Designing an analog circuit can be a frustrating experience, as noted by Nick Cornford in his Design Idea (DI), “DIY RTD for a DMM.” With a fortnight’s struggle, I completed the design of 4 mA to 20mA ...

The MOSFET in Figure 1 is used as both a heater and a temperature sensor in a thermostatic circuit. Figure 1 Circuit diagram for using a MOSFET as a thermostatic heater. The circuit can be used as a ...