Found in Radio Electronics from the 90s, this thermometer uses an integrated circuit that is unusual today. The sensor is a thermistor or NTC.
Suitable for battery powered microcontrolled applications this Texas Instruments circuit from its...
This amplifier with the LM1098 and LM101 by Motorola from a 1990 manual can be designed with more...
Found in a 1967 Ferranti documentation, this circuit uses a LDR from that time as a sensor....