Amperage for the PCjr. Bigger PSU.

General discussions on the PCjr

Amperage for the PCjr. Bigger PSU.

Postby riq » Wed Feb 21, 2018 8:14 am

Hi,

My understanding is that PCjr PSU delivers ~4 amps (75 / 17.7).
Without the JR-IDE + DOM, and the external floppy drive, how many amps are "left" ?


I recently installed a JR-IDE with a DOM. The DOM takes current from the JR-IDE itself.
The computer also has an external 3.5" floppy drive, taking also current from the PCjr.

And my guess (without doing any math) is that I will need more amps... but I would like to know how many "amps" are left, and also, if someone builds PSU with bigger amps.

Thanks!
riq
 
Posts: 36
Joined: Sat Dec 09, 2017 2:36 pm

Re: Amperage for the PCjr. Bigger PSU.

Postby Brutman » Wed Feb 21, 2018 8:19 am

I'm too lazy to look up the conversions but normally the power supply cards are rated in watts. The short card is something like 33 watts and the long card is something like 45 watts. And of course the problem with all of this is, at what voltage? There are two or three voltages levels running around.

Alan can speak better to the power draw on the jrIDE but I don't think it's a crazy high number, and the Disk On Module takes almost nothing to run. A PCjr with the short card should be able to power a jrIDE and an external 3.5" floppy drive; remember, you probably are not spinning both the internal drive and the external drive at the same time. I always use a power sidecar for extra margin, but I also have a parallel port and sometimes a speech adapter on my system.


Mike
Brutman
Site Admin
 
Posts: 930
Joined: Sat Jun 21, 2008 5:03 pm

Re: Amperage for the PCjr. Bigger PSU.

Postby riq » Wed Feb 21, 2018 9:06 pm

Thanks!
riq
 
Posts: 36
Joined: Sat Dec 09, 2017 2:36 pm


Return to PCjr General Discussion

Who is online

Users browsing this forum: Majestic-12 [Bot] and 2 guests