CN2901748Y - Anti-intercept broadcast device for satellite TV broadcast - Google Patents
Anti-intercept broadcast device for satellite TV broadcast Download PDFInfo
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- CN2901748Y CN2901748Y CN 200520131841 CN200520131841U CN2901748Y CN 2901748 Y CN2901748 Y CN 2901748Y CN 200520131841 CN200520131841 CN 200520131841 CN 200520131841 U CN200520131841 U CN 200520131841U CN 2901748 Y CN2901748 Y CN 2901748Y
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Abstract
A signal-interception-proof system for satellite television broadcasting belongs to the field of the signal monitoring and controlling devices for satellite television broadcasting system. The high input impedance differential amplifier of the signal-interception-proof system is connected with the first display driver and a comparison circuit, and a voltage reference source and a satellite receiver are connected with the high input impedance differential amplifier while another voltage reference source is connected with the second display driver and the comparison circuit, wherein the comparison circuit is connected with the alarming circuit and the video audio switching circuit which is connected with the satellite receiver. When the satellite television broadcasting signals are under attack, the input level for the satellite receiver will rise as well as the AGC level of the satellite receiver, so that once the difference value between the level of the illegal signal and that of the normal signals exceeds the threshold level of the receiver, and the ACG signal level exceeds the voltage reference, the video audio switching circuit will be driven to cut off the signals or switch into the spare video audio signal output, at the same time, the alarming circuit is driven to generate warning sound.
Description
Technical field
The utility model relates to a kind of satellite television broadcasting anti-intercept broadcast device, and it belongs to signal monitoring and control appliance in a kind of satellite television broadcasting receiving system.
Background technology
Satellite television broadcasting is the main path of present stage central and provincial TV station propagation TV signal.The Falun Gong practitioner is to the attack method of satellite television broadcasting signal, be to adopt and by the identical parameter of signal to attack, utilize high-power transmitter to the satellites transmits illegal signals, at receiving terminal when the difference of illegal signals level and normal signal level surpasses receiver threshold, normal signal is taken as background noise and blocks broadcast, and illegal signal then is received and broadcasts.In order to resist the attack of Falun Gong to satellite television broadcasting, the method that adopts mainly contains three kinds at present.The one, the transmitting power of raising normal signal overrides illegal signals when under attack.The shortcoming of this method is that transmitting power can not infinitely increase, and too high transmitting power might be damaged satellite repeater.The 2nd, close satellite repeater when under attack, the shortcoming of this method is to close transponder can make signal interruption all on this transponder.The 3rd, turn-off receiver power supply at Headend with manual method when under attack, the shortcoming of this method is a poor in timeliness, uncertain factor is many.
Summary of the invention
It is a kind of when the satellite television broadcasting signal is under attack that the purpose of this utility model is to provide, and can cut off the video and audio signal of satellite receiver immediately automatically, thus the equipment that stops illegal TV signal in cable television network, to be broadcasted.
The purpose of this practical property is achieved in that a kind of satellite television broadcasting anti-intercept broadcast device, and it is made up of cabinet, power supply and circuit;
Circuit comprises high input impedance differential amplifier circuit, comparator circuit, two groups of display driver circuits, warning circuit and AV switcher circuit, and two groups of display driver circuits have first display driver and second display driver to constitute; The high input impedance differential amplifier circuit is connected with first display driver with comparator circuit simultaneously, there is reference voltage to be connected with the high input impedance differential amplifier circuit with satellite receiver, there is reference voltage to be connected with second display driver with comparator circuit simultaneously, comparator circuit is connected with the AV switcher circuit with warning circuit simultaneously, and the AV switcher circuit also is connected with satellite receiver.
The high input impedance differential amplifier circuit includes differential amplifier (U1A), (U1B), (U1C) and resistance, 4 pin of differential amplifier (U1A) connect positive source, 4 pin are connected with 3 pin by resistance (R9) simultaneously, 3 pin are by potentiometer (R10) ground connection, 11 pin ground connection, 2 pin while and resistance (R1), (R2) connect, the other end of resistance (R2) is connected with resistance (R5) with 1 pin simultaneously, resistance (R5) is with being connected with 9 pin of differential amplifier (U1C), between 9 pin of differential amplifier and 8 pin, be connected with resistance (R7), 8 pin are output, 10 pin while and resistance (R6), (R8) connect, and by resistance (R8) ground connection; The other end of resistance (R6) is connected with 7 pin of differential amplifier (U1B), and cross-over connection has resistance (R3) between 6 pin of differential amplifier (U1B) and 7 pin, and 5 pin are the input of AGC, and 6 pin are connected with 2 pin of differential amplifier (U1A) by resistance (R1).
Comparator circuit comprises comparison amplifier (U4) and triode (Q1), 1 pin of comparison amplifier (U4) is connected back ground connection with 4 pin, 8 pin connect positive source and are connected with the collector electrode of triode (Q1), 7 pin are connected with the base stage of triode (Q1) by resistance (R17), also be connected simultaneously with the AV switcher circuit, 2 pin are connected with 8 pin of differential amplifier (U1C), and 3 pin are connected with second display driver.
Two groups of display driver circuits divide first display driver and second display driver, wherein first display driver comprises that first driving amplifier (U2) and first shows diode row, 2 pin of first driving amplifier (U2) are connected back ground connection with 4 pin, 3 pin, 9 pin and connect positive source after 6 pin are connected, 5 pin are connected with 8 pin of differential amplifier (U1C), and 1 pin, 18 pin, 17 pin, 16 pin, 15 pin, 14 pin, 13 pin, 12 pin, 11 pin, 10 pin show the corresponding connection of diode row with first respectively; Second driver comprises that second display driver (U3) and second shows diode row, 2 pin of second driving amplifier (U3) are connected back ground connection with 4 pin, 3 pin, 9 pin and connect positive source after 6 pin are connected, 5 pin are connected with 38 pin of comparison amplifier (U4), also be connected with (R12) simultaneously with resistance (R11), resistance (R11) and (R12) be connected across between 3 pin and 4 pin, 1 pin, 18 pin, 17 pin, 16 pin, 15 pin, 14 pin, 13 pin, 12 pin, 11 pin, 10 pin show the corresponding connection of diode row with first respectively.
Warning circuit comprises warning amplifier (U6) and loudspeaker, cross-over connection resistance (R18) between 1 pin of warning amplifier (6) and 2 pin, and 3 pin ground connection are connected with loudspeaker between 5 pin and 6 pin, and 6 pin are connected with the emitter of the triode (Q1) of comparison circuit.
The AV switcher circuit includes integrated circuit (U5), resistance and electric capacity, 7 pin ground connection of integrated circuit (U5), 2 pin connect positive source, cross-over connection has electric capacity (C9) between positive supply and ground, (C10), 5 pin are connected with input (V2) by electric capacity (C1), 14 pin are connected with input (A2L) by electric capacity (C2), 16 pin are connected with input (A1L) by electric capacity (C3), 3 pin are connected with input (V1) by electric capacity (C4), 10 pin are connected with input (A2R) by electric capacity (C5), 9 pin are connected with input (A1R) by electric capacity (C6), 4 pin are connected the back and are connected with 7 pin of comparison amplifier (U4) with 13 pin, 8 pin are connected with output (AR) by electric capacity (C7), 1 pin is connected with output (AL) by electric capacity (C8), 12 pin are connected with output (V) with electric capacity (C11) by resistance (R15), between resistance (R15) and electric capacity (C11), be connected with resistance (R16), and by resistance (R16) ground connection, by resistance (R14) ground connection, pass through resistance (R13) ground connection between input (V1) and the electric capacity (C4) between input (V2) and the electric capacity (C1).
Owing to adopted such scheme, satellite receiver automatic gain control level as measurement parameter, being input to high impedance differential amplifier circuit and reference voltage subtracts each other, difference is delivered to first display driver and comparator after amplifying, reference voltage is adjustable, make the automatic gain control level be presented at the precalculated position of diode strip display, differential amplifier circuit has high input impedance, and is very little to the influence of satellite receiver; Comparator circuit compares difference amplifying signal and reference voltage, reference voltage is adjustable, reference voltage is than the high 1.5V of difference amplifying signal under the normal condition, strip second shows that diode parallelism strip second shows many three led lightings of diode row, when the satellite receiver incoming level increases 3dB, difference amplifying signal voltage surpasses reference voltage, comparator output becomes high level by low level, the driving warning circuit is reported to the police, and drives the standby video/audio signal of being outputted to of AV switcher circuit simultaneously; First display driver drives first shows that diode row shows the satellite receiver incoming level in real time, and second display driver drives second shows that diode row shows anti-intercept broadcast device action thresholding.
When the satellite television broadcasting signal was under attack, the satellite receiver incoming level improved rapidly, and the AGC level increases in the receiver.According to the relation between receiver incoming level and the AGC level, a reference level is set, when the difference of illegal signals level and normal signal level surpasses receiver threshold-signal level, the AGC signal level surpasses this reference level, look the output of audio switch circuitry cuts video/audio signal or switch to standby video/audio signal output thereby drive, drive warning circuit simultaneously and send chimes of doom.Native system is simple and reliable, and response is fast, and cost is low.
Description of drawings
Fig. 1 is a satellite television broadcasting anti-intercept broadcast device system block diagram.
Fig. 2 is a satellite television broadcasting anti-intercept broadcast device electrical schematic diagram.
Embodiment
As shown in Figure 1, satellite television broadcasting anti-intercept broadcast device circuit comprises:
Differential amplifier circuit.The automatic gain signal (AGC) and the reference voltage of satellite receiver are subtracted each other, and difference is delivered to display driver 1 and comparator after amplifying.Reference voltage is adjustable, is presented at the precalculated position of diode strip display to guarantee signal.Differential amplifier circuit and display driver circuit combine, and make the variation of the corresponding satellite receiver incoming level of each diode 1dB.Differential amplifier circuit has high input impedance, and is very little to the influence of satellite receiver.
Comparison circuit.Difference amplifying signal and reference voltage are compared, and reference voltage is adjustable.Reference voltage is than the high 1.5V of difference amplifying signal under the normal condition, strip second shows that diode parallelism strip first shows many three led lightings of diode row, when expression increases 3dB when the satellite receiver incoming level, difference amplifying signal voltage surpasses reference voltage, and comparator output becomes high level by low level.
Display driver circuit.Be divided into first display driver and second display driver.The first display driver drives strip first shows that diode row shows the satellite receiver incoming level in real time.The second display driver drives strip second shows that diode row shows anti-intercept broadcast device action thresholding.
The AV switcher circuit.Under the normal condition, the comparator output low level, the video/audio signal that satellite receiver is come is by looking frequency switch circuit output.When occurring intercutting, comparator output high level, standby video/audio signal is by looking frequency switch circuit output.If there is not standby video/audio signal, then look not output of frequency switch circuit.
Warning circuit.When occurring intercutting, warning circuit is by loud speaker output alarm sound.
The model of various elements is seen accompanying drawing 2 (satellite television broadcasting anti-intercept broadcast device electrical schematic diagram).
Claims (1)
1, a kind of satellite television broadcasting anti-intercept broadcast device, it is characterized in that: it is made up of cabinet, power supply and circuit;
Circuit comprises high input impedance differential amplifier circuit, comparator circuit, two groups of display driver circuits, warning circuit and AV switcher circuit, and two groups of display driver circuits have first display driver and second display driver to constitute; The high input impedance differential amplifier circuit is connected with first display driver with comparator circuit simultaneously, there is reference voltage to be connected with the high input impedance differential amplifier circuit with satellite receiver, there is reference voltage to be connected with second display driver with comparator circuit simultaneously, comparator circuit is connected with the AV switcher circuit with warning circuit simultaneously, and the AV switcher circuit also is connected with satellite receiver;
The high input impedance differential amplifier circuit includes differential amplifier (U1A), (U1B), (U1C) and resistance, 4 pin of differential amplifier (U1A) connect positive source, 4 pin are connected with 3 pin by resistance (R9) simultaneously, 3 pin are by potentiometer (R10) ground connection, 11 pin ground connection, 2 pin while and resistance (R1), (R2) connect, the other end of resistance (R2) is connected with resistance (R5) with 1 pin simultaneously, resistance (R5) is with being connected with 9 pin of differential amplifier (U1C), between 9 pin of differential amplifier and 8 pin, be connected with resistance (R7), 8 pin are output, 10 pin while and resistance (R6), (R8) connect, and by resistance (R8) ground connection; The other end of resistance (R6) is connected with 7 pin of differential amplifier (U1B), and cross-over connection has resistance (R3) between 6 pin of differential amplifier (U1B) and 7 pin, and 5 pin are the input of AGC, and 6 pin are connected with 2 pin of differential amplifier (U1A) by resistance (R1);
Comparator circuit comprises comparison amplifier (U4) and triode (Q1), 1 pin of comparison amplifier (U4) is connected back ground connection with 4 pin, 8 pin connect positive source and are connected with the collector electrode of triode (Q1), 7 pin are connected with the base stage of triode (Q1) by resistance (R17), also be connected simultaneously with the AV switcher circuit, 2 pin are connected with 8 pin of differential amplifier (U1C), and 3 pin are connected with second display driver;
Two groups of display driver circuits divide first display driver and second display driver, wherein first display driver comprises that first driving amplifier (U2) and first shows diode row, 2 pin of first driving amplifier (U2) are connected back ground connection with 4 pin, 3 pin, 9 pin and connect positive source after 6 pin are connected, 5 pin are connected with 8 pin of differential amplifier (U1C), and 1 pin, 18 pin, 17 pin, 16 pin, 15 pin, 14 pin, 13 pin, 12 pin, 11 pin, 10 pin show the corresponding connection of diode row with first respectively; Second driver comprises that second display driver (U3) and second shows diode row, 2 pin of second driving amplifier (U3) are connected back ground connection with 4 pin, 3 pin, 9 pin and connect positive source after 6 pin are connected, 5 pin are connected with 38 pin of comparison amplifier (U4), also be connected with (R12) simultaneously with resistance (R11), resistance (R11) and (R12) be connected across between 3 pin and 4 pin, 1 pin, 18 pin, 17 pin, 16 pin, 15 pin, 14 pin, 13 pin, 12 pin, 11 pin, 10 pin show the corresponding connection of diode row with first respectively;
Warning circuit comprises warning amplifier (U6) and loudspeaker, cross-over connection resistance (R18) between 1 pin of warning amplifier (6) and 2 pin, and 3 pin ground connection are connected with loudspeaker between 5 pin and 6 pin, and 6 pin are connected with the emitter of the triode (Q1) of comparison circuit;
The AV switcher circuit includes integrated circuit (U5), resistance and electric capacity, 7 pin ground connection of integrated circuit (U5), 2 pin connect positive source, cross-over connection has electric capacity (C9) between positive supply and ground, (C10), 5 pin are connected with input (V2) by electric capacity (C1), 14 pin are connected with input (A2L) by electric capacity (C2), 16 pin are connected with input (A1L) by electric capacity (C3), 3 pin are connected with input (V1) by electric capacity (C4), 10 pin are connected with input (A2R) by electric capacity (C5), 9 pin are connected with input (A1R) by electric capacity (C6), 4 pin are connected the back and are connected with 7 pin of comparison amplifier (U4) with 13 pin, 8 pin are connected with output (AR) by electric capacity (C7), 1 pin is connected with output (AL) by electric capacity (C8), 12 pin are connected with output (V) with electric capacity (C11) by resistance (R15), between resistance (R15) and electric capacity (C11), be connected with resistance (R16), and by resistance (R16) ground connection, by resistance (R14) ground connection, pass through resistance (R13) ground connection between input (V1) and the electric capacity (C4) between input (V2) and the electric capacity (C1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520131841 CN2901748Y (en) | 2005-10-24 | 2005-10-24 | Anti-intercept broadcast device for satellite TV broadcast |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520131841 CN2901748Y (en) | 2005-10-24 | 2005-10-24 | Anti-intercept broadcast device for satellite TV broadcast |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2901748Y true CN2901748Y (en) | 2007-05-16 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520131841 Expired - Fee Related CN2901748Y (en) | 2005-10-24 | 2005-10-24 | Anti-intercept broadcast device for satellite TV broadcast |
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| Country | Link |
|---|---|
| CN (1) | CN2901748Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103219978A (en) * | 2012-01-21 | 2013-07-24 | 广芯电子技术(上海)有限公司 | Audio frequency switching device |
-
2005
- 2005-10-24 CN CN 200520131841 patent/CN2901748Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103219978A (en) * | 2012-01-21 | 2013-07-24 | 广芯电子技术(上海)有限公司 | Audio frequency switching device |
| CN103219978B (en) * | 2012-01-21 | 2015-11-18 | 广芯电子技术(上海)有限公司 | Audio conversion switching device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |