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PC PSU into a Lab PSU

Things

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led.png


+5V to the 5V line on your PSU (Red), and the resistor side to ground (black) :)
 





LaZeRz

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Oh ok!

Thanks!

Im not that familiar with this whole PSU conversion business but I thought i'd give it a try :D
 

Asherz

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Oh ok!

Thanks!

Im not that familiar with this whole PSU conversion business but I thought i'd give it a try :D

Just so your 100% sure, if you are putting together the adjustable voltage circuit, you need to take the +12v (positive yellow I believe) wire and the black (ground) wire. Not the +12v and -12v, otherwise you'll end up with 0-24v but you'll only be able to draw the maximum current the -12V line allows which isn't very much.
 

LaZeRz

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Yeh, my common sense lead me to believe that :D

Does anyone know where I can get these parts for cheaper????

If only someone in the US would buy the parts of digikey and have me pay them back the price + shipping + a fee for helping me :D

But im sure that would be rare :p

Anyway, if I need some more money later on I might sell it. How much do you think a adj voltage PSU will fetch.

If someone can lead me too a good DMM for under 20 bucks (can be from DX) It would be much appreciated

THANKS!! :D

Btw Trevor, can you post a picture of your modded PSU up please?

I'm going to use a lm338 because it can take 5amps of current and use some heatsinking I got out of an old ps2 to HS it

I cant wait until xbox360's get old, then I will be able to take apart mine :p Although I might mod it in the meantime
 
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Things

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I did actually have an abox360 I ripped apart a while ago, but I think it's gone now :(


Try get some old computers maybe, the CPU heatsink should be more than enough.
 

LaZeRz

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Yeh I have a few CPU heatsinks but if I can find a project box to fit inside the PSU I will use the ps2 heatsinks cause they are slim

I moved the fan to the outside of the case to make some more room

The project box's shape would have to look something like this:

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Btw did that 360 you ripped apart die RROD style?
 
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LaZeRz

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Jib has very kindly agreed to buy me some parts of mouser and ship them to me and he game me a reccomendation for a different type of IC

its the LD1084 and it can handle 5amps of current and has a lower Voltage dropout then the lm338

So now im going to make an adjustable voltage circuit and make a few holes in the PSU's body for an instant 12v

Thanks everyone!
 

LaZeRz

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Ordered the parts from Jib and they should be here soon :D

I'l post back when its finished and I will also make a little tutorial...

i've decided to make a adjustable voltage PSU with constant 12v and 5v aswell...
 
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What does the resistor on the 5V rail do? I've used a PSU for a down and dirty quick supply for a non-sensitive 12V-powered device, but don't have a scope... Maybe does the resistor make the output voltages more stable or something?
 
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Without it, applying a load to other rails often causes it to cut-out.
Most of the older ones I've modified don't need one, though.
 
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Hmm, can't say I've ever experienced that either. Not that I get to play with many "newer" PSUs...
:thanks:
 

LaZeRz

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The parts arrived late last week...

excellently packed and fast shipping :) thanks Jib!

ejvb6h.jpg



5688g.jpg
 

LaZeRz

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I found this on your rep page: "None of your comments make any sense!"

I completely agree to that :rolleyes:
 

LaZeRz

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Hey guys, been really busy lately and I have hardly even done anything... Plus, i need a new soldering iron before I start.

Progress so far: Used some Artic Alumina to thermally bond everything together (resistor and IC)

33u2v15.jpg


2dax8ch.jpg


303bo7r.jpg


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Added some rubber grips to the base :p :

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Grouped together some 12v wires to put on a seperate binding post for running fans:

r09fcx.jpg


Will start soldering everything together when my new soldering iron arrives :)

Since im posting pics, might aswell post a macro of a Lpc-815 diode :D

35905j8.jpg
 
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Things

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What does the resistor on the 5V rail do? I've used a PSU for a down and dirty quick supply for a non-sensitive 12V-powered device, but don't have a scope... Maybe does the resistor make the output voltages more stable or something?

Usually they'll power up, but then cut off once the capacitors charge up. I'm not sure if it causes damage however - I suppose it could if your rails started floating too high.
 

LaZeRz

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Little update:

I went to Jaycar and bought a switch, a project box, some heatshrink and binding posts with banana plugs :)

DSC07306.jpg


DSC07307.jpg
 




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