A properly-tuned PID system does not cycle! Dana
On Mon, Dec 21, 2020 at 6:49 PM Bob kb8tq <[email protected]> wrote: > Hi > > Finding a data sheet on a TEC that goes past *very* basic stuff is > essentially > impossible. The bottom line is that the people who make them very much > want to sell them to you. Finding information in those data sheets that > suggest > problems … not so much. > > The problem is (mainly) physical. The expansion / contraction of the > device is > a big deal. KHz level PWM is (likely) not a problem. Aggressive cycling > from > something like a PID is indeed an issue. > > Bob > > > On Dec 21, 2020, at 6:43 PM, Hal Murray <[email protected]> wrote: > > > > [Old mail, context is TECs] > > > > [email protected] said: > >> If the drive current ripple is too high fatigue failure from cyclic > >> thermomechanical stress can be significant. > > > > Do good data sheets say anything about that? > > > > Is there a frequency term in there? Can I use PWM, which is as much > ripple as > > you can get, as long as the frequency is high enough? If yes, ballpark > of how > > high? > > > > Physically, where is the heat/cold generated? Is it mostly at the > junction? > > > > -- > > These are my opinions. I hate spam. > > > > > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
