SU951743A1 - Input telegraph device - Google Patents

Description

one

The invention relates to a communication technique and can be used in interface devices of telegraph equipment and data transmission equipment.

An input telegraph device is known that contains a positive polarity threshold element, a negative polarity threshold element, the outputs of which are connected via an amplitude selector to the input of the code conversion unit, and through an amplitude detector to another input of the amplitude selector Ci

However, the known device is characterized by an insufficiently high sensitivity and a high percentage of edge distortion of telegraph signals.

The purpose of the invention is to increase the sensitivity and reduce edge distortion.

This goal is achieved by introducing a delay element and a limiting resistance into the input telegraph device, in this case the threshold element of the positive polarity of the telegraphic signal ... and the threshold element of the negative polarity of the telegraph signal are made on transistors, the delay element consists of a transistor, two

Claims (2)

10 resistors and a capacitor, the code conversion unit is made in the form of an NAND element, while the limiting resistance is connected to the transistor base of the threshold element of the positive polarity of the telegraph signal and to the emitter of the transistor of the threshold element of the negative polarity of the telegraph signal whose collector is connected to the emitter the positive-polarity threshold element of the telegraph signal, the collector of which is connected through the first resistor 3 of the delay element to the output of the conversion unit code and through a successively connected capacitor and second resistor is connected to the base of the transistor of the delay element, the emitter of which is connected to the base of the threshold element of the negative telegraph signal, the collector of which is connected to the output of the device through the AND-NOT element of the code transistor. The phasing and emitter of the transistor of the threshold element of the positive polarity of the telegraph signal are combined. The drawing shows the electrical structure of the proposed device. The input telegraph device contains the limiting resistance 1, the threshold element of the positive polarity of the telegraph signal, made on the transistor 2, the threshold element of the negative polarity of the telegraph signal, made on the transistor 3) delay element 4, transistor 5, the first resistor 6, the second resistor 7, the capacitor 8, the code conversion block 9, the NAND element 10. The input telegraph device operates as follows. When a telegraphic parcel of positive polarity arrives, transistors 2 and 5 open, a logical zero signal is generated at the input of the NAND element 10, and a signal of the logical unit at the output of the NANDI element 10. Transistor 3 is closed. Condenser torus 8 discharged through open transistor 2. When the telegraph polarity changes, the signal from the positive to the negative transistor 2 starts to close, and the transistor 5 remains open due to the charge of the capacitor 8 by the base current through resistors 6 and 7. When the level of the negative polarity signal reaches the opening threshold transistor 3, the latter opens, and transistor 5 closes, and a logical zero signal is generated at the output of the element NE-10. In the event of a line break, transistors 2, 3, 5 turn out to be closed, and a logical zero signal is generated at the output of the NE-10 element. The proposed input telegraph device makes it possible to increase the sensitivity of the device with 3 to 4 transistors in the input circuits, since the base current of the transistors is small, due to the use of a delay element, the insertion edge distortion is reduced. Claims An input telegraph device comprising a threshold element of a positive polarity of a telegraph signal, a threshold element of a negative polarity of a telegraph signal and a code conversion unit, characterized in that, in order to increase sensitivity and reduce edge distortions, a delay element and limiting resistance are introduced. positive polarity of the telegraph signal and the threshold element of the negative polarity of the telegraph signal are made on transistors, element nt delay consists of a transistor, two resistors and a capacitor, the code conversion unit is made in the form of an NAND element, and the limiting resistance is connected to the base of the transistor of the threshold element of the positive polarity of the telegraph signal and to the emitter of the transistor of the threshold element of the negative polarity of the telegraph signal, the collector of which is connected to the emitter of the threshold element of the positive polarity of the telegraph signal, the collector of which is connected through the first resistor of the delay element to the output of the code conversion unit and through the series-connected capacitor and the second resistor is connected to the transistor base of the delay element, the emitter of which is connected to the base of the negative polarity threshold element of the telegraph signal, the collector of which is connected to the output of the device through the AND-NOT element of the code conversion unit the transistor of the delay element and the emitter of the transistor of the threshold element of the positive polarity of the telegraph signal are combined. . Sources of information taken into account during the examination 1. USSR Author's Certificate No. "03097, cl. H Qi L 11/08, 1971 (prototype) HIU txoi ri " W im I DHS e: S I I