Electrical circuit to facilitate antenna installations - has AC bridge elements with amplified unbalance signal applied to DC bridge circuit

摘要

The electrical circuit to facilitate the manipulation of a radio antenna uses the output from a transformer (1) to feed an a.c. bridge (3) formed of resistors (13, 14, 15) one of which (4) may be set to the required value. Across diagonal of the bridge is connected an amplifier circuit (6) incorporating two transistors and a resistor (16, 17, 18). The amplified output passes to a rectifier bridge (2) through an electronic switch (7), typically a thyristor. The output of the bridge is applied to a d.c. motor, which has a relay switch and a smoothing capacitor connected in parallel.