| 摘要 |
PROBLEM TO BE SOLVED: To prevent the indoor environment from degrading by preventing the operation of the compressor in an air-conditioner from being stopped due to increase of the load. SOLUTION: A DC voltage is switched through a transistor module 3 and applied to a motor 4 for driving a compressor and a transistor in the transistor module 3 is driven according to the value of a preset V/F pattern. In this regard, a phototransistor in a photocoupler circuit 6 is turned on/off depending on the current flowing through a shunt resistor R1. When the phototransistor is turned on, output voltage from an integration circuit 7 drops and when the phototransistor is turned off, output voltage from the integration circuit 7 increases. Output voltage from the integration circuit 7 is fed to the A/D conversion port of a microcomputer 10 and detected (input current to the transistor module 3 is detected). Furthermore, a decision is made whether the detected output voltage comes within any one of a plurality of preset zones and the value of a current V/F pattern is corrected or operation of the compressor is stopped. |
