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Using a Commodore64 PSU for the Dragon

Posted: Tue Oct 03, 2023 2:29 pm
by Jackb01
About a year ago I bought a Dragon64 without a PSU. I build an AC PSU myself with 2 transformers providing the 9V and 2*18V AC, but that was too big and unpractical. I know there are modern alternatives for replacing a Dragon PSU, but I wanted to keep everything as much orginal as possible. So I came up with a solution using an C64 PSU.

I am using 9V AC from that C64 PSU and a little adapter cable from DIN to DSUB9 to connect it to the Dragon. This is used to generate the 5V using the orginal Dragon PSU board. The +12V/-12V are generated using a DC-DC Boost Buck Converter with that 5V as input.
I cut the traces from the +12V/-12V near the PCB connector on the PSU PCB and soldered the +12V/-12V from the DC-DC Boost Buck Converter directly on that connector. I all fits inside the Dragon because I removed the RF-modulator.

The DC-DC Boost Buck Converter is this one: https://a.co/d/fOgiUwj

I've been using this solution for a couple of weeks and it all works without a problem. I use the Dragon with a CoCoSDC and for the video output a RGBtoHDMI which is connected using a mini-DIN through the former RF-modulator hole.

See the pictures for more details.

I am new to this forum, so maybe someone else already came up with the same solution, but I thought I'd share it anyway.

Re: Using a Commodore64 PSU for the Dragon

Posted: Wed Oct 04, 2023 6:50 pm
by robcfg
Hi, and welcome to the Dragon Archive!

That is a nice solution for solving your need for a cpu, and it's as good as any other :mrgreen:

I added a switched-mode power supply internally as I prefer to have everything together and not forget anything, nor having to look around for all the bits and pieces.

Thanks for the nice pictures!

Cheers,
Rob

Re: Using a Commodore64 PSU for the Dragon

Posted: Sat Oct 07, 2023 10:34 pm
by wayland
I like this solution because it should still be possible to use the original Dragon PSU.
I have wondered if you fed the DE9 plug with the correct DC voltages would that work?