I'm back again with my amateur questions (-:
I'm going to be hooking up a peltier to my arduino through a power transistor (the peltier pulls 1.2A at 5v (!)).
As you may or may not know, a Peltier cools on one side and heats the other, creating a temperature difference between the two. I've got heat sinks and fans all worked out, etc. When the polarity is reversed, the heating and cooling sides are inversed, as well.
In the default configuration, the peltier will be a cooling device (cold on the inside of my cooling chamber, and hot on the outside). This part is relatively simple.
However, I'd like to be able to reverse the polarity of the peltier, electronically (by either lighting up a 2nd pin on the arduino, or by perhaps turning the pin off). I have no idea how to do this electronically. Is there a device that I've never heard of that does this? Would I need to use a dpdt relay or similar?
My power supply can deliver +5v and also +7v (+5v -> +12v).. not sure what 7v would do to the thermistor, but maybe I can buffer it with an appropriate resistor or something.
In any case... ideas?