| 摘要 |
PROBLEM TO BE SOLVED: To set the operating frequency of a switching amplifier so as not to disturb reception of a tuner in a broadcast wave reception system that amplifies a sound signal from the tuner with the switching amplifier. SOLUTION: A control part 4 controls a carrier frequency received by the tuner 2 and the operating frequency of a switching operation in the amplifier 3. A table showing a relation between each clock frequency and a carrier frequency to be reception disturbance is stored as a clock frequency of a reference clock of the amplifier 3 in a ROM 42 of the control part 4, wherein two clock frequencies that satisfy a condition of reception disturbance to a portion of many carrier frequencies included in an AM broadcast wave band are set beforehand such that the both clock frequencies do not satisfy the condition of reception disturbance over the same carrier frequency. When the control part 4 sets a reception frequency in the tuner 2, the control part 4 determines a clock frequency not to be reception disturbance with reference to the table of the ROM 42, and sets the clock frequency in the switching amplifier 3. COPYRIGHT: (C)2011,JPO&INPIT
|
