Found in Radio Electronics from the 90s, this thermometer uses an integrated circuit that is unusual today. The sensor is a thermistor or NTC.
This simple circuit is powered by the logic circuit itself. Components are still common, although...
This circuit was found in Radio Electronics from July 1990. The circuit produces the sound of the...
This circuit was found in a 90s EDN. In it we have the use of LEDs and diodes to stabilize the supply...