Conference reporting system with pulse modulated TDM signals - uses combiner with multichannel input section and two output sections

摘要

The multiple channel speech transmission system for reporting purposes at conferences, political meetings etc uses pulse modulation with time multiplex transmission, and light or infrared radiation. The multiple channels (M1, M2 etc) are connected to a combining stage (KZE) where the incoming needle pulses are regenerated and galvanically separated by a set of three lines with two output combiners. The input combining stage has an amplifier to increase the level of each input then a pulse shaper for regenerating the pulses, and a monostable trigger circuit. This forms a driver stage for a transistor connected by a resistance and capacitance in parallel to a light emitting diode which produces flashes, coupled to a photo diode followed by a two stage amplifier (KAE1,2) connected to a Schmitt trigger and an output driver stage.