| 摘要 |
PROBLEM TO BE SOLVED: To surely reduce power consumption during an off state and during a timer operation by providing an oscillation stopping means temporarily stopping oscillation of a non-insulated lowering pressure type switching power source circuit during the off state or during the timer operation. SOLUTION: An output port Pϕof a microcomputer 41 leading to an oscillation circuit 26 is connected with an oscillation stopping means 56 temporarily stopping the oscillation circuit 26 during an off state or during a timer operation. When a (t) second counter of the microcomputer 41 passes prescribed (t) seconds in a lower power consumption mode, voltage of the output port Pϕis reversed (an H level). This reverse is continued for (t) seconds and subsequently becomes an L level till (t) seconds elapses. Namely, the output port Pϕof the microcomputer 41 is reversed for every (t) second. Therefore, the oscillation circuit 26 is temporarily stopped while the output port Pϕis in the H level and a driving signal to a transistor 25 is not outputted. Therefore, the period of the driving signal outputted from the oscillation circuit 26 becomes larger than that at the time of a normal mode and power consumption of the oscillation circuit 26 is reduced. |
