This circuit was found in a 1966 General Electric documentation. It makes use of direct contact water sensors and therefore requires an isolation or low voltage relay drive transformer.
We found this circuit in a Hands-On Electronics from the 90s. The circuit must be connected to an...
Found in old documentation, this circuit applies to almost any common operational amplifier or...
This circuit can be used to power loads up to 5 A and the transistors must be mounted on large...