SU1184100A2 - Output loading device for cable video line - Google Patents

Abstract

1. OUTPUT DEVICE FOR LOADING THE CABLE VIDEO LINE by auth. No. 1109919, characterized in that, in order to increase the length of the line, a winding is inserted into the choke of the disagreement corrective two-pole network, connected between the cable and video line outputs. 2. The output device according to claim 1, characterized in that a capacitor and / or circuits are connected in parallel with the choke and the boost winding and / or the matching two-terminal circuit, each of which consists of a series-connected resistor and capacitor. eo j;

Description

The invention relates to wired lines used primarily in television for transmitting signals over large-length connecting cables, and is an improvement in the mainstream model, No. 1109919. The purpose of the H3pfrete is to increase the extension of the video line. ; In the drawing of a representative circuit, the electrical circuit of the proposed device is in principle. The device contains a matching two-terminal 1, a cable 2, a two-terminal 3 disagreeing corrections, a choke 4, a capacitor 5, resistors 6, capacitors 7, a boost winding 8, a capacitor 9, resistors 10 and capacitors 11. The device works as follows. At low frequencies, while the inductive resistance of the drossel 4 is much less than the wave resistance of cable 2 and the matching two-terminal network equal to its resistance 1, the output of cable 2 is matched. From the matched cable 2 output, the signal through the input winding winding enters the high-resistance cable video line output. The signal is transmitted without distortion and loss, since the output of the cable video line is a high-resistance one — a lot more than the inductive resistance introduced by. EXISTING Winding 8. At these frequencies on choke 4, the signal is negligible and after transformation remains negligible on the boost winding 8. Thus, at all of the indicated low frequencies at the output of the cable video line, the signal is the same as at the matched output cable 2. From By increasing the frequency, the resistance of the drops 4 increases and the output of the cable 2 is unloaded. Simultaneously, the signal voltage decreases at matching two-port 1 and increases at choke 4. When the resistance of throttle 4 becomes much greater than the characteristic impedance of cable l 2 and the matching two-pole cable 2 output goes to idle mode, the signal at the cable output is twice as large as when matching the cable at these frequencies, almost all of 02 is released at throttle 4. The injected front winding 8 transforms the voltage from drossel 4 to the output of the video cable and increases it by a factor of t ansformatsii (2-7) formed by them avtotransformatoraS Since the signal cable with the video line is supplied to the high-impedance circuit when transformed signal is not changed. As a result of the mismatch between the output of cable 2 and transformation, the signal at high frequencies increases at the output of the cable video line by 4-14 times, i.e. by 12-23 dB. The shunting of the throttles 4 and the over-winding 8 by the capacitor 5 gives a resonant and even higher rise of high frequencies, contributing to better correction of the attenuation of the cable at the upper limit of the transmitted frequency band. Resistors 6 and capacitors 7 allow you to select the flatness of the input high frequency sweep and input it from lower frequencies. Shunting of a matching two-terminal 1 by a capacitor 9 and by chains of resistors 10 and capacitor 11 increases the high-frequency signal at choke 4 and through the secondary winding 8 even more so at the output of the cable video line. In addition, they allow input of a boost from lower frequencies. On the symmetrical cable video line, the discrepant correction two-terminal 3 is turned on symmetrically (for example, divided in half and each half included in its own wire). The high frequency boost introduced reduces the non-uniformity of cable attenuation 2. Since cable 2 and the output circuits in question are minimal-phase, the corresponding part of the non-uniformity of the group time of cable 2 is simultaneously corrected. The necessary suppression of reflected signals is provided by introducing a correction only at high frequencies, in which the attenuation of cable 2 exceeds 12-17 dB when the input of cable 2 video line is matched or exceeds 125-35 dB when it is mismatched. Than

3 11841UO4

the greater the attenuation of the cable is 2, the less is the output of the cable video line with

lower frequencies are introduced to the core-6 dB of the basic invention to

rektsi - raising high frequencies and 12-23 dB, ie by 6-17, dB, that the signal at the output of the ka-air will be magnified to further increase the length

easy video line. 5 cable of adjustable video line

The input winding 8 and maintain the signal level.

increases the signal level of the video output.

Claims (2)

1. OUTPUT DEVICE FOR LOAD OF CABLE VIDEO LINE by ed. No. 1109919, characterized in that, in order to increase the length of the line, a boost winding is inserted between the cable and video line outputs into the choke of the mismatching correcting two-terminal network. 2. The output device according to π. 1, characterized in that a capacitor and / or circuit are included in parallel with the inductor and the boost winding and / or the matching two-terminal, each of which consists of a resistor and a capacitor connected in series. Q $ SU .., 1184100