this is my first post in the community and I’m a big fan of Arduino:)
I’m generally confident in programming and moderate confident in electronic but I’m stuck right now and I’m looking for advice.
For a project I have to: drive one (several if it works) Peltier (TEC) element. Running the same face hot or cold, according to user selection. Also with the ability to set the desired temperature (hot or cold).
Therefore my objective is: to drive a TEC element, maintaining the ability to inverse the polarity. Using cost-effective components because it’s a really low budget project.
Components: for a technical reason, I need to use this very small peltier. Rated 0.8v 3.2A.
Looking for a cost-effective solution for driving a TEC with Arduino, I found several posts here and on google, suggesting a motor h-bridge.
The problem is that usually the motor drivers are rated for higher VmotorIn voltage, >3 volts.
The only viable and cost-effective solution I found is this small driver from pololu.
I built the circuit, and it actually worked. (diagram attached)
But there are several problems:
- I have to turn up the voltage from 0.8v to 1.4v at the driver V motor In. Otherwise, I have no response from the TEC at all.
- Nonetheless, I have a significant voltage drop on the TEC. I supply to the driver 1.4v but I measure 0.4v on the TEC terminals.
The TEC works, it reaches the temperature, I can switch the polarity and so on.
But I do not understand the voltage drop, and the driver runs very hot.
I would also like to find a different solution because right now I’m driving the TEC only a 1.7A (driver internal limit)
While I could safely push up to 75% of the power (let’s say 2.5A).
So my question are:
- how can I drive a TEC element rated at 0.8v?
- How can I improve my circuit with low-cost components?
- Can I use PID and PWM with this TEC/circuit? In other h-bridge solution, I found PID and PWM a 200khz is usually implemented.
Thank you all very much,