Using a MOSFET with Peltier

Hi everyone,

I'd like some feedback on the attached design. The purpose is to power a peltier chip, via the n-Channel MOSFET, but I want to make sure I don't mess up the wiring and damage my Arduino board. Am I missing any components, maybe a diode between the + and - on the peltier chip incase it generates a current while the system is off?

Here are a few points:

• I have a 14.8V input
• IC2 is a 6V regulator, which powers the Arduino board
• The peltier chip must receive 14.8 V @ 2A - 7A (or there about)

Thanks,
Justin

Peltier Sketch_schem.png2454×1671 159 KB

There's no resistor to the gate of the fet or pull down.

I'm more experienced with bjt, but current flowing out of the peltier should be blocked by thr fet?

How often are you turning on and off the Peltier device?

The Peltier device will not produce enough voltage to do any harm the the MOSFET.

If your only turning the device on an off once in a while (to maintain a temperature) your diagram looks fine. Just make sure the Peltier device is thermally connected properly. They can not withstand high internal temperatures.

•IC2 is a 6V regulator

Add a 100nF input capacitor to the regulator.

I would use a lm317 adjustable regulator set for 9Volts.

LarryD:

•IC2 is a 6V regulator

Add a 100nF input capacitor to the regulator.

I would use a lm317 adjustable regulator set for 9Volts.
Department of Electrical Engineering - University at Buffalo

Thank you for everyone for your replies,
I'm making a camping fridge and have a heat sink on it.
The software will turn it on and off based on the temperature - so not often (or in short time).

I forgot about the resistor blush.

I already have a regulator for the arduino board that works @ 6v.

Will try replace my relay with the mosfet and let you know the out come.
Hope you can see the pics, here they are https://www.facebook.com/JGPorteous/media_set?set=a.10151595122916625.1073741827.587021624&type=3

thanks again,
Justin