Apparatus for flicker protection when a servo-motor starts

摘要

An apparatus for flicker protection when a servo motor driven sewing machine starts utilizing comparators. Setting the original voltage as the reference voltage and the dropped voltage as the monitor voltage, the comparator compares the voltages and, if the difference exceeded more than the predetermined value, signals for setting the maximum electric current to the servo motor are attenuated such that the voltage drop of the electric source will be reduced.