Found in Popular Electronics from the 90s, this circuit can be used in tachometers. The integrated circuit is not a common component today.
This circuit was obtained from an English publication from the 70's. The circuit is still current for...
This circuit makes use of an unusual Analog Devices component today. The circuit is from a 90's...
This circuit was found in a 1974 documentation. The bipolar transistor can be the BC548 and at the...