GB571279A - Improvements relating to the activation of electrical conductors which are non-conductors when cold - Google Patents

Abstract

571,279. Heating by electric arcs. STUPAKOFF CERAMIC & MANUFACTURING CO., May 5, 1943, No. 7110. Convention date, March 19, 1942. [Classes 39 (ii) and 39 (iii)] [Also in Group XXXV] A glower formed of material which is an insulator when cold but conducting when hot, used for example as a generator of infra-red rays, as an igniter in oil burning equipment and for illuminating purposes, is heated to render it operative by means of a self-extinguishing arc between divergent electrodes. Electrodes 7, are associated with a glower 2 so that the arc when formed may climb them and become extinguished. A transformer 5 may have a winding 4 furnishing operating current and a high voltage winding 9 producing the arc; this transformer may be arranged with a magnetic shunt 11 so that the current in winding 4 may be rendered substantially constant and the winding 9 receive insufficient excitation to re-establish the arc while current is flowing in winding 4. A transformer core 30 may comprise a number of secondary windings 32 with shunts 34 so that a number of glowers 33 may operate independently under constant current. The arc gap may be directly in shunt with the glower and high frequency current may be used to produce the arc which becomes short-circuited when the glower is in operation, Fig. 4 shows a D.C. system in which an induction coil with interrupter 26 produces the arc voltage and is disconnected by a relay 22 when the glower operates. A system in which a high frequency oscillator is coupled with a supply circuit for a glower with arc electrodes in parallel is also described.