| 摘要 |
PURPOSE:To omit the operation required for remodeling wiring and devices other than a transformer and provide a switching function with an extremely simple construction, by providing a means for giving an alarm when detecting a stop of oil flow thereby to protect the transformer. CONSTITUTION:When a vehicle is traveling in an AC section and an oil feeding pump is operative to allow the oil to flow normally, a reed switch 1 is open, while a reed switch 2 is closed, so that the protection circuit is open as viewed from terminals (a), (b). On the other hand, when the pump suspends to shut off the oil flow, the reed switch 1 is closed, and also the reed switch 2 is closed, so that the protection circuit is closed. When the vehicle is traveling in a DC section and the transformer is inoperative and in addition the pump suspends, the reed switch 1 is closed, while the reed switch 2 is opened, so that the protection circuit is opened. Accordingly, only in the case of (B), the protection circuit is closed to give an alarm, and the abnormal operation can be discriminated from the normal operations (A), (C). It is to be noted that when the transformer is operated to allow the load current to flow, a magnetic field M is produced around conductors, i.e., a terminal 11 and an external lead 12 thereby to make it possible to close the reed switch 2 disposed in the vicinity of the conductors. |
