FREEZER CONTROLLER AUTOMATICALLY CONTROLLING FREEZER ON OPTIMUM COOLING AND DEFROSTING CONDITIONS

摘要

PURPOSE: A freezer controller is provided to automatically control a freezer on optimum cooling and defrosting conditions, and prevent overload of a compressor. CONSTITUTION: A key input unit(21) has a plurality of keys for user input. A temperature sensor(11) senses a freezing temperature. A current sensor(12) detects a current value of a compressor for obtaining a voltage signal. A thermocouple for defrosting detects frosting and defrosting states of an evaporator. A first microcomputer(U4) preliminarily stores program data necessary for operating a freezer, and executes control commands for the compressor, the evaporator, and an evaporator fan. A flash memory(U3) backs up the data stored on the first microcomputer in real time for storing programmed data in case of an electricity failure and restoring the data to the first microcomputer when the electricity failure is restored. A relay driving unit(41) drives each relay(LY1,LY2,LY3) supplying driving power to the compressor, the evaporator fan, and a defrosting heater. A display unit(51) displays characters, a current temperature, and adjusting figures. A second microcomputer(U5) monitors the relay driving unit for generating a reset signal to the first microcomputer.