| 摘要 |
PROBLEM TO BE SOLVED: To provide an overload detecting device for an induction motor at a low cost, which has simple constitution and high reliability. SOLUTION: An induction motor 10 in which fluctuation of a driving current is small with respect to the number of revolution, and a driving circuit 22 for driving the induction motor 10 are installed. A voltage detecting means 24 for detecting a voltage between both terminals of a phase leading capacitor C of the induction motor 10 or a winding voltage L1 is installed. A judging means like a photocoupler 30 is installed and judges the overloaded induction motor 10 when the output of the voltage detecting means 24 becomes lower than or equal to a prescribed value. |
