Two-way pump for gas boiler, control circuit thereof, and control method thereof

摘要

A two-way pump control circuit capable of reducing impact noise generated by a two-way pump while changing a mode of a gas boiler is provided. In the circuit, first and second switches switch an alternating current power which is selectively applied to a two-way pump motor as a two-way pump driving voltage according to an operation state of the gas boiler. A driver for selectively drives the first and second switches according to the operation state of the gas boiler. A zero crossing signal generator detects a zero point from the alternating current power during a constant cycle to generate predetermined width of pulse signal. A controller generates first and second control signals to control the first and second switches according to the operation state of the gas boiler in response to the pulse signal from the zero crossing signal generator, respectively, and controls a duty cycle of the first and second control signals during a mode change of the gas boiler in order to control a phase of the two-way pump driving voltage.