Can I drive Peltier Cooler Modules Using Linear Regulators

[Arsh ahmad]

Hello,
I want to design a controller for the Peltier module that needs about 6 Amps at 12 volts, But I also want to change its temperature when I want to. One possible solution I can think of is  Design a Regulator which I can power with a 6A supply of 12 volts and then I can adjust the output voltage of the Linear Regulator in this way I can control the power through the TEC.

I want to know if it will work or if I need another method.

Thank you

[james_s]

Sure it will work, but it's not going to be very efficient. I think a better way is to use PWM, depending on the thermal time constant of your setup the frequency could be quite low. An off the shelf PID controller would probably work.

[Arsh ahmad]

High Voltage TEC controllers are not available so I need a method to drive them for now I need an Open Loop Control. I need to know how to control TEC current or Voltage through PWM since it will require an efficient filter.

[Wolfram]

Direct PWM is not ideal for Peltier elements, as losses are proportional to the RMS current while heat transfer is proportional to average current. A PWM waveform has an unfavorable ratio of average to RMS current (1/sqrt(2) = 0.71 for 50 % duty cycle), reducing the system efficiency. As mentioned, a linear regulator will have significant losses as well. A switching regulator would be my chosen approach, for example a buck converter if the supply voltage is higher than the required maximum voltage of the Peltier element.

[Wallace Gasiewicz]

Is exact temp control necessary? Or can an old fashioned on/off switch work?
If it is an incubator for laboratory purposes the temp range is more exact than if it is just to keep your bananas cool.
A bang-bang circuit that turns on the cooling module at its most efficient voltage might be helpful and less wasteful of power especially if the power is a battery.

[Siwastaja]

You totally can, efficiency is crap, but it's crap anyway with Peltiers. If you manage to successfully cool the Peltier itself, which is not trivial at all, then you no doubt manage to cool the linear regulator which can work with high temperature difference to the atmosphere, unlike the Peltier.

With PWM, you risk physically damaging the Peltier. Plus efficiency is crap at <100% duty. Approximately equally crap to the linear regulator solution.

Best option is adjustable DC/DC converter.