[time-nuts] High accuracy temp controller ckt

[Hal Murray]

drkirkby at kirkbymicrowave.co.uk said:
>> If you do go the TEC route, plan on a fairly big power source :).
> I'm particularly keen to avoid the requirement for high power, as I was
> thinking to make this in such a way it can be shipped and powered up all the
> time. If it could run from a few NiMH cells for 48 hours, that would give the
> option of shipping it. I don't know if that's going over the top, but it
> would be an interesting exercise. 

Shipping a TEC cooler could get interesting.  You need to get rid of the heat 
somehow.  Cooling fins on a package would be interesting.

The airlines don't like dry ice.  You could try an ice pack/gel.  If it's well 
insulated, the TEC will be off.  The heater won't take much power.  It's just 
a matter of how much insulation you need.

What's the hysteresis on a resistor?  Is it really important to ship it 
powered up?


-- 
These are my opinions.  I hate spam.