Using a pair of period A/D converters, this 3-digit circuit was found in the 1992 Radio Electronics Experimenter magazine. The sensor is a thermistor.
Of course, with a change in the cable length, the frequency can be changed as long as it is within...
This circuit is basically the same configuration as the previous one with a power stage with...
Using the ZN1034E which reaches 19 days interval, this is a simpler circuit which can be...