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by JKCalhoun 45 days ago
"Temperature feedback would help if this thing has to operate for extended periods."

Rather than thermistors all over the place, perhaps an onboard program could calculate motor temperature by integrating current sent to each over time—assumed some degree of cooling (and perhaps here a single temperature sensor might measure ambient temperature of the environment… or could just assume "indoor temperature").

3 comments

I would rather just have temperature sensors over the place. More reliable.
For a toy, you might just have a simple thermal fuse.[1] ($0.78 from DigiKey, plus "tariff may apply if shipping to the United States". About $0.15 on Alibaba, if you order enough.). For a working machine for field use, you want feedback to the controller, so it can slow down or rest or something when it overheats.

[1] https://www.digikey.com/en/products/detail/cantherm/RT121/28...

Train it like Disney’s Olaf where it can adjust how it walks/stands to keep motor temperature under control.
That’s how industrial VFDs do motor overload protection, they just keep track of heat accumulation (based on current) vs dissipation (based on fan speed) and fault when a threshold is reached. Probably there’s more nuance to it, but that’s the gist of it.