Power supply issues

Post by **marshallh** » Sat Sep 10, 2005 2:22 pm

Hi all, I'm in the process of making a n64p and so far, I've got it to run off of 8AAs in series. They are 2300mah Ni-mh batteries, so they should last quite a while.. right?

I'm using a Sony cigarette lighter adaptor, and it regulates to exactly 3.3v! The system worked great fior about 20mins, then all sorts of noise and flickering started. I knew immediately, this is a power suply problem. I hooked it up to a 12vdc lead-acid battery, no problems there. The 8 AA's added up to about 10 volts, shouldn't this be plenty for the 7805 on the mobo? The Sony regulator still puts out 3.3v under load.

This is puzzling me, any suggestions?

Post by **Triton** » Sat Sep 10, 2005 2:47 pm

waht is the amperage output for the adapter? the 3.3v line needs 1.5 amps i think

Post by **marshallh** » Sat Sep 10, 2005 6:11 pm

The ps is rated for 1 Amp at 6v, so thats 6w, so possibly it supports 2 amps at 3v?

The 3.3 supply seems to be working just fine with the lead acid battery. Maybe the ~10v of the Ni-mh batteris are too low for the regulator.

Post by **Triton** » Sat Sep 10, 2005 6:46 pm

the 12v line should run fine as low as 7.2v at about 500mah, so im not sure

Post by **Gamelver** » Sat Sep 10, 2005 7:05 pm

more like....117ma

and the 3.3V line is 1.2A to 1.5A (not Ah or mAh

)

Post by **gannon** » Sat Sep 10, 2005 7:58 pm

last time I checked it was 500mA on the 5V line, although that most likely depends on the game since it only powers the gpu IIRC

Post by **Gamelver** » Sat Sep 10, 2005 8:21 pm

500mA on the 5V line or on the 7.2V+ line?

on the games that I tested, it was 117ish mA for all the games on the 7.2V+ line...

Post by **gannon** » Sat Sep 10, 2005 8:27 pm

on the 7.2V line. I was running starfox IIRC

Post by **Gamelver** » Sat Sep 10, 2005 8:28 pm

ah.....well then, I guess it does vary....