| 摘要 |
<p>1,193,096. Semi-conductor devices. ALLMANNA SVENSKA ELEKTRISKA A.B. 24 Oct., 1967, [25 Oct., 1966] No. 48278/67. Heading H1K. A thyristor is provided with an auxiliary contact P electrically connected to the ignition current contact S1. Contact P is connected to a point on a metal layer 12 on the periphery of base layer 2 which is separated by a circular groove 10 from the remainder of the body of the device, at which separated periphery the breakdown voltage is lower than the breakdown voltage elsewhere and thus where ignition will first take place. Main contacts K 0 and A are provided on the cathode 1 and anode 6 respectively. An auxiliary cathode K 1 is electrically connected to the control device S 0 of the main thyristor. The connections between the contacts P and S 1 , and K 1 and S 0 , may be resistive or reactive impedance elements, and may take the form of metal layers on the surface of the body. In place of a completely circular groove, there may be a groove (19), Fig. 7 (not shown), of limited length corresponding to a recessed area outside which is a ridge (20) to which the auxiliary contact is connected. A metal layer (22) in contact with the ridge reaches almost to cathode K 1 and has a current concentrating lip (24) projecting towards the auxiliary cathode K 1 . There may be several auxiliary cathodes connected in cascade.</p> |
