Unlatchable four polarisation mode triac - has approximately equal gate currents in all four modes

摘要

The triac, which can be unlatched by a suitable pulse to the gate electrode in any of its four polarisation operating modes, has a sensitivity which is approximately equal in each mode. The physical structure is approximately the same as that of orthodox triacs, except that there is no overlap between the outermost 'N' doped layers of the triac (N1,-N3). An intrusion (10) is formed at the innermost end of the lower layer (N2) penetrating through the intermediate 'P' and into the centre 'N' type layer (N2). Gate currents required to effect unlatching for the four modes are approximately, 11,11,17, and 17mA.