| 摘要 |
PURPOSE:To perform automatic correction with high reliability, by making accurate the discrimination of time signal, through the production of time correction signal after a given time elapsed from the leading time of normal time signal received with the time signal discrimination circuit. CONSTITUTION:The correct time signal received is inputted to the Schmitt circuit 12 via BPF10 of the time signal discrimination circuit, and the circuit 12 produces the rectangular wave signal having the width from the leading of the correct time signal to the disappearance of the correct time signal, FF13 is set and the AND gate 14 is closed. Thus, clock is fed to the one minute timer 15 via the gate 14 and the time correction signal is fed to the counter circuit after one minute when the leading time of the received correct time signal to perform automatic time correction. On the other hand, the clock via the AND gate 16 opened with the pulse 2 from the circuit 12 is counted at the counter 17 and no time correction is made if the gate 16 is opened via the circuit 12 in response to noise with the reset of timer and FF13 before the duration period of correct time signal. Thus, the time signal can accurately be discriminated and automatic time correction with high reliability can be made. |
