Dead Peltiers act that way!
@jremington
I did not know that breadboard had limitations in current. I have absolutely not respected that since my peltier is connected to it. Thank you for the information, I will connect that an other way. (Deconnect the mosfet - which is IRLZ44N- from the breadboard and use male female thread rather than male male).
I will to the draw up and send it, you re right I am not being detailed enough, sorry.
Thank you for the idea of a quick test, I am going to try that and will keep you update.
@Paul_KD7HB
I m afraid you may be right. I will follow the instructions of @jremington to check on the "life" of my peltier device and we ll see.
Thanks both of you for your quick answers !
J
1 Like
These two tests can also give the same results for a BAD MOSFET.
It would be better to make the tests with a 10 ohm resistor in place of the TEC and set the power supply to 5V
Connect like this, very simple:
So the peltier was, indeed, dead. I have not had the chance to try the system yet (I will have "re"-access to the power source in 1 week), but i look forward to trying both of my circuits (1st with mosfet and 2nd with the relay) and will keep you posted.
During this time, i will build a circuit with a 10kOhm (or a 10Ohm i have not decided yet) NTC thermistor to measure the temperature of a peltier in order to draw some beautiful graphs^^ and (mostly) use it instead of the thermocouple K which is a bit too wide to get under the heatsink properly. I don't wanna change the subject of this topic so as to this new little mission i won't ask questions, but so you know how this is going.
Thanks a lot everybody, have a great day !
That usually happens when one applies full power without a heat sink on the hot side of the element.
For typical Peltier elements (e.g those used in consumer grade coolers), if the temperature anywhere in the element exceeds about 80 degrees C, it will be destroyed.
Check the data sheet for absolute maximum ratings.
I honestly doubt that. Not what you are saying of course, but why my peltier did die. I have made a lot of mistakes but one thing sure, I did put a big heatsink on the hot side 
and before I began the "regulation" project, peltier was working great with this heatsink.
I explained why Peltier elements usually die. You are certainly welcome to entertain alternative theories about what happened in your case.
By the way, did you apply a thin layer of thermal transfer paste between the Peltier and the heat sink, and use some sort of compression to ensure efficient heat transfer?
2 Likes
When working with MOSFETs you reference (where you generally place the black meter lead) the source, not the drain. Looking at the data sheets you see parameters such as Vgs (Voltage Gate Source) This will be positive to Turn on a N-Channel and Negative to turn on a P-Channel MOSFET.
When your Arduino output is high the Drain should measure about zero. When the Arduino output is low the Drain should measure 12V. If it does this it is working properly. If you are not sure about your load you can also parallel a resistor with it.
Also put in parallel a 560R and a LED, so you cab SEE some sort of average power being supplied to the Peltier unit.
Tom.... 
Hi everyone,
It works !
I just wanted to thank you all for your help and piece of advice, especially @jremington and @gilshultz.
Wish you the best !
Great job! Thanks for letting us know, It makes me feel good that I actually helped somebody solve a problem. I know @jremington feels the same way. I am looking forward to your next project, have fun and enjoy Arduino!
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.