ok for voltage to be a bit high?

MIDIbox SID
1

Sorry if this is a dumb question but I’m a novice…

I’ve built the optimized C64 PSU on my prototype board and I notice that the voltage at the 5VDC output measures at 5.13VDC, and the voltage at the 14VDC output measures at 16.54 VDC.  I measured the AC coming out of the C64 power supply at 10.67 VAC.  Is it normal/OK for the voltages to be running a bit high, or is there a problem with my optimizer circuit or C64 power supply?

Thanks.

2

Hi,

5.13VDC should be Okay - it’s still in the limits (and who knows, how much your meter lies ;)). The PSU seems ok too.. But that 16.54 VDC is not good. I think I’ve got similar results when the regulator had input/output pins swapped..

Moebius

3

Good call…I did in fact have the regulator in backwards…oops.

After that, there was a short in the circuit which seemed to damage the C64 power supply…my 14VDC pin was reading 5.13, so I measured the AC coming out of the power brick and it was only 2.xxx AC!!  I had originally measured it at 10.67 VAC… in your opinion, could a short on the optimizer circuit have caused damage to the internals of the power brick?

Maybe the lesson to learn is that drinking beer and building electronics is not a good combo…

4

could a short on the optimizer circuit have caused damage to the internals of the power brick?

it could have blown the fuse of the PSU, but it can be easily exchanged

Best Regards, Thorsten.

5

I can’t seem to open the power brick…is there a trick to it?  Also, what fuse will I need?  Thanks!

6

Or did you mean I should just exchange for a new power supply?

7

Seems like you have “a new type” supply. Those are pretty damn difficult to open and then the inside is potted with epoxy.. better get a new PSU..

M

8

thank you both..now I just have to wait for the new psu to arrive…*sigh*

9

I killed my psu aswell. I builded the c64 optimized board. Once connected the led worked, but after a while it stopped. And now my PSU doens’t output any voltages :frowning: It’s not the fuse… Oh well, got another 3 psu’s on the way so ill figure it out :slight_smile:

Also can i connect the optimized psu board to the psu without connecting the core and sid? for testing the correct voltages?

10

Also can i connect the optimized psu board to the psu without connecting the core and sid? for testing the correct voltages?

Yes, Core and SID are not required to test the voltage.

11

stop hording all the power supplies!!!  >:(    :wink: