Signal transmission system and signal transmission method

Patent metadata

Field	Value
Publication number	US-11075541-B2
Application number	US-201816640702-A
Country	US
Kind code	B2
Filing date	Aug 15, 2018
Priority date	Aug 22, 2017
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

A signal transmission system comprises: a power supply, a power sourcing device and a powered device connected to each other through a coaxial cable; the power sourcing device comprises a first active inductor module for receiving a DC signal transmitted by the power supply, and transmitting the DC signal to the powered device through the coaxial cable, a first capacitor module for receiving a superposed signal transmitted through the coaxial cable, and transmitting the superposed signal to a signal processing module; and the powered device comprises a second active inductor module for receiving, through the coaxial cable, the DC signal, and transmitting the DC signal to a signal acquiring module for acquiring a superposed signal, a second capacitor module for transmitting the superposed signal to the power sourcing device through the coaxial cable, and the signal acquiring module is for transmitting the superposed signal to the second capacitor module.

First claim

What is claimed is:

1. A signal transmission system, wherein the signal transmission system is configured to transmit a power signal and a superposed signal, and the signal transmission system comprises:
a power supply, a power sourcing device, and a powered device; wherein the power supply is connected to the power sourcing device, and the power sourcing device is connected to the powered device through a coaxial cable;
wherein the power sourcing device comprises a first active inductor module, a first capacitor module, and a signal processing module connected to the first capacitor module; wherein the first active inductor module is configured to receive a direct current signal transmitted by the power supply, and transmit the direct current signal to the powered device through the coaxial cable; and the first capacitor module is configured to receive a superposed signal transmitted through the coaxial cable, and transmit the superposed signal to the signal processing module;
wherein the powered device comprises a second active inductor module, a second capacitor module, and a signal acquiring module connected to the second capacitor module; wherein the second active inductor module is configured to receive, through the coaxial cable, the direct current signal transmitted by the power sourcing device, and transmit the direct current signal to the signal acquiring module; the signal acquiring module is configured to acquire the superposed signal, and transmit the superposed signal to the second capacitor module; and the second capacitor module is configured to transmit the superposed signal to the power sourcing device through the coaxial cable;
wherein the power sourcing device further comprises a control module and a current detecting module, wherein the control module is configured to control supplying power to the powered device or control stopping supplying power to the powered device; and the current detecting module is configured to receive the direct current signal transmitted by the power supply, and detect the direct current signal;
wherein the current detecting module comprises a first detection resistor, an operational amplifier, a first switch, a second detection resistor, and a sampling module;
wherein the first detection resistor is connected in series between the power supply and the powered device, the first detection resistor is connected in parallel to the operational amplifier, an output terminal of the operational amplifier is connected to the first switch, the first switch is connected to one terminal of the second detection resistor, the second detection resistor is connected in parallel to the sampling module, and the other terminal of the second detection resistor is grounded;
wherein the operational amplifier is configured to acquire a first detection voltage across the first detection resistor, amplify the first detection voltage, and transmit the amplified first detection voltage to the first switch, such that the first switch is switched ON upon acquiring the amplified first detection voltage; and
wherein the sampling module is configured to acquire a second detection voltage across the second detection resistor after the first switch is switched ON and determine a detection current based on the second detection voltage.

2. The signal transmission system according to claim 1 , wherein the power sourcing device further comprises at least one of a first detecting module or a plug detecting module;
wherein the first detecting module is configured to detect an operating parameter of the powered device, and the control module is configured to control a power supply amount to the powered device according to the operating parameter; and
wherein the plug detecting module is configured to detect the superposed signal transmitted by the powered device, and instruct the control module to control stopping supplying power to the powered device when no superposed signal is detected, or the plug detecting module is configured to receive the direct current signal transmitted by the power supply, and instruct the control module to control stopping supplying power to the powered device when the direct current signal is 0.

3. The signal transmission system according to claim 2 , wherein the first detecting module comprises a third detection resistor and a first voltage comparator; wherein
one terminal of the third detection resistor is connected to an output terminal of the power supply, and the other terminal of the third detection resistor is connected to the first voltage comparator and the coaxial cable, respectively;
the third detection resistor and the powered device are configured to divide a voltage supplied by the power supply;
the first voltage comparator is configured to output a comparison result based on a first divided voltage detected at the other terminal of the third detection resistor and a predetermined reference voltage; and
the control module is further configured to determine the operating parameter of the powered device based on the comparison result.

4. The signal transmission system according to claim 2 , wherein the plug detecting module comprises a third voltage comparator and a detection capacitor; wherein
the detection capacitor is connected to the powered device, the detection capacitor is connected to an input terminal of the third voltage comparator, and an output terminal of the third voltage comparator is connected to the control module;
the detection capacitor is configured to receive the superposed signal transmitted by the powered device, and transmit the superposed signal to the third voltage comparator;
when the third voltage comparator receives the superposed signal, the output terminal of the third voltage comparator outputs a first level signal to instruct the control module to control supplying power to the powered device; and
when the third voltage comparator does not receive the superposed signal, the output terminal of the third voltage comparator outputs a second level signal to instruct the control module to control stopping supplying power to the powered device.

5. The signal transmission system according to claim 2 , wherein
the power sourcing device further comprises a protection module, wherein the protection module is configured to control stopping supplying power to the powered device upon detecting that the powered device is short-circuited or the power sourcing device is short-circuited.

6. The signal transmission system according to claim 5 , wherein the protection module comprises a second switch, a fourth detection resistor, a fifth detection resistor, and a second voltage comparator; wherein
the fourth detection resistor and the fifth detection resistor are connected in series between the first active inductor module and the powered device, an input terminal of the second voltage comparator is connected to a first potential point between the fourth detection resistor and the fifth detection resistor, and an output terminal of the second voltage comparator is connected to the second switch;
the fourth detection resistor and the fifth detection resistor are configured to divide a voltage supplied by the power supply;
the second voltage comparator is configured to compare a second divided voltage of the first potential point with a first reference voltage;
when the second divided voltage is greater than the first reference voltage, the second voltage comparator outputs a first level signal to the second switch such that the second switch is closed; and
when the second divided voltage is less than the first reference voltage, the second voltage comparator outputs a second level signal to the second switch such that the second switch is opened.

7. The signal transmission system according to cl

Assignees

• Hangzhou Hikvision Digital Tec

Inventors

• Ye Min
• Luo Mingling
• Zhang Si'En
• Zhang Liang

Classifications

• H02J13/1313 Primary

  using pulsed signals · CPC title

• H02J13/34 Primary

  the equipment being switches, relays or circuit breakers · CPC title

• H02J1/12

  Parallel operation of DC sources having power converters with further DC sources without power converters · CPC title

• H04N7/18

  Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast · CPC title

• H04N7/10

  Adaptations for transmission by electrical cable (H04N7/12 takes precedence) · CPC title