TIMER OF REFRIGERATORS DEFROSTING Russian patent published in 2009 - IPC H01H43/10 F25D21/08 

FIELD: mechanics.

SUBSTANCE: invention refers to automatics. The device includes power supply, timer, heater, defrosting finish sensor, compressor, voltage suppressor, first and second rectifiers, first and second extinguishing elements, three-pin electromagnetic relay movable contact of which is connected to power supply second pole. Timer inverting input is connected with power supply first pole through heater and with second fixed relay contact through defrosting finish sensor. Timer common leg is connected with power supply second pole. Timer output is connected with second fixed relay contact through two series-connected circuits. The first circuit is formed by relay winding and threshold element. The second circuit is formed by first rectifier and first extinguishing element. Common point of the first and the second circuits is connected with timer common leg through voltage suppressor and with first fixed relay contact through circuit of series-connected second rectifier and second extinguishing element (the third circuit). The first fixed relay contact is connected with power supply first pole through compressor. According to the second version the device includes power supply, timer, heater, defrosting finish sensor, compressor, voltage suppressor, first and second rectifiers, first and second extinguishing elements, three-pin electromagnetic relay movable contact of which is connected to power supply second pole. Timer common leg is connected with power supply second pole. Timer inverting input is connected with power supply first pole through heater and with second fixed relay contact through defrosting finish sensor. Timer output is connected with relay winding first output, the second output of which is connected with the second fixed relay contact through series-connected first rectifier and first extinguishing element. Common point of relay winding second output and circuit formed by series-connected first rectifier and first extinguishing element is connected with timer common leg through voltage suppressor and with fixed first relay contact through circuit of series-connected second rectifier and second extinguishing element. The first fixed relay contact is connected with power supply first pole through compressor. Timer is performed with additional control input connected with voltage suppressor. Additional control input provides the possibility for timer to receive a signal about power in the circuit after emergency shutdown.

EFFECT: structure simplification, increase of operation safety at the expense of decreasing the requirements for timer elements permissible work voltage, decrease of discrete elements quantity, facilitation of optimal version choice for certain conditions of use.

3 cl, 3 dwg