Pages: [1]   Go Down
Author Topic: Building a powersuply from an old computer psu  (Read 515 times)
0 Members and 1 Guest are viewing this topic.
Hyperspace
Offline Offline
Jr. Member
**
Karma: 0
Posts: 60
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

How hard would it be to add a low amperage 24V rail? I was thinking of a switch that would disconnect every other rail when ever you turned the 24V rail on. Max output is listed at 480 Watts.

I know that it's not arduino related, but it kinda is as this is to power my projects.
Logged

Never judge a man until you walk a mile in his shoes. But, by that time you're a mile away and you got his shoes, so screw em'

Offline Offline
Edison Member
*
Karma: 5
Posts: 1730
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If im getting thhe description right id say it would be hard to modify the psu for 24 v versus whichever voltage it is at because it was entirely designed for the original voltage, you would have to redesign it and change watever necessary
as fore disconnected rails either some mosfets or relays whould work
Logged

Hyperspace
Offline Offline
Jr. Member
**
Karma: 0
Posts: 60
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

That's why I asked. I was thinking it would be as easy as a voltage doubler on a 12V rail, but then I started thinking about some of the stuff you were saying. I was just trying to think of things i could do to it just for the experience of it, but I don't want to spend my time building shit, either. As it turns out, there is plenty to do just converting a computer psu to a benchtop powersupply. I have made one of these before from a cigar box, but it was just hacked together quick and dirty. I used it for quite a while and it never let me down, but this one is gonna be pretty nice.

I have one more power supply question, though. What is the proper polarity for the power cord? I don't see anything about c14 and polarity. I know it's really the device that will mind or not, but I want it wired the way it's supposed to be.

I said no more power supply questions, but I do have a mystery. I was just going to use my meter and check the cord, then it would be easy enough to tell how the male part should be. When I put my test leads in the end of the cord it blew the 8a250V fuse. I switched the positive lead over to the 10A jack before I did that, I usually don't. I can't help but think that had something to do with it. I felt a buzz as soon as I got both probes in there and I immediately snatched them back out, but it was too late. The cord works fine powering a tattoo machine powersupply, so I doubt the cord is faulty. I have never had that happen to me. Any advice what I did wrong?
Logged

Never judge a man until you walk a mile in his shoes. But, by that time you're a mile away and you got his shoes, so screw em'

Hyperspace
Offline Offline
Jr. Member
**
Karma: 0
Posts: 60
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I found a potential polarity candidate. I'll see what any of you guys come up with before I say.

Logged

Never judge a man until you walk a mile in his shoes. But, by that time you're a mile away and you got his shoes, so screw em'

Manchester (England England)
Offline Offline
Brattain Member
*****
Karma: 626
Posts: 34114
Solder is electric glue
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

It sounds like you had the meter on measuring amps and you put it across a voltage and shorted the whole thing out.
Logged

Offline Offline
Edison Member
*
Karma: 5
Posts: 1730
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

If the psu has both a positive and negative 12v rail then you already got 24v, althought if one rail has less capabilities than that's what you have to go by, say 12v 1 amp and -12v 100ma, you can only draw 100ma at 24v
Logged

Pages: [1]   Go Up
Jump to: