GB513575A - Improvements relating to resonant relays, inverters, or like electromagnetic devices - Google Patents

Abstract

513,575. Electromagnetic switches. ALLGEMEINE ELEKTRICITATS GES. Jan. 10, 1938, Nos. 778 and 779. Void. Convention dates, Jan. 9, 1937, and Feb. 5, 1937. [Class 38 (v)] In a resonant relay, inverter or like device, a permanent magnet 11 carried by a spring 7 moves over the poles 3 of the electromagnet or electromagnets 13 so that there is a very small and substantially uniform air gap between the parts 11, 3 whatever the amplitude of oscillation. In the form shown, the magnetic circuit 1, 2, 3 is energized by either A.C. or periodical D.C. passing through the coils 13. The resulting oscillation of the magnet 11 causes fixed contacts 6, adjustable by screws 8, to be engaged. Fig. 4 shows the circuit arrangements for an inverter. A source of direct current 14 energizes the coils 13 causing the contact 7 to engage a contact 6. This short-circuits the coil 13 so that the permanent magnet 11 and its spring 7 move back only to be again attracted in the manner of an ordinary interrupter. The consequent oscillation of the spring 7 between the contacts 6 causes current to flow first one way and then the other through part of the upper coil 15 of a transformer, the lower or secondary coil of which therefore supplies alternating current.