I would just like to know if the following is ever possible with the Arduino before I start diving into this.
The part which I have not seen on the WWW is the setpoint temperature and automatically adjusting PWM Duty cycle.
QuoteThe part which I have not seen on the WWW is the setpoint temperature and automatically adjusting PWM Duty cycle.There are two ways of doing this. The first is the easy banging, turn on if it is too hot, turn off if it is to cold.The second is to use the same principals of servo control where the closer you are to where you want to be the slower you go. This can involve a lot of maths. Try looking up servo control loops.
This is exactly what I am looking for. The first option is to inefficient + in a Computer the On/Off part can make the 12V line in the PSU fluctuate.
QuoteThis is exactly what I am looking for. The first option is to inefficient + in a Computer the On/Off part can make the 12V line in the PSU fluctuate.I think inefficient is the wrong word, it is actually very effecent but is subject to overshoot and undershoot. However using PWM is not going to do anything about the PSU fluctuations, that is a problem with the PSU not being able to supply enough current. It will be worse with PWM because of the constant rapid switching.
Although my electronic knowledge is low. I do think that when I run the PWM a 2+kHz(recommended for Peltiers) the PSU won't be affected by the fluctuations. my is idea to have fairly slow changes in PWM duty cycle
because of this the PSU needs to be able to withstand the 20A that is being drawn by the TEC 50% of the time even though that switching frequency in the TEC is over 2000 times a second?
Say that the TEC I am going to use draws 20A at 12V.If I run a 50% duty cycle on the PWM then the the TEC will be as if it is working at 6V 10A.
will this method require cooling of the FET I might use
"N-channel MOSFET 96A 100V TO220 IRFB4410"
Quote"N-channel MOSFET 96A 100V TO220 IRFB4410"This is not a logic level FET and so can't be driven directly from the arduino. You either need a logic level FET or you need to boost the arduino's 5V output signal to at least 10V with a transistor or another FET.