DEFROSTING TIMER Russian patent published in 2005 - IPC

FIELD: automation; periodic turn-on of actuating mechanisms of ac automatic-control devices.

SUBSTANCE: proposed defrosting timer has power supply, time counter, heater, end-of-defrosting sensor, compressor, first rectifier, first and second dropping components, and three-contact relay; movable contact of the latter is connected to second pole of power supply; count input of time counter is connected through heater to second fixed contact of relay and through end-of-defrosting sensor, to first pole of power supply. Common lead of time counter is connected to first fixed contact of relay and through compressor, to first pole of power supply. Inputs of first rectifier are inserted between fixed change-over contacts of three-contact relay through first dropping component; output of first rectifier is connected to that of time counter through series-connected threshold element and relay coil. Newly introduced in timer is second rectifier one of whose inputs is connected through second dropping component to second pole of power supply, and its other input is connected to first fixed contact of relay; second rectifier output is connected to time counter output also through series-connected threshold element and relay coil.

EFFECT: reduced power requirement due to lower operational loss and enlarged functional capabilities of timer.

1 cl, 1 dwg