GB525133A - Improvements in circuit arrangements for operating electric discharge devices - Google Patents

Abstract

525,133. Supply for electric discharge devices. GENERAL ELECTRIC CO., Ltd., HARRIS, N. L., and KIRKNESS, R. H. Feb. 14, 1939, No. 4855, [Class 38 (iv)] [Also in Group XL] In the supply circuit arrangements for electric discharge devices having a pair of thermionic electrodes 2, Fig. 3, adapted to be heated independently of the discharge at least during the starting period by current passing through the usual control choke 3 and through a switch 5 short-circuiting the discharge path until the discharge is initiated, the short-circuit connecton includes a coil 7 wound reversely upon the choke so that at starting the impedance of the choke is reduced. In a form in which the choke carries secondary windings supplying the thermionic electrodes, the short-circuiting connection includes a reversely wound coil on the core in opposition to the main winding. The switch 5 may be operated to the open position by a heating element which is traversed both by the current through the switch and by the discharge current. In abnormal cases, where the current through the electrodes is (with the switch closed) inconveniently large the winding 7 is wound to assist the winding 3.