METHOD OF MEASURING ROTATIONAL FREQUENCY OF FAN USED FOR GAS BOILER

摘要

PURPOSE: A method is provided to minimize an error occurring due to an assembling tolerance and noises of a fan motor in the measurement of the rotational frequency of a fan. CONSTITUTION: A pipeline water supply valve(35) for supplementing water in the shortage of water in a water tank(20) is installed between a heating water circulation pipe(2[) and a direct water inlet pipe(34). A bypass pipe(38) is provided to circulate water by forming an internal closed circuit of a gas boiler(1) when a heating distributor or a heating distribution pipe is clogged. A low temperature sensing thermistor(TH3) is installed in a casing(2) of the gas boiler. The rotational frequency of a fan is calculated by renewing and averaging a current pulse(N) and specific prior pulses(N-1,N-2,N-3,...).