Re: c64 / vic 20 power supply replacement

From: Gerrit Heitsch <>
Date: Fri, 28 Oct 2016 20:47:37 +0200
Message-ID: <>
On 10/28/2016 08:35 PM, Jim Brain wrote:
> On 10/28/2016 2:37 AM, Didier Derny wrote:
>> Hi
>> Is there any existing replacement for c64 power supply ?
>> I have 2, one with round connector for c64 / vic 2 and one with square
>> connector for plus4
>> both are heating like hell, in no time and have a really bad smell...
>> I found one replacement on ebay but apparently not working in
>> europe... I tried to contact the vendor but no answer...
>> I found some people using 2 power supply  5v from usb  and 9v ac from
>> an external 9v ac power supply
>> any way to produce the 9vac from  DC ?
>> there is the problem of galvanic isolation...
>> --
>> didier
>>       Message was sent through the cbm-hackers mailing list
> Bil Herd (who lurks here) came up with an idea for such an option, using
> 2 FETs, a small transformer, and a 5V PSU.  As he's stepped away from
> the effort, I am retooling it for a 12V switching PSU, which will
> provide both voltages from a single 12 volt source.  It'll have a small
> time source to generate either 50Hz or 60Hz AC, selectable via
> jumper/switch.
> Have not had time to work on it this year, but need to get it off my
> bench...

I found it easier to just open up the PSU, remove the rectifier, 
capacitor and 78S05 regulator. Then add a better rectifier, capacitor 
and a switching regulator. The latter you can get on a small PCB on ebay 
cheaply. I like the boards based on the MP1584.

 From the outside the result looks the same, the PSU no longer runs hot, 
you get the real 9V AC and, on the +5V, you get more than the 1.5A the 
old PSU gave you.


       Message was sent through the cbm-hackers mailing list
Received on 2016-10-28 19:01:15

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