| 摘要 |
In a remote control signal repeater, which transmits remote control signals from a remote controller to a main device, having a bandpass filter and a level slicer, the bandpass filter is constructed of a parallel LC resonant circuit and a serial LC resonant circuit connected to each other. The resonant frequencies of the respective resonant circuits are set to the substantially same frequency. A resultant resonant characteristic having two peaks on sides of the original resonant frequency of the parallel LC resonant circuit is obtained and resonance of the serial LC resonant circuit is produced between the two peaks, thereby flattening the portion between the two peaks. The level slicer connected to the bandpass filter includes a class-C amplifier which level-slices output of the bandpass filter, a smoothing circuit which smoothes output of the class-C amplifier and a bias control circuit which variably controls the degree of class-C bias in accordance with a smoothed output of the smoothing circuit. When an undesirable continuous noise is received by a light receiving element, the class-C bias increases to cut off the received continuous noise and when a remote control signal is received, the class-C bias decreases to output the received remote control signal.
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