| 摘要 |
FIELD: electric engineering. ^ SUBSTANCE: switching device contains load (1), triac (2), control circuit, consisting of pulse shaper (6), electronic switch (9), threshold device (15) and time delay array (12). Load (1) is connected with triac power circuit (2), pulse shaper (6) output (7) is connected with triac control electrode (5); pulse shaper input (8) is linked with Q output of electronic switch (9); electronic switch input (11) is connected with threshold device (15) output (18) via time delay device (12). Threshold device is provided with negative voltage-sensitive input (16) and connected with triac (2) control electrode (5) by this input. Device ensures load protection from current overloading, electric motor from accidents with jamming. Analogue comparator, optical coupler or "--" transistor connected with common base against circuit may used as threshold device. ^ EFFECT: improvement of reliability, simplification, improvement of weight and dimension. ^ 3 cl, 9 dwg |
