[?]Famicom Disk AC-Adaptor

i have here a FD AC-Adaptor in front of me which clearly declares a 9VDC output. but when i measure the voltage i get 13 Volts.

is that normal? don't think so but better ask before throwing it into the can

 

It's normal. The regulator in old consoles can handle a lot more than that so don't worry.

 

yeah..i know those old linear regulators (probably a 78xx) can burn a lot power dissipation, but from described 9V to 13V is a big gap imo, which i guess is anormal, resp. the AC-adaptor became faulty over the years (adjustement). unfortunately a can't open it, since they used kinda strange screws.

 

put a load on the output e.g. 12V rated bulb ... measure again ... i bet you get near the rated output

 

:redface: i'm getting old.

 

??? everyone does get old also its an AC adapter there is no 78xx in ... (that would be for DC) so the idlevoltage of the transformator is about 13 volt ... well suposed ok

 

no i mean, I'm getting old because i forgot about test it under load. that is what happens when you sit behind a desk. you forget things :redface:

and the 78xx was meant to be sitting inside the Famicom Disk of course

 

allright .. no problem for the 78xx to take the 13 volts then that are even more after the rectifier ... but its all about idleness

 

people forgetting that DC power supplies give a higher voltage if measured directly rather then having a load through them.

 

yes. as i said above i forget about things. during the last 10 years i mostly had to deal with switching power supplies, which do not show this characteristics of a normal coil transformer.