| 摘要 |
PURPOSE:To transmit plural kinds or plural digits of PB signals in a voice guide to a service device surely by using a circuit detecting a signal level of various signals and a detection circuit of the PB signals so as to compare the outputs of these circuits by a comparator circuit. CONSTITUTION:When a voice guide signal shown in figure (a) and PB signals shown in figure (b) exist, a signal level detection circuit 6 generates a detection signal if the synthesized signal of both the signals exceeds a prescribed level shown in figure (c). On the other hand, a PB signal detection circuit 5 detects the presence of the PB signal and plural detection outputs as shown in figure (e) is generated depending on the change in the amplitude of the superimposed voice guide signal. Thus, the comparator circuit 7 is used and after the PB detection signal is generated, until the level reaches a prescribed a prescribed value or below, a comparison output is generated as shown in figure (f) so as to eliminate inconvenience of plural number of times of generation of the PB detection signal due to voice. |
