CONTROL SYSTEM FOR CONSTANT CURRENT

摘要

PURPOSE: A constant current control device is provided to reduce costs regarding the replacement of a facility by operating a constant current control device without using an additional power supply part. CONSTITUTION: A power supply part(20) forms a constant voltage circuit by charging a voltage applied to both ends of a switching device(10). The switching device controls the average of an output current. An error amplifier(40) transmits a control value to the switching device by comparing the signal of a current limit value with a real current value which is fed back from a filter part. The filter part(30) converts a voltage into an analog RMS voltage by integrating a pulse square wave voltage from a shunt(50). The filter part is composed of a differential operation amplifier which applies the feedback signal to the error amplifier.