This circuit was found in a 1977 documentation. It limits the voltage from a source using zener diodes on the rectifier bridge. It is an unusual configuration today.
The figure shows how to implement an OR function with two inputs, using a relay. The relay...
The integrated circuit used in this 1987 project is not very common these days. However, if found...
Found in American documentation from the 1980s, this circuit has a diode feedback. At the exit we...