Using a capacitor as a sensor, this circuit was found in the 1989 Radio Electronics Experimenter magazine. The circuit must be assembled in a shielded box.
We found this circuit in the 1974 Ferranti transistor manual. Transistors are from the time, being...
This temperature sensor circuit was found in an old American documentation. The components used...
This separator filter is from an old publication. The capacitor can have 10 to 47 uF of the...