| 摘要 |
PURPOSE: A safety device of a gas valve is provided to improve the confidence and the safety of a gas heater by controlling the switch of a switching transistor for deciding to open or close after comparing and detecting an output signal of a firing transformer, flame detection signal, and overcrowding sensing signal of a micom. CONSTITUTION: A safety device of a gas valve comprises : a flame detection part(24) to compare an output signal of a firing transformer, flame detection signal, and overcrowding sensing signal of a micom with the standard signal and to output several comparing signals ; a micom(22) to supply various kinds of controlling signal to the around devices and to control the system on the whole ; a driving part(21) to open and close a gas valve by driving several relays(RY2)(RY3) as several comparing signals of a flame detector(24) and a controlling signal of a micom(22). And a flame detection part(24) consists of the first comparing part(25) comparing an output signal of a firing transformer and flame detection signal with the standard signal and outputting the first comparing signal, a transistor for the first signal reversal(26), a transistor for the second signal reversal(27) reversing an overcrowding detecting signal of a micom(22), and the second comparing part(28) comparing a reversal signal of a transistor(27) with the inner standard signal and outputting the second comparing signal. And a driving part consist of a buffer(23) amplifying a controlling signal of a micom(22), a switching transistor(Q2) supplying the driving power source(12V) to several relays(RY2)(RY3), and a gas valve opened and closed as driving of relays(RY2)(RY3).
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