Device coupling transmitter to transmission line - includes transformer secondary whose impedance is reduced from high to low value by short circuiting primary when transmitter is active

Abstract

Abstract An information transmission line has a number of transmitters and receivers connected for transmitting and receiving coded information along the line at frequencies between several hundred Hertz and several MHz. Each transmitter applies pulse code signals through two lines (D,D) to respective AND gates which are opened by a control signal on a control line (23) to apply the code signals through V-MOS transistors and a pulse transformer (17) to the transmission line. The connection of the pulse transformer to the line includes a control transformer secondary (18) above primary can be short circuited by two transistors (27,28) controlled by the control signal. When the transmitter is active the control transformer primary is short circuited to present negligible impedence,while when the transmitter is inactive the primary is open circuited to present a high impedence to the line and present the transmitter connection affecting the line.

Inventors

• 👤 Andre Martin

Bibliographic Details