GB1176079A - Improvements in or relating to Electronic Switching Arrangements. - Google Patents

Abstract

1,176,079. Converting, ASSOCIATED ELECTRICAL INDUSTRIES Ltd. 5 Aug., 1968 [4 Sept., 1967], No. 40255/67. Heading H2F. [Also in Division H3] In a switching arrangement controlling several electronic switching devices in a group, separate firing pulses for at least two electronic switching devices 4 of a sub group are derived through two auxiliary transformers 5, the primary winding of these auxiliary transformers are energized from the secondary toroidal winding 3 of a common main transformer 2 and annular magnetic cores of at least two main transformers surround a conductor 1 which is coupled by the cores to induce the secondary windings of the main transformers. As shown a number of main transformers 2 controls via auxiliary transformers 5 series or parallel connected thyristors 4, transistors, thyratrons or thermionic valves. The primary windings of the auxiliary transformers 5 may be connected as shown in series, or in series parallel or in parallel (Fig. 3, not shown). The transformers can be protected against excessive voltage due to open circuit conditions of one or more of the electronic devices 4 by connecting resistors in shunt with the secondary winding of the resin transformer, or in shunt with one of the windings of each auxiliary transformer.