Re: c64 / vic 20 power supply replacement

From: didier derny <didier_at_aida.org>
Date: Fri, 28 Oct 2016 21:23:46 +0200
Message-ID: <3af2fec3-80d6-c1d1-24c6-8fc2d76febf5@aida.org>
any magic trick to remove the rectifier and capacitor ?

I opened 2 power supply   1 for c64 (round connector) and 1 for plus4  
(square connector)

the one for c64 the 7805 is glued at the bottom in something really 
hard.... seems out of reach

it seems impossible to remove the pcb without breaking something...

on the one for plus4 it seems possible to cut the 7805 leg and to remove 
the pcb...


I'll try your solution on the plus4 power supply

thanks


On 28/10/2016 20:47, Gerrit Heitsch wrote:
> 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.
>
>  Gerrit
>
>
>
>
>
>       Message was sent through the cbm-hackers mailing list


       Message was sent through the cbm-hackers mailing list
Received on 2016-10-28 20:00:21

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