My name is Robin Öberg. I live in Falun / Sweden and I’m currently trying to turn some old C64:s into a masterpiece.  ;)
I’ve just completed my first veroboard-circuit trying to get the optimized C64 PSU-thing working. Everything seems ok and the LED lights up just fine. The thing is though that I get 18,1 V DC instead of the 14 V I wanted. The LEDport reads 5,2 V DC as does the other port. I’ve checked everything and I think I’ve succeded in copying Torsten´s design to veroboard. Any ideas where I could have misplaced something would be of great value. Thanks!
I’ve included some pictures, but since the construction is kind of messy I’m not sure if they are of any help.
Left view, capacitators marked.
Right view, capacitators marked.
Top view, voltages marked.
Edit: My recycled PSU gives me 5,2 V DC and 10,5 V AC (instead of 9) - could that explain it?
My name is Robin Öberg. I live in Falun / Sweden and I’m currently trying to turn some old C64:s into a masterpiece.  ;)
I’ve just completed my first veroboard-circuit trying to get the optimized C64 PSU-thing working. Everything seems ok and the LED lights up just fine. The thing is though that I get 18,1 V DC instead of the 14 V I wanted. The LEDport reads 5,2 V DC as does the other port. I’ve checked everything and I think I’ve succeded in copying Torsten´s design to veroboard. Any ideas where I could have misplaced something would be of great value. Thanks!
I’ve included some pictures, but since the construction is kind of messy I’m not sure if they are of any help.
Left view, capacitators marked.
Right view, capacitators marked.
Top view, voltages marked.
Edit: My recycled PSU gives me 5,2 V DC and 10,5 V AC (instead of 9) - could that explain it?
The pictures are colorful and all - but not that helpful I guess. :-[
I’m using a “78L09” regulator and the rectifier is a “B40C800DIP”. The 18 volts are measured “as is/unloaded”. I’ll measure again using a resistor when I get home. Thanks!
The pictures are colorful and all - but not that helpful I guess. :-[
I’m using a “78L09” regulator and the rectifier is a “B40C800DIP”. The 18 volts are measured “as is/unloaded”. I’ll measure again using a resistor when I get home. Thanks!
Little thing: The SID needs 12 Volt @ very low current. So it should be no prob to get the 18 Volt down to 12 or 9 Volt without to much heat (heatsink really not needed!).
So, if you can´t find any solution, just forget it right now and go on.
And: 10 kOhm @ 18 Volt is not really a “Load”: That´s just 1,8 mA…
The voltage will go down with some more current (@ about 50 mA) for sure.
Little thing: The SID needs 12 Volt @ very low current. So it should be no prob to get the 18 Volt down to 12 or 9 Volt without to much heat (heatsink really not needed!).
So, if you can´t find any solution, just forget it right now and go on.
And: 10 kOhm @ 18 Volt is not really a “Load”: That´s just 1,8 mA…
The voltage will go down with some more current (@ about 50 mA) for sure.
I’ve gone through the veroboard again, and when measuring with a 10k load the voltages read 17,7.
The ground pin of the 78L09 seems connected alright and measuring on the regulator pins gives me
leg 1 to leg 2 13,4 V
leg 3 to leg 2 12,8 V
When measuring from + on the bridge-rectifier to ground I get the same 18 volts - but when measuring from + to - (both on the rectifier) I get 13,4 V. Does that seem ok?
[pay_c]: Ok, so I’ll just stick with my 18v and let the regulators on the SID-module do the work?
I’ve gone through the veroboard again, and when measuring with a 10k load the voltages read 17,7.
The ground pin of the 78L09 seems connected alright and measuring on the regulator pins gives me
leg 1 to leg 2 13,4 V
leg 3 to leg 2 12,8 V
When measuring from + on the bridge-rectifier to ground I get the same 18 volts - but when measuring from + to - (both on the rectifier) I get 13,4 V. Does that seem ok?
[pay_c]: Ok, so I’ll just stick with my 18v and let the regulators on the SID-module do the work?