I am driving 2 peltier coolers using 1 pololu VNH3SP30 motor driver. In my system, it seems these coolers work best at about ~2.5amps each. Later on, I am going to introduce them to a larger system that is being run off of a 12V 30A power supply. While driving these coolers with PWM, the voltage and current being supplied jump around a lot.
The question: Since I am going to attach this to a 12V supply that is powering other subsystems, won't it mess with my supply voltage to those other systems? Should I use a voltage regulator or something and run the coolers off say 8V? (I say 8V because when I current limit my supply at ~4.9A, the voltage settles at ~8V).
I did some looking online, and it seems that people have been able to drive peltier coolers using motor drivers and PWM signals from an arduino of sorts. If you have done this, did you notice anything about the kind of power you were drawing? Ideally, I would be current controlling these with something like an LED driver, but nothing really supplies a high enough current for what I'm doing so I went with the motor drivers....
PS, these are the items I am using: -Arduino Mega 2560 -power supply A, for testing (amazon: http://www.amazon.com/KORAD-KA3005P-Programmable-Precision-Adjustable/dp/B0085QLNFM/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1401838076&sr=1-2-catcorr&keywords=korad) -power supply B, for my larger system http://www.amazon.com/Universal-Regulated-Switching-Computer-Project/dp/B00D7CWSCG/ref=sr_1_3?ie=UTF8&qid=1401838142&sr=8-3&keywords=12v+power+supply -2 TEC/peltier coolers (similar to http://www.amazon.com/YKS-TEC1-12706-Thermoelectric-Cooler-Peltier/dp/B007H2IXV2/ref=sr_1_1?ie=UTF8&qid=1401837553&sr=8-1&keywords=peltier+coolers+12+v) -1 pololu VNH3SP30 motor driver (driven by arduino PWM) http://www.pololu.com/product/705
Thanks in advance for comments/suggestions etc! :)