FIELD: electrical engineering.
SUBSTANCE: proposed apparatus that incorporates provision for warning about any fault in three-phase supply mains under control by means of warning lights and for protecting load connected thereto, such as three-phase motor, against operation under phase-failure conditions has light-emitting diode matrix, current-limiting components, three-phase mains under control, half-wave rectifier, audible warning device, trimmer resistor, voltage regulator diode, three-phase optoelectronic relay for controlling three-phase motor, thyristor optocoupler, power supply, limiting resistor, and switching component.
EFFECT: enlarged functional capabilities.
1 cl, 1 dwg
