This circuit is from an American documentation from the 90s. The transistors are of power and must be equipped with good heat sinks as well as the integrated voltage regulator.
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...