| 摘要 |
PURPOSE:To make it possible to continue cooking even in case of the tentative flow of overcurrent by detecting continuously the number of slow revolutions of a motor for a certain time or by operating an overcurrent circuit breaker when the number of slow revolutions is detected again a certain time after detecting the number of slow revolutions. CONSTITUTION:A speed detection section 4A inputs a detection signal of the number of revolutions of a motor 1A in a control circuit 3A. When the motor 1A is in a state overloading or locking, the number of slow revolutions is detected in the control circuit 3A. When the number of slow revolutions is detected again after passing a certain time or when the number of slow revolutions is detected continuously for a certain time, the breaking operation is performed by a by-pass circuit being branched from bb point by flowing the current capable of operating to an overcurrent circuit breaker 2A immediately from aa point. And, at this time, a certain time is longer than the time required for one time detection. In a locking state of motor, an optional time is set by confirming the time before the motor 1A becomes abnormal to the motor of each cooking machine.
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