Patent ID: 6171063
Filing Date: 2001-01-09
Classification: H02M

Abstract:
A control circuit for vibrating compressors for converting d-c voltage into ac voltage to supply a-c voltage to a vibrating compressor comprisinga MOS-FET transistor for driving said vibrating compressor,a timer IC for generating pulses to switch said MOS-FET transistor,a timer forced-operation circuit for forcibly reversing the output of said timer IC at a timing at which a counter-electromotive voltage generated by said vibrating compressor during the OFF period of said MOS-FET transistor is restored in the vicinity of 0 volts,a driver for driving said MOS-FET transistor based on the output, of said timer IC, said driver including a capacitor for cutting d-c components in a gate of said MOSFET transistor so that said MOS-FET transistor is protected from damage due to malfunction of said control circuit, anda pulse width changing circuit for detecting an input voltage input into said vibrating compressor and lowering said input voltage to said vibrating compressor by changing the pulse width of output pulses of said timer IC when said input voltage is higher than a predetermined voltage which would cause damage to a valve of the vibrating compresor due to an overrun of a piston of the vibrating compressor.