This circuit was obtained from Motorola documentation from 1969. The setting applies to other operating systems, including lower supply voltages. The zener determines the output signal.
This unit is intended to power 2 AA or AAA battery powered applications from the car battery,...
We found this circuit in the 1974 Ferranti transistor manual. Transistors are from the time, being...
This ingenious circuit was found in a 1990s Popular Electronics. The oscillator is a 555 and the...