JPS56155662A - Operation of electrostatic dust collector - Google Patents

Abstract

PURPOSE: To drive an electrostatic dust collector constantly with a proper power factor, by detecting a phase shift between an inputted electric power source voltage and a main circuit current or its basic component, generating a voltage signal corresponding to the phase shift, and automatically controlling the capacity of a phase- advancing capacitor in accordance with the level of the voltage signal.

CONSTITUTION: An inputted electric power source voltage V₁ charged onto an input terminal is phase-controlled with a thyristor control part 2. The phase-controlled voltage is charged to a high voltage transducer 4 through a current limiting reactor which limits a spark current and a load short circuit current and which improves the wave-form of a voltage to be charged to a dust collector 5. By the high voltage transducer 4, the phase-controlled voltage is increased and changed to a direct current and then charged to the collector 5. On the other hand, a voltage detector 7 detects the inputted electric power source voltage V₁, and a current detector 8 detects an intermittent main circuit AC I₁. The detected signals are inputted to a phase shift detector 9. The phase shift detector 9 changes the phase shift based on the two detected signal to a corresponding voltage signal, and feeds the voltage signal to a change-over circuit 10, to control the capacity of a phase-advancing capacitor by switches S₁WS_n.

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