Found in an Electronic Design and 1970s, this circuit uses transistors of the time. The transistors can be replaced with equivalents and the relay is 12 V depending on the power supply.
The circuit is from the 1990 Motorola Linear Databook. The circuit can be implemented with other...
Found in Texas Instruments documentation from the 1980s, this circuit applies to digital signal...
This circuit was found in a 1980s US publication. There may be some difficulty in obtaining the...