.

10 VAC 30VA, aka 3 amps.

carlsson
October 28th, 2008, 02:41 PM
Yes, the US version seems to be 10 VAC 30VA while the European one is 9 VAC 27VA.

As for your question, some people have modified their two-prong VICs to take a regular DIN-style power supply. While it only delivers 9 VAC 1A instead of 3A, most of the computer seems to run anyway. I don't know about 5V though. At least the user port outputs 9 VAC, but perhaps you don't have any peripherals for the user port.

zeropage
October 29th, 2008, 07:51 PM
Many thanks for the speedy replys :)

When I get a chance I'll use an AT power supply and using the 5v output connect it to the 5v rail of the Vic. I'll let you know how I fair.

Again many thanks guys.

Terry Yager
October 29th, 2008, 11:39 PM
Many thanks for the speedy replys :)

When I get a chance I'll use an AT power supply and using the 5v output connect it to the 5v rail of the Vic. I'll let you know how I fair.

Again many thanks guys.

Or you could ask me real nicely and I'll send you the real thing:

A-C Adaptor
VIC 20
Part No 902502-02
Input-117V 60 Hz 400MA
Output-11.5VAC 30VA

Was working a few months ago when I sent the board to tez.

--T

wiskow
December 3rd, 2008, 08:53 PM
This is quoted from Ray Carlsen's document on the VIC-20 (http://personalpages.tds.net/~rcarlsen/cbm/vic20.txt):

"Early version boards use a single 9VAC source
(transformer-only inside the power pack) at a rather hefty 2 Amps. The
rectifier, filter capacitors and regulator are inside the computer. You'll
see the large black metal heat sinks when you open it up."

channelmaniac
December 4th, 2008, 07:22 AM
Not only do you see the heat sinks but you'll find that one of them (the one on the rectifier) has a tendency to come loose and swivel around a bit if the computer is jarred - like falling off a desk.

If it gets too loose then the rectifier can overheat.

RJ