Abstract: A circuit for driving a relay having at least two contacts and an excitation coil. An AC power source is connected to the contacts of the relay for applying a voltage of a prescribed frequency to these contacts. A detector section compares a pulse current, induced in phase with the AC current supplied from the AC power source, with a reference value, thereby producing a detection signal. In accordance with this detection signal, the positive and negative phases of a signal having a cycle longer than, and being asychronous with, said AC current, are delayed alternately or at random, thereby generating a timing control signal. This timing control signal closes and opens said relay at random timings, thereby protecting the relay from contact welding.

Abstract: An electric refrigerator is disclosed which includes first and second coolers independently disposed in a freezer and a refrigeration chamber, respectively, a compressor for delivering a refrigerant therefrom, an electromagnetic valve for switching a refrigerant channel including the first and second coolers between a first referigerant flow path for supplying the refrigerant to only the first cooler and a second refrigerant flow path for supplying the refrigerant to both the first and second coolers, and a control circuit for causing the electromagnetic valve to form the first refrigerant flow path for a predetermined time interval and for causing the electromagnetic valve to form the second refrigerant flow path by preventing interruption of the compressor when the predetermined time interval has elapsed and an air temperature in the refrigeration chamber is higehr than a predetermined temperature.

Abstract: A high speed freezing apparatus in use for a refrigerator. In the freezing apparatus, evaporators for the cold and freezing chambers are coupled in a series relation with respect to a compressor. An electromagnetic valve is provided in parallel with the evaporator for the cold chamber. When a high speed freezing start signal is produced from an operating section mounted on a front panel of a door for the freezing chamber, a timer circuit provided in a control section is operated. An operating condition of the compressor is detected by a detecting transformer and a given signal is produced from a start-failure preventing circuit. The start signal is transferred through a gate circuit to a relay portion only during the time that the given signal is transmitted to a gate circuit. Through the relay portion, the compressor and the electromagnetic valve are driven, so that the refrigerant is supplied to only the evaporator for the freezing chamber to start the high speed freezing operation.