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.
This circuit for photography uses was found in the Electronics Experimenter Handbook Special...
It is like to the previous circuit with a lock that keeps the LED on at the end of the timer. The...
This circuit, with two operationals, was obtained from an old American publication. Operational...