Otimized PSU blown fuse problem

MIDIbox SID
1

Hi Guys

Am trying to build the optimized psu at the mo using the online pdf and the http://www.danielprice.org.uk/synth-diy/sid_2.htm link

for info.

I am trying to test the circuit as i build it to make sure voltages are ok!

I used the power connector from a c64 and seem to have correct voltages on the board 5.16v dc and 10.2v ac.

However when i put the bridge rectifier in the circuit the fuse in my power supply blows?

I am using a W04M rectifier as the one specified isnt available from my local shop.

anyone any ideas why i might be having this problem?

4 fuses blown so far in testing  :frowning:

thanks… R

2

The pin arrangement on the bridge rectifier on that page is different to the ones I use, which has the “~” pins diagonally opposite each other, the “-” and “+” pins in the other corners. Perhaps yours is the same, and you’re connecting it wrong, which will short circuit between the AC inputs!

Use a multimeter to test the actual diodes in the bridge rectifier.

3

That rectifier should be well over spec, maybe test it with your multimeter to make sure it’s not a dud? Edit: Also what Wilba said :slight_smile:

Is this just the rectifier by itself, or is there other circuitry after that? If so, check for shorts…

4

I think Wilba may have it :slight_smile: The rectifier i have has the - and + diagonally so looks like i was creating a short circuit!

I’ll try again.

many thanks

R

5

yep that solved it  ;D Thanks Wilba!..

6

Wow, I didn’t realise that so many people actually looked at my page - I better get on with buildingthe rest of the damn thing! I’ll also update it with the info. about this problem, 'cause that’s liable to catch a few people out if they’re not expecting it…