This circuit was obtained in an 80s documentation on telephony. The components used are TTL, and the power must be made with 5 V.
Found in Electronics Today International in the 90s, this circuit turns an operational on and off...
At dusk this circuit triggers a relay switching lamps. The circuit can be powered from 6 to 12 V...
This second-order low-pass Salen-Key filter was obtained from an American 1980s documentation. Formulas...