| 摘要 |
1,218,852. Semi-conductor devices. ENGLISH ELECTRIC CO. Ltd. 28 March, 1969 [2 April, 1968; 15 May, 1968], Nos. 15728/68 and 23116/68. Heading H1K. [Also in Division H2] A plurality of thyristors and their associated circuitry are mounted on a number of tubular cooling ducts 16 upstanding from and equidistantly spaced around an annular receptacle 11 for cooling fluid, so that the complete assembly of thyristors defines a helical path encircling all the ducts 16. In the embodiment shown the assembly is enclosed within a sealed ceramic or steel housing 14 and the cooling fluid is pumped into the receptacle 11 and up the ducts 16, which are open at the top so that the fluid passes down over the assembly into a trough within the receptacle 11 for recycling. Each thyristor has associated with it a corona shield 20, and similar shields may also be provided adjacent capacitors (5), Fig. 1 (not shown), which form part of the voltage sharing circuitry for the assembly. The gating circuits (7) are arranged so that all thyristors are gated-on simultaneously, and the circuits (7) preferably comprise bi-stable circuits each of which includes two photo-transistors irradiated by light, e.g. from a laser via mixer units 21, Fig. 2, carried by filamentary light guides 8, 9. |
