THREE-PHASE SWITCH CONTROL DEVICE BUILT AROUND TRIACS Russian patent published in 2002 - IPC

FIELD: electrical engineering; phase-failure protection of three-phase loads. SUBSTANCE: device has triacs connected to supply mains phases; first group of three diodes interconnected through anodes and connected through their cathodes to respective phases of supply mains; second group of two diodes and thyristor connected through anodes to output terminals of switch and interconnected through cathodes, gate electrode of thyristor being connected to control unit. Control unit of device is distinguished by absence of heat loss with switch turned off, twice as low voltage applied to control button with device turned off, and practically no voltage across button in ON- and OFF-state of device. EFFECT: provision for protecting load against phase failure with open circuit in triacs. 1 dwg