Having figured out the dual-thermistor circuit, I made a small mold from cut-up credit card-ish things, laid down a layer of JB Weld epoxy, and positioned the thermistor assembly just above it:

A generous dollop of epoxy filled in the rest of the mold and it cured overnight:

Extract the final result, file off the rough edges, and then epoxy it to the thermal block:

And then it’s all good!
The thermal resistance from aluminum-to-thermistor seems to be no big deal compared with the thermal inertia of the block and Peltier module.
Comments
2 responses to “Peltier PWM Temperature Control: Thermistor Brick”
Nice soldering on the MOSFET Ed, the deserve to be sleeved or some heat shrink tubing!
Ah, but remember what’s going on here: apart from this first poor crash-test dummy, those MOSFETs will be soldered to the wires, screwed to the block, tested, and then returned to the heap: 15 minutes, tops!