thermocouple probe location in side bender

[peter havriluk]

I have just finished assembling my digital controller for my heat blanket, and I would like to know how/where to locate the thermocouple probe so it can drive the digital controller to modulate the heat. My first thought is to locate the probe between the outer metal sandwich slat and the wood side being bent. This make any sense? This will create a gap between the metal slat and the wood. Dunno if that's a wise thing to do. But I am in need of information and guidance.

Thanks, folks.

[Kevin in California]

Peter i see you have the stick probe. For sure don't put it under the wood. On top of the blanket, under the slat near the waist.
If you cut the stick off, then take the two exposed wires and twist them together, you won't have the bulk and can put the end anywhere. If you can solder, put a small bead of silver/tin solder on the twist.

[peter havriluk]

The thermocouple is happy with the ends soldered together, then? Easy enough to do. I just don't know a thing about the mechanics of thermocouples.

Now to drift into over-thinking, if I'm not careful: I suspect that I ought to do whatever alterations to the probe that I want to make before I 'auto-tune' the controller. My thinking is that the heat injected into the probe alters the current flow through the thermocouple, and that's the parameter that is used to modulate the temperature. Maybe?

I also thought that maybe the thermal mass of the probe has a damping effect on temperature rate change and that joining the two wires ain't much of a mass to damp temperature swings. I could easily solder both wires to a brass strip a few inches long and emulate, sort of, the probe I just cut off the thermocouple. Does that make any sense? Even pretty it up with a bit of heat-shrink.

[Jim Ebert]

Peter, you could just get some of these and save the one you have know for controlling the temperature of your hide glue pot or something like that.
https://www.amazon.com/gp/product/B00OK ... UTF8&psc=1

[Kevin in California]

Yep Jim, I got two of those thermo's also. Peter, that is a better option probably.

[peter havriluk]

Ah, sounds good to me. Can't hurt to try.