TRANSMISSION AND RECEPTION CIRCUIT FOR DATA TRANSMISSION

摘要

PURPOSE:To obtain an inexpensive transmission/reception circuit which performs transmission of data through a short-distance transmission line at a low speed, by using just several units of transistors with no compensation needed for waveform distortions. CONSTITUTION:Transistors TrQ1 and Q2 constitute a double power supply SEPP (Single Ended Push-Pull) type transmission circuit. The codes of + or - levels are transmitted from terminals T3 and T4 of a pulse transformer PT when the TrQ1 or Q2 is turned on by a transmission signal sent from a logical circuit CC for control of transmission. Thus the transmission is possible for a double-current binary code. Then the transmission of a ternary code is also possible by turning off both TrQ1 and Q2. When a terminal T2 has a higher potential than a V0 terminal after reception of the transmitted code, a TrQ3 is turned on and the variation of the collector potential of the TrQ3 is fetched by the circuit CC. While a TrQ4 is turned on when the terminal T2 has a lower potential than the V0 terminal. Then the variation of the collector potential of the TrQ4 is fetched by the circuit CC after receiving a level shift through a TrQ5. In a reception mode of the ternary code, the TrQ3 or Q4 is turned on after reception of + or - levels and then turned off with ''0''.