| 摘要 |
PURPOSE:To enable reduction of cost and the size of a control box, by a method wherein control of combustion and setting of temperature are executed through the knob of the same moving contact piece. CONSTITUTION:When a knob 11a is moved to the high temperature side, the potential of a turn-over input terminal 32 is increased to a value higher than a reference voltage, the output potential of a comparator 31 is inverted and decreased to an L, a PNP type transistor 41 is turned ON to energize a combustion control circuit 60, and combustion is rendered controllable. When a feed hot water temperature is increased after a burner 3 is brought in a combustion state, the resistance value of a thermistor TH 25 is decreased, and the potential of an input terminal 52 is decreased to a value lower than that of an input terminal 53. By means of an output signal from a temperature regulating circuit 50, the opening of a solenoid valve 2 is reduced through the combustion control circuit 60. When heating capacity of the burner 3 is reduced and the temperature of feed hot water is decreased to a value lower than a set temperature, according to a temperature difference therebetween, the opening of the solenoid valve 2 increased and regulated, and is controlled so that it is coincident with the set temperature of the knob 11a. |
