| 摘要 |
<p>PURPOSE:To eliminate the reception unable state of a burst signal due to noise, by resetting a demodulator to its initial state when a signal which is free from phase inversion is detected. CONSTITUTION:When a normal signal burst is supplied to an input terminal 1, the biphase code has phase inversion at the converting point of each element. Therefore, the output signal of a D type FF151 is set at logic 0. Then a start- stop synchronizing means is not reset and delivers an output signal. When noise is inputted to the terminal 1, the output signal of an exclusive OR circuit 11 is set at logic 1. The output signal of the FF151 is also set at logic 1. This output signal resets latch circuits 3 and 6, a dividing circuit 8, and D type FF9, 10 and 13 respectively and is delayed by a delay circuit 152 to reset the FF151. As a result, a demodulator is reset to its initial state when the start-stop synchronizing means is started by noise and the demodulation is started.</p> |
