Supercharge Your Innovation With Domain-Expert AI Agents!

Method for preventing illegal signals from intruding cable TV network

A cable TV network and illegal signal technology, which is applied in the field of power supply or amplifier power on and off, can solve the problem of no method or device for detecting and preventing illegal signals from invading the cable TV network

Inactive Publication Date: 2002-12-25
黄志斌 +1
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

sometimes with dire consequences
However, no method or device for preventing illegal signals from intruding into the cable TV network has been found through patent information retrieval.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preventing illegal signals from intruding cable TV network
  • Method for preventing illegal signals from intruding cable TV network
  • Method for preventing illegal signals from intruding cable TV network

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Example 1, see figure 2 , image 3 , Figure 4 . The method of using audio signal and demodulating by CXM1019 FM. The full TV signal is a vestigial sideband AM signal. at image carrier frequency f 1 The upper 6.5MHz is the sound FM carrier frequency f 2 , Image-sound carrier power ratio V / A is 17±3db. The applicant actually measured the differences of the three local sampling channels DS-1, DS-2, and DS-3 as 15db, 15db, and 14db. There are three demodulators 1, 2, and 3. As long as one of the three demodulators has a normal input signal, it is considered to have a normal transmission signal. This design improves reliability. In fact, it can also work when there is only one demodulator.

[0015] exist Figure 4 , the sampling gating circuit 1-1 consists of C 1 、C 2 、C 3 、C 4 、C 5 and L 1 , L 2 Composition, connected to the pre-stage signal delivered by the cable TV network and the 12 pins of CXM1019. In this circuit, C 2 , L 1 One end of the parallel ...

Embodiment 2

[0017] Embodiment 2, an FM pilot signal is sent by the FM signal generator at the front end, and the signal of the local oscillator circuit is mixed with it to generate an intermediate frequency of 10.7 MHz, which is then detected and output from pin 19. At this time, the frequency of the FM pilot signal is controlled by very few people, which is more secure than Embodiment 1. Crystal Oscillator CF 0 Its fundamental frequency value should be customized according to the frequency of the FM pilot signal.

Embodiment 3

[0018] In Embodiment 3, the front end sends one or more FM signals through an FM modulator, and its principle and effect are similar to Embodiment 2.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The present invention relates to a method for preventing illegal signal from invading the cable TV network. When there is no normal transmission signal in the cable main line, the power source, whichsupplies the supplier or / and amplifier, will be switched off automatically. When there is normal transmission signal in the cable main line, the power source will be switched on automatically. There are the frequency modulated aural signal, or the frequency modulated pilot signal generated by the frequency-modulated signal generator or the frequency modulated signal sent by the frequency-modulated modulator in the composite television signal sent from the front end of the cable TV. With the above said signals being demodulated, the signal is as the control signal for switching on / off the power source. The invention preventing illegal signal from invading the cable TV network that causes serious results possibly.

Description

technical field [0001] The invention belongs to the category of image communication in the International Patent Classification, and particularly relates to a method for controlling the on-off power supply of a power supply or an amplifier in a CATV network by using a frequency modulation signal sent by a cable TV front end. Background technique [0002] In the cable TV network technology, the operator usually sends the optical signal from the optical cable to the optical receiver, and then sends the full TV signal and FM broadcast signal of several channels through the trunk cable, trunk amplifier, branch cable, and user amplifier. user. Said network includes optical cable, main line and branch line of cable, power supply and amplifier thereof. When the optical path fails, that is, when the optical receiver has no signal output, the post-stage amplifier is in a no-signal working state; the front-stage power supply is powered off or the transmission network between the front...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H04N7/10H04N7/54
Inventor 黄志斌李毓新
Owner 黄志斌
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com