| 摘要 |
PURPOSE:To obtain the DC voltage for operation of a remote control receiving circuit and the like without reducing the S/N of signal system by a method wherein a switching device is connected in series with the input coil of a power source transistor and besides, the input coil of another transformer is connected in parallel. CONSTITUTION:When a relay RY is in a non-driven state and a contact point S1 is in OFF position, the output voltage of a rectification circuit 2 is supplied to an oscillation circuit 3 through the input coil of a transistor T3. The oscillation circuit 3 performs a self-oscillation. An output voltage is obtained at a rectification circuit 9 by the current running on the input coil of the transformer T3, this voltage is supplied to the remote control circuit 8, and a receiver is placed in a standy state. When the relay RY is driven by a remote control signal and an ON position is given to the contact point S1, an exciting current runs to the input coil N1 of the transformer T1 by the oscillation circuit 3, and a voltage is supplied to load RL through a rectification and smoothing circuit 5 from the output coil N2 of the transformer T1, thereby allowing the control circuit 6 to stabilize the output voltage. |
