Found in a radio amateur magazine of the 1980s, this circuit uses components that can still be found easily. The circuit is for NiCad batteries.
This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like...
In the figure we have the way of modulating or controlling the frequency of a relaxation...
The purpose of this circuit is to monitor the operation of an alternator in cars with a 12 V...