| 摘要 |
PURPOSE:To precisely detect the decrease of gas volume due to resistance abnormality in a passage by comparing of the rotation speed detected by a speed detection circuit with the reference rotation speed previously stored, comparing a load current detected by a current detection circuit with the reference load current previously stored, and notifying abnormality. CONSTITUTION:A control circuit made to control a blower 5 is composed of a microcomputer 7, a magnetic pole position detection circuit 6 that detects the magnetic pole position of the rotor of a synchronous motor 5-1, a current control part 8 that controls the current of the synchronous motor 5-1, and a base driver 9 for transistors TR1-TR6. The microcomputer 7 receives signal 6s from the magnetic pole position detection circuit 6, and when it becomes larger than the reference minimum gas volume rotation speed as a result of performing speed operation, light up a LED to illustrate the abnormality in inlet and outlet ports. Also, previously stores the current data in the minimum reference gas volume, compares it with the 8 bit current data 11 outputs from the microcomputer 7, and lights up the LED to notify the abnormality when a load current becomes small. |
