| 摘要 |
An oil burner unit comprises an oil pump and a fan which are both driven by the same motor. The pump (3) is of the kind which begins to operate only above a predetermined critical speed. When starting the unit, the motor is first energised by a first current supply circuit having an impedence (6) and thus operated at a reduced number of revolutions at which the pump (3) is out of operation but the fan (2) is working to ventilate the combustion chamber. After the lapse of a predetermined period of time the number of revolutions is increased to cause the pump to operate, whereby the combustion can begin. The changeover is achieved by means of a time delay device which closes a second circuit to increase the motor speed and thereby cause the pump to deliver oil. |
