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.
This common crystal oscillator configuration can generate signals from 1 to 20 MHz, depending on...
This burglar alarm is highly efficient, depending of course on the care with which it is...
This light relay is powered directly by the power grid by activating a 110 V relay. The LDR is of...