This circuit was found in documentation from the 90s. The operational amplifier admits an equivalent. The circuit has frequency ranges up to 5kHz determined by R1.
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...