| 摘要 |
PURPOSE:To simplify a compressor by detecting the presence or absence of an abnormal vibration phenomenon by a regenerative current to eliminate the necessity of confirming the resonance point by a test. CONSTITUTION:When an abnormal vibration occurred in certain frequency and voltage ranges occurs, a regenerative current flows to a shunt resistor 4, and a voltage is generated across the resistor. When the regenerative current becomes the prescribed value or higher so that a photocoupler 14 becomes ON, an interrupt signal is input to a microcomputer 5 through a buffer 15. The microcomputer 5 alters to an interrupt flow by the input of an interrupt signal. As a result, a command for generating waveform slightly varied in a voltage or a frequency by V or F is output to a rectifying and smoothing circuit 7 and an inverter 3. Thus, a motor 2 slightly displaces from a resonance point to suppress the abnormal vibration. |
