Overcurrent detecting device for a DC motor

Abstract

An overcurrent-detecting device for a DC motor includes a converter for changing a current signal to a voltage signal in a motor; an integrator for comparing an input signal from the convertor with a first reference voltage, and for integrating an excessive value of the reference voltage; and a detector for comparing an input signal from the integrator with a second reference voltage, sensing an overcurrent when the input signal is smaller than the second reference voltage, and outputting a resultant signal. In detecting an overcurrent of the DC motor, the device integrates a higher voltage than a reference voltage, and then detects an overcurrent when the DC motor is constrained. This overcurrent-detecting device, therefore, can be exactly operated by a small-capacity capacitor without incorrect operation with respect to noise and abrupt overload, while not permitting forced operation in the initial operation, and also can be operated quickly in response to an actual mechanical constraint having a reasonable overcurrent.

Dependencies are inferred from the claim text.