| 摘要 |
PURPOSE:To supply a power supply only as required by detecting the reception state at the time of start of reception while the power supply to a down- converter is stopped and then supplying power to the down-converter whenever it is necessary. CONSTITUTION:A control circuit 8 discriminates whether or not a main power switch is closed and when an affirmative result is obtained, the supply of power to a down-converter 4 is controlled to be stopped and satellite broadcast channels are selected sequentially from the 1st channel till the 15-th channel and the reception level is sequentially detected. Then the control circuit 8 discriminates whether or not the broadcast can be received by any channel and when the result indicates a negative answer, it is discriminated that an exclusive antenna for satellite broadcast reception is connected. Then after supply of power to the down-converter 4 is started, the satellite broadcast channels are selected sequentially again from the 1st channel till the 15-th channel to detect the reception level and when the broadcast is received by any channel, the power supply to the down-converter 4 is intermitted. |
