-
Member
running dual power supply
I'm interested in running dual power supplies but not in a redundant setup.
Is anyone aware of a circuit that can be attached to one of the power leads of an existing supply (maybe run inline with a drive power cable) so that it will switch the secondary unit on when power is applied?
Thanks
-
Senior Member
You can power a relay off of the 12 V output of the first powersupply and use it to close (short) the startup/turn on pins on the second powersupply (if it is an ATX). I have the pinouts of the powersupply connector here somewhere, if I can find it I'll post it.
-
http://www.sysopt.com/forum/attachme...&postid=633263
You will still need to connect an AC plug to the second PSU to power it when it is turned on by the first PSU, but thats no real problem...
-
Ultimate Member
-
Guest
You can do it as mentioned above, but why do you want to? Wouldn't it be just as good to get a higher output PSU. Just wondering
-
Ultimate Member
If not redundant, I am currious WHY not in parallel? Save buying all the relays or switching.
"Never corner something that's meaner than you are"
-
Senior Member
I preferr to isolate things like power supplies from one another. That way if one decides to exhale smoke the other is relatively safe.
Parallel should work just fine.
Relays are a couple of bucks at my local surplus store, & free at my friendly automotive junk yard.
Last edited by Happy Joe; 11-20-2003 at 09:27 PM.
-
Parallel=bad!
Never connect em in parallel. Each supply will have a slightly different voltage output. But when u connect em in parallel u force em to be at the same voltage. Because of the PSU's low output impedance, this can result in large currents. So dont do it. You'll fry both or cause them to turn off if they have good protection built in.
Do it the way it was first suggested. Get a 12v relay from radioshack and use one supply to short the green and gray (double check this, though im pretty sure) wires of the other.
-
Member
This is on a Dell system and the power supply is long and flat, not a standard unit I can pickup at CompUSA or the like
Thanks for the info all! Now I can get to the experimentin'
-
Senior Member
OlegB is correct...I was imprecise in my response (sorry). Connecting the two "turn on" wires in parallel shoud be OK. Connecting even powersupplies of the same model and brand in parrallel at their outputs is extremely risky.
-
Ultimate Member
When I referred to parallel, I was referring to parallel inputs, NOT output. Parallel inputs are virtually the same as series etc. and won't effect the outputs.
"Never corner something that's meaner than you are"
-
Senior Member
I understood, I merely wanted to emphasize the point for those people that only scan the thread instead of reading it in detail.
Enjoy!
-
Here's the reason I juggest using the relay instead of connecting the "turn on" wire in parallel: I don't know what current is drawn by this input and what current is provided by the motherboard. If it's a standard logic level signal that follows TTL standards or something similar, connecting up to 8 inputs from one output is not a problem. However, I dont have this info.
The relay is obviously more connections, but its a sure bet. If anyone has questions on the specifics of the relay scheme ask me and I'll be happy to draw some pictures and a schematic.
-
Ultimate Member
Since it is a Dell, I would be very very careful. I don't know if it's the case in your system, but Dell used to have the habit of installing powersupplies that had what looked like a standard ATX power supply and a radically different pinout. Needless to say it burnt a lot of boards and PSUs.
"Dude you're getting a Dell." Obscure curse from the early 21st Century, ascribed to a minor demon-spirit known as "Stephen?" [sp].
-
Member
Rugar is right
Every Dell,Gateway, even some Compaqs that I have ran into, have different pin-outs than a stock atx power supply
Be careful
chip55
I'm out of my mind..be back in 5 minutes! If I return before I get back, tell me to wait until I get there!
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
-
Forum Rules
|
|