This circuit was obtained in an 80s documentation on telephony. The components used are TTL, and the power must be made with 5 V.
This configuration shows the simple way to use a varicap diode to tune an LC circuit. Capacitor C1 must be...
This circuit consists of a touch switch with optical isolation, using CMOS integrated circuits. The...
Within a range of values, this circuit converts input voltages into corresponding currents. The...