| 摘要 |
PURPOSE:To provide a combustion controlling circuit high in safety, at a low cost, and without compromising the performance of ignition and detection of a flame, by providing, between a burner and a combustion controlling circuit, higher resistors having a high breakdown strength thereby securing the insulation for preventing one from being struck by electricity. CONSTITUTION:Due to the insulation performance of a pulse transformer 7 and the resistors 9, 21, the burner 1 and a commercial alternative current power source 1 are separated enough in view point of the prevention of one from being struck by electricity, and therefore if an electrode 8 becomes in touch with the burner 1, there is no such a risk. At the other positions of the resistor 21, the discharge current for the ignition becomes little so as to lower the ignition performance. On the other hand the auto-transformer 20 is inexpensive. Thus the combustion controlling circuit having the same performance as the prior art in view point of the ignition, the detection of a flame and the safety can be provided at a low cost. |
