If you find yourself having to troubleshoot electronics and always searching for a spare charged 12 volt battery like I used to, this should be useful. The idea is simple, a CPU runs on DC, but the electricity coming from wall outlets is AC. All a CPU power supply does is convert and step down that voltage. The first step is getting your hands on an old power supply. Any CPU that you find on the side of the road will probably work, unless of course someone is throwing it out because they didn't know how to replace a bad power supply.
Here is a link:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
If you have worked in a lab environment, you may be shocked at the price paid for power supplies. The difference is that lab power supplies provide a "cleaner" signal. For most power tools, car electronics, etc, you don't need to have a signal this refined, so a CPU power supply is perfect.
I have been asked if you could use these to charge automotive and marine batteries. While I don't see a problem with it, this type of power supply isn't really made to handle the amount of amps that these batteries will try to pull out of it. Read the back of the PS and it will tell you the output amperage at 12 volts. One of the ones I use is a 200 watt power supply, but the label says it outputs 10 amps at 12 volts.
Rearrange: P = V * I to P / V = I then (200 watts) / (12 volts) = 16.7 amps
So the answer is don't do math, just go by the output number on the back. Manufacturer's ratings can be exaggerated and there are losses in conversion.
Wiring a few of these in parallel will provide more amperage, but I am not curious enough to try it. Most power supplies have overheat protection, so it would probably just take a long time to charge or maybe it would burn it out.
Here is a link:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
If you have worked in a lab environment, you may be shocked at the price paid for power supplies. The difference is that lab power supplies provide a "cleaner" signal. For most power tools, car electronics, etc, you don't need to have a signal this refined, so a CPU power supply is perfect.
I have been asked if you could use these to charge automotive and marine batteries. While I don't see a problem with it, this type of power supply isn't really made to handle the amount of amps that these batteries will try to pull out of it. Read the back of the PS and it will tell you the output amperage at 12 volts. One of the ones I use is a 200 watt power supply, but the label says it outputs 10 amps at 12 volts.
Rearrange: P = V * I to P / V = I then (200 watts) / (12 volts) = 16.7 amps
So the answer is don't do math, just go by the output number on the back. Manufacturer's ratings can be exaggerated and there are losses in conversion.
Wiring a few of these in parallel will provide more amperage, but I am not curious enough to try it. Most power supplies have overheat protection, so it would probably just take a long time to charge or maybe it would burn it out.
My favorite application of this I have found for this is the radio that I have in my garage. I took an old double din DVD receiver and 6x9's and mounted them from the rafters of the loft. The receiver has a remote control, bluetooth and a bunch of other options so you are only limited by your imagination.