Transient characteristics of thermoelectric coolers

Electromechanical Fans, Thermal Management
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1

Hello there,

I am a researcher at the University of Tübingen and I need to update the hardware of an in-house developed chilled-mirror hygrometer (CMH). For that I need a microTEC with fast response (it needs to reach steady-state within 0,1 seconds) and I could not find any information regarding the transient characteristics of the microTECs sold by DigiKeys…

My operating conditions are:
T_cold: between -5 and 20 °C
Max temperature difference: dT_max = 10 °C
Time to reach steady-state: 0,1 seconds
Max dimensions: width = 5mm, length = 5mm, height = 5mm

Would you have any thermoelectric cooler that satisfies my projects? Or info about the transient response of microTECs sold by DigiKey?

3

Hello nclibardi,

That is a difficult application.

Considerations:

  1. The thermal mass of your associated components must be considered. This includes both the hot and cold sinks.

2) The delta for your 100 ms step change was not specified. Time is proportional to the step difference. This thermal system response is similar to the first order charge and discharge of a capacitor.

  1. For long TEC life, it is better to apply power slowly - linear as opposed to on - off. This will prevent thermal shock resulting in longer life.

  2. A Proportional Integral Derivative or similar control system will be required to achieve reasonable stability. On / Off control is likely to have significant overshoot and oscillation.

DigiKey does sell several TEC in this size range. Recommend contacting the individual manufactures to determine the dynamic characteristic of the devices. They may have ideas for achieving faster response time while staying within the physical and electrical limits of the device.

Best Wishes,

APDahlen

P.S. Recommend you purchase a few small devices and conduct experiments to determine the suitability for your application.

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