POWER CONTROLLER OF ELECTRIC CLEANER

摘要

PURPOSE:To enable to switch the constant air flow control to 2 stages or more by providing a wind pressure sensor and a converter of a level set. CONSTITUTION:The output of an air flow sensor 7 is amplified by an amplifier 27, and connected through a changeover switch 30 to the non-inverting terminal of a comparator 24. The switch 30 switches between the case of inputting to the output from the amplifier 27 and the case of directly shortcircuiting. The output F of the comparator 24 compares a triangular wave D with the output E of the amplifier 27. This signal F is differentiated by a differentiator which is formed of a capacitor 32 and a resistor 33, applied to the base of a transistor 34, and the collector of the transistor 34 is connected to the gate terminal of a bidirectional thyristor 8 through a current limiting resistor 37.