How do I drive a Peltier Cooling Plate with USB power?

I just ordered some of these 20mm x 20mm Peltier Cooling Plates and would like to power them with a USB hub.

Their rated at max of 4 amps and a max 3.8 volts and I know that generally USB is 5V and 500mA.

So I know I need to just reduce the voltage, but I'm not sure how to accomplish this.

I think I could drive them at 3.5V and still be okay, Not sure if I need a voltage regulator or if just resistors would do the trick.

Thank you

Kurt

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You don't drive a peltier element on a USB connection, period.

Run them at their rated current with a suitable power supply.
Even a high power USB port is rated to a max of 2A, so your elements won't do much as they can't get the power they need.

KurtRoesener (author)  Downunder35m2 years ago

Good to know, Thanks.

Nothing you can do to adequately power that particular peltier off USB. If you want to play around with a peltier on USB then get one made for it. This is a good option for about $20.

http://www.thinkgeek.com/product/96b3/?itm=customl...

If you want to use the one you have then find an old PC PSU. Use the 3.3V rail from it to power the Peltier and your good to go.

+1

at 500ma that cooler Mpilch linked to may not do too much, but it's the best your going to get for Usb

If you do build your own solution I would suggest you use a decent 5V power adapter and run it through a lm317 in *constant current mode*. Use the lm317 to limit the current to 3-4 Amps. The regulator has a natural 1.25V drop across it, bringing you down to 3.75v.

I have a few old hubs and routers that just so happen to have a 5v, 3A output. Perhaps you have something similar sitting in a box of cables !

KurtRoesener (author)  Wired_Mist2 years ago

Good point, I just might, I tend to save just about everything ;)

KurtRoesener (author)  mpilchfamily2 years ago

Okay, thanks for the link!

I do have extra PS units around, I was just trying to avoid extra outlets being taken up.