FIELD: generation of different types of tone signals for users of public telephone system. SUBSTANCE: address signals generated by means of first counter are applied to large number of tone tables for successively feeding tone signal corresponding to each address signal to respective buffer. Then first counter generates signals for selecting tone signal (except address signals in tone tables) in such a way that it is possible to successively output respective tone signals out off tables. Simultaneously first counter sends signals for selecting tone signal to circuit for selecting clock pulse data supplied to it from clock pulse table and for outputting them. In the result clock pulse data from output of clock pulse selection circuit interrupt tone signals successively received from tone tables. Then signals are fed to respective buffer for outputting them to PCM-channel. Apparatus provides sending of necessary tone signal with use of simple counter without high-cost microprocessor. EFFECT: reduced cost of making apparatus. 2 cl, 4 dwg
Authors
Dates
2001-10-10—Published
1997-10-09—Filed