PURPOSE: To stop the operation of a compressor when refrigerant in a circulating circuit has become short by a method wherein a refrigerant shortage detecting sensor, detecting the gas and liquid mixing condition of refrigerant and outputting an electric signal for opening a power supply circuit for driving a compressor, is provided in a refrigerant conducting pipe at the high-pressure side in the refrigerant circulating circuit of a cooling device.
CONSTITUTION: One terminal of a refrigerant shortage sensor 9 is connected to a power supply while the other terminal of the same is grounded through an amplifier 11 and the solenoid coil 12 of an electromagnetic opening and closing switch 10. An optical sensor is employed in a refrigerant shortage sensor 9 which detects the mixing ratio of gas and liquid of the refrigerant based on the amount of permeation of light. When the refrigerant becomes short, the ratio of mixing of gas to liquid is increased whereby the refrigerant shortage sensor 9 detects it and outputs an electric signal amplified by an amplifier 11. According to the conduction of the electric current, the solenoid coil 12 is excited and an automatic opening and closing switch 10 is put OFF. Accordingly, the driving power supply circuit of a compressor 2 is opened and the operation of the compressor 2 is stopped. For your reference, a self heat generating type thermistor can be used instead of the optical sensor.
KURIHARA SUSUMU
KOBAYASHI KAZUMITSU
JAPAN ELECTRONIC CONTROL SYST
| JP2116660B | ||||
| JPS6310366A | 1988-01-16 |