JPS57212894A - Signal converter - Google Patents

Abstract

PURPOSE:To receive new service such as data transfer and computer even for a rotary dial type telephone set, by converting a dial signal from the rotary dial telephone set into a push button signal and transferring the push button signal from a push button dial telephone set as it is. CONSTITUTION:When a telephone set 1 is a push button dial telephone set, a push button PB signal is applied from terminals (a) and (a') and a signal converter transmits the PB signal to a transmission line via capacitors 16, 17, changeover switches 14, 15 and terminals b and b' as it is. When the telephone set 1 is a rotary dial telephone set, the dial signal applied from the terminals (a) and (a') is a DC signal. Although this signal is blocked at the capacitors 16 and 17 and not transferred to the transmission line, it is received at a dial pulse reception section 11. This reception section 11 recognizes to which figure this signal corresponds at each reception of one digit of the dial signal and applies the signal to a multi-frequency signal selecting section 10. The section 10 combines the multi-frequency signal from the PB signal generating section 13 based on the result of the said recognition to form the PB signal.