Search found 3 matches

by sdf3sdf
Wed Dec 09, 2020 10:54 am
Forum: Voltage Regulators
Topic: PSU7 - intermittent operation in Commodore VIC20
Replies: 2
Views: 8414

Re: PSU7 - intermittent operation in Commodore VIC20

I added a push button switch that grounds the rectifier output via a 100Ω resistor - fixed! Now when I have to power-off/power-on (i.e. changing cartridge) I just hold the push button down for a few seconds after power-off. The VIC20, and PSU7, will then power-on again ... no more having to wait a f...
by sdf3sdf
Wed Dec 09, 2020 10:44 am
Forum: Voltage Regulators
Topic: PSU7 - intermittent operation in Commodore VIC20
Replies: 2
Views: 8414

Re: PSU7 - intermittent operation in Commodore VIC20

Discussed with Daniel via email: This is a "feature" of the PSU7. The reason is that the PSU7 want's to see the input and output at 0V (approximately) before it will start up normally. The PSU7 is designed for 24V operation and can withstand 28V if you are careful about spikes on the suppl...
by sdf3sdf
Tue Dec 08, 2020 7:47 pm
Forum: Voltage Regulators
Topic: PSU7 - intermittent operation in Commodore VIC20
Replies: 2
Views: 8414

PSU7 - intermittent operation in Commodore VIC20

I’m trying to use a PSU7 in place of an LM323K in an original Commodore VIC20 (two-prong power socket). Yeah, not sure why I got a bunch of PSU7s instead of PSU5s, but not sure if that would make a difference. The VIC20 receives a nominal 9VAC (around 10.2VAC when measured) which is then rectified (...