DEVICE OF AUTOMATIC CONTROL OVER TWO-POLE LOAD IN AC CIRCUIT (VERSIONS) Russian patent published in 1997 - IPC

FIELD: automatics. SUBSTANCE: invention deals with realization of automatic devices executing periodic switching on and off with time delay of two-pole load in A.C. circuits, first of all of lighting devices in living and industrial rooms. Device has thyristor key placed in series with load and circuit of its control which includes former of time intervals on base of pulse counter and set of outer pickups of position on base of magnetically and mechanically controlled electric contacts placed in series. Load is set for specified time interval determined by word size of pulse counter. It is switched off automatically with break of any electric contact. Circuit of outer pickups is realized through high-resistance resistors which provides for electric safety of device when it is supplied from network with the use of transformer-free power supply source. EFFECT: increased electric safety of device. 2 cl, 2 dwg