The circuit given below was found in the National Semiconductor Linear Applications Handbook. The base is an operational transconductance amplifier.
This low power audio amplifier was found at 1992s Popular Electronics. Transistors are general...
This circuit was found in a 1990 documentation. It uses very common transistors still today and...
This Schmitt optical trigger with LDR was found in old documentation. The relay must be sensitive, or an...