This circuit uses two relays that switch when the voltage exceeds the value given by zener D2. The circuit is from a Radio Electronics magazine from April 1975.
This circuit causes the relay to be energized when the input voltage exceeds the voltage value of...
The circuit we present is suggested by Linear Technologies (www.linear.com) and makes use of an...
Found in American documentation from the 90s, this circuit can be used as a shield with the...