| 摘要 |
PURPOSE:To enable the ringing of a telephone bell initially to a sound and sound volume having a subscriber's choice by counting a calling signal, thereby modifying the calling sound. CONSTITUTION:When the calling signal is received, a calling signal detecting circuit 6 detects the calling signal, connecting a changeover witch 1 to an S2 side, counting the calling signal on the calling signal counting circuit 7. Thus, until the count value of the counter circuit 7 attains the prescribed value, the sound feeder 2 sends out the sound and the sound volume having the subscriber's choice via the speaker 3. When the counter circuit 7 reaches the prescribed value, reset pulses are sent out to a detector 6 to connect the switch 1 with S1 side, to ring the bell 4 as usual.
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