Figure 1 Feedback from the soldering iron's PTC temperature sensor controls the on-time vs the off-time of M2 to regulate the iron's temperature to the selected value. Most parts are not critical. A ...

I’ve been using Pt100 temperature probes a lot lately. Low end ones are not expensive and some are good up to 500 degrees C. It’s basically a PTC thermistor with better linearity in the ...