Need some electrical advice

Is there anyway to use this old computer parts to run my 12 v fans from that computer. I powered it up but fans didn’t run when I connected there wires.

You can also get a 12V DC converter and run the fans with out the computer at all. Fans should be labeled with the proper miliamps requirement. You can exceed it, but it shortens life a little. Hope this helps.

Yea, I’ll have to look around for old chargers.

@Covertgrower I Found an old charger and got them hooked up. The small fan is pretty slow.

This is my first grow NL Autos, got started late and here in South Carolina I am limited to what I can give them. What all or any suggestions that you may have at this point you two up to optimize my yield and quality?


Only using miracle grow at this point bottom feeding

Outdoor grow

The pc power supply will need a jumper to across 2 of the pins to power up the fans. Should be fairly easy to find detailed directions from a Google search.

When using random power supplies, the output voltage will correlate to fan speed. So a 12 vdc output will spin a fan much faster than a 5vdc output. As far as loading them, I wouldn’t load them beyond rated output. So if a fan says .3 amps, then I’d make sure the power supply is at least .3 amps or 300 ma.

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like what dbrn32 said you need to find which two wires were the on/off switch and just attach the ends of the two and the power supply will turn off and on by unplugging it or running a timer, after that you need to find which wires are the + and - on the +12 side and them two wires are the ones that will run 1 fan now there is more then one set of two +12 so if running more then one fan then you need more then one set, if i had the power supply near me i could tell you exactly what wires go where and i have used old computer power supplies for many 12v apps like R/C battery charger power supply, i have one converted as a 12v source at my bench so i can power up 12v auto stuff and test it…if i had pics of the stickers or diagram on the side and one nice clean birds eye view so i can see the wire placement i may be able to help you out, and you need nothing else from the computer other then the power cable and maybe a switch so its does not turn on soon as you plug it in but if on a timer it wont matter about having the second switch…either post the pics i require or PM to me and i will help you out brother…ok

Happy growing

The power supply has to have the green wire on one of the connectors and the black wire next to it cut away from the connector and strip and touch the 2 wires together. There are several black wires so you may have to experiment until you find the right 2 wires. When you do, install an on/off switch on them. It will not shock you. These wires went to the computers power switch. Most computer power supplies can run 250 watts worth of 12v or max around 2 amps. The main drawback to using a computer power supply is that when you lose power, you have to cycle the on/off switch to get the power supply to turn back on. Hope this helps.

you do not need a on off switch to replace the one that the computer used if hes running a timer and wants the fans on when the timer comes one then just find right wires and attach them hell i will take a power supply and convert one just to how you that you dont need a switch for the power supply to run if running a timer i know i use old computer and electrical stuff to build weird shit all the time like my Speed controlled 120v fan setup i made for my 600hps Batwing hood, out of a fan and 2 wires for a microwave and then the power cord and speed control switch setup from a fired dremel and wired it and now i have the only air cooled bat wing shade i have seen i even made a thread in the Beginner light area go see, its a cool idea and cost me NOTHING

after looking at your pic of the power supply i seen that you cut off some of the wires you will need to convert that power supply so either its JUNK now or you need GOOD soldering skills or your needing another power supply, as the green hot wire is GONE, and why did you only leave the black and yellows as i would have not cut one wire till i knew what was needed but if you find another let me know i will take you threw it step by step if you wish

I used an old 12 v charger and hooked them up. I left the black because they were ground and I left the yellow because it said they were the 12 v supply on the board. … I tossed it anyhow and hooked them up another way. But thanks! I do want to try doing my own LEDs at some point tho.

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I have a thread on diy led. If you have questions feel free to post there or tag me. I’d be happy to help if I can.

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True. I forgot about timer. Pretty stupid for an electronic guy. The timer is the on/off.