In the figure we have the configuration of series regulator protector suggested by Motorola in 1968 documentation. The transistors are of the time, being able to be used modern equivalents.
The sensor for this circuit, found in a 1992 publication, is a phototransistor. The power is...
This circuit can generate signals of frequencies up to 1 or 2 MHz, tuned in the capacitor. The...
Suggested by Philips documentation from 1968, this circuit uses components from the era that can...