AVR-Chat

>
>
> Seems like you could put a resistor next to the crystal and a thermistor
> and just hold a temperature (use a power transistor and PWM to vary the
> heat from the resistor).


They make xtal ovens like this, but the power consumption is a problem in
many applications.  In my repeater application, the oven would be about
200mA with the rest of the repeater drawing 30mA  Makes a BIG difference if
you're solar powering, and none at all if you can plug into the wall.
Battery backup time is affected, but for us if there's something going on
that knocks out the power, then the system will likely be busy, and the
transmitters draw WAY more power (100W and 80W) than the ovens.

Just depends on the application.

Digital watches normally use a precision heater, and far larger than you'd
think.


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