CN205912157U - A circuit for two -wire system visible dialogue system's video signal transmits - Google Patents
A circuit for two -wire system visible dialogue system's video signal transmits Download PDFInfo
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- CN205912157U CN205912157U CN201620018807.2U CN201620018807U CN205912157U CN 205912157 U CN205912157 U CN 205912157U CN 201620018807 U CN201620018807 U CN 201620018807U CN 205912157 U CN205912157 U CN 205912157U
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Abstract
The utility model discloses a circuit for two -wire system visible dialogue system's video signal transmits can effectively balance and uneven switch processing video signal to improve video signal's interference immunity. The utility model provides a pair of a circuit for two -wire system visible dialogue system's video signal transmits, include: be used for first resistance R1 and first electric capacity C1 with the video signal coupling, video signal passes through first resistance R1 and first electric capacity C1 in order, first electric capacity C1's the other end and a common mode inductance T1 are connected.
Description
Technical field
This utility model is related to electronic circuit field, more particularly, to a kind of video letter for two-wire system visual talkback system
Number transmission circuit.
Background technology
In two-wire system visual talkback system, typically adopt transformer-coupled method.Doorway machine is by regarding through ovennodulation
Frequency signal passes through transformer coupled being loaded on two-wire bus；Indoor set passes through transformer coupled taking-up from two-wire bus
Video signal through ovennodulation.
By transformer coupled method although impedance matching and master secondary isolation can preferably be realized, but in bus
Video signal be unbalanced signal it is impossible to eliminate the interference in signal bus transmitting procedure, need machine indoors to increase filtering
Device is filtered to video signal；And transformer-coupled frequency bandwidth is narrow.
It would therefore be highly desirable to provide a kind of video signal transmission circuit that can effectively improve anti-interference.
Utility model content
This utility model provides a kind of circuit of the video signal transmission for two-wire system visual talkback system, Neng Gouyou
Effect is balanced to video signal and uneven conversion process, thus improve video signal anti-interference.
A kind of circuit of video signal transmission for two-wire system visual talkback system that this utility model provides, comprising:
For first resistor r1 that couples video signal and the first electric capacity c1, video signal is sequentially through first resistor r1
With the first electric capacity c1；
The other end of the first electric capacity c1 is connected with the first common mode inductance t1.
Optionally,
It is connected the first bridge heap d1 between first electric capacity c1 and the first common mode inductance t1；
First bridge heap d1 ground connection.
Optionally,
First bridge four diodes of heap d1 bag, the respectively first diode, the second diode, the 3rd diode and the four or two
Pole pipe.
Optionally,
The negative electrode of the first diode is connected with the negative electrode of the second diode, the negative electrode of the 3rd diode and the second diode
Anode connects, and the anode of the 4th diode is connected with the anode of the 3rd diode, the negative electrode of the 4th diode and the first diode
Anode connect.
Optionally,
This circuit also includes the first inductance l1, and inductance l1 is in parallel with first resistor r1 and the first electric capacity c1.
Optionally,
First inductance l1 is connected with the second electric capacity c2, the other end ground connection of the second electric capacity c2.
This utility model additionally provides a kind of doorway machine for two-wire system visual talkback system, installs any of the above-described institute
State the circuit of the video signal transmission for two-wire system visual talkback system；
This circuit is electrically connected with power input 11, speaker and mike 12 and photographic head 13 respectively.
This utility model additionally provides a kind of indoor set for two-wire system visual talkback system, installs any of the above-described institute
State the circuit of the video signal transmission for two-wire system visual talkback system；
This circuit is electrically connected with power output end 21, speaker and mike 22 and display 23 respectively.
This utility model additionally provides one kind and is used for two-wire system visual talkback system, comprising:
Doorway machine 10 and indoor set 20；
Described doorway machine 10 and indoor set 20 all include:
The above-mentioned video signal transmission circuit for two-wire system visual talkback system；
For doorway machine 10 video signal transmission circuit respectively with power input 11, speaker and mike 12 and
Photographic head 13 is electrically connected with；
For indoor set 20 video signal transmission circuit respectively with power output end 21, speaker and mike 22 and
Display 23 is electrically connected with；
Doorway machine 10 is connected by bus 30 with indoor set 20.
Optionally,
Described bus 30 has two.
As can be seen from the above technical solutions, this utility model embodiment has the advantage that
Transmission of video circuit in this utility model includes the resistance and the first electric capacity for coupling video signal, video
Signal is sequentially through this resistance and the first electric capacity；The other end of the first electric capacity and a common mode inductance connection.
Wherein common mode inductance constitutes balun transformator, video signal is balanced-uneven conversion, so that video signal is existed
It is balanced signal on two-wire bus, the anti-interference of enhancing signal.
Brief description
Fig. 1 is a kind of circuit of the video signal transmission for two-wire system visual talkback system in this utility model embodiment
Embodiment electrical block diagram；
Fig. 2 is a kind of balun transformer circuit structural representation in this utility model；
Fig. 3 is the equivalent common-mode signal electrical block diagram in Fig. 2；
Fig. 4 is that in this utility model, one kind is used for two-wire system visual talkback circuit system structural representation.
Specific embodiment
This utility model provides a kind of circuit of the video signal transmission for two-wire system visual talkback system, Neng Gouyou
Effect is balanced to video signal and uneven conversion process, thus improve video signal anti-interference.
Refer to Fig. 1, a kind of video signal transmission for two-wire system visual talkback system in this utility model embodiment
Circuit embodiments, comprising:
For first resistor r1 that couples video signal and the first electric capacity c1, video signal is sequentially through first resistor r1
With the first electric capacity c1；
The other end of the first electric capacity c1 is connected with the first common mode inductance t1.
Wherein common mode inductance constitutes balun transformator, video signal is balanced-uneven conversion, so that video signal is existed
It is balanced signal on two-wire bus, the anti-interference of enhancing signal.
Refer to Fig. 2 to Fig. 4,
When balun transformator is output as uneven video signal ui, ui can be equivalent to common-mode signal ucom and difference
Signal udif is superimposed for mould.
Fig. 2 is the equivalent circuit diagram of the response to difference mode signal udif for the balun transformator.Due to i1=i2, l1=l2=m,
Obtained by Kirchhoff's law:
U1=udif/2-jwl1i1+jwmi2-rc1i1=udif/2-rc1i1； (1-1)
U2=-udif/2+jwl2i2-jwml1+rc2i2=-udif/2+rc2i2； (1-2)
Because rc1, rc2 are much smaller than load rl, rc1, rc2 are negligible, are obtained by formula (1-1), formula (1-2): u1
=udif/2, (1-3)
U2=-udif/2. (1-4)
Fig. 3 is the equivalent circuit of the response to common-mode signal ucom for the balun transformator.Because rc1 be much smaller than rl, and rc1 with
Rl connects, so rc1 is negligible；Obtained by Kirchhoff's law:
Ucom=jwl1i3+jwmi4+i3rl/2； (1-5)
Ucom=jwl2i4+jwmi3+i4rl/2； (1-6)
Because l1=l2=m, rc1=rc2 < < rl, is obtained by formula (1-5), formula (1-6):
U3/ucom=1/ (4jwl1/rl+1)； (1-7)
U4/ucom=1/ (4jwl1/rl+1)； (1-8)
So, when the inductance l of balun transformator meets l > > rl/4w when, the common-mode signal of outfan is close to zero, for
The difference mode signal of outfan is negligible.So uneven video signal can be switched to balance video signal by balun transformator.
Vice versa draws: balance video signal can be switched to uneven video signal by balun transformator.
In this utility model embodiment, a kind of circuit of video signal transmission for two-wire system visual talkback system is implemented
Example further includes:
It is connected the first bridge heap d1 between first electric capacity c1 and the first common mode inductance t1；
First bridge heap d1 ground connection.
Bridge heap is a kind of electronic component, and inside is made up of multiple diodes.Main Function is rectification, adjusts the sense of current.
There are following two beneficial effects with bridge heap rectification, one is convenient, through special arrangement mode so that incoming end segment polarity,
I.e. without the concern for the problem of both positive and negative polarity；Two is that its performance of diode within bridge heap is close, and service behaviour is more stable.
This utility model four diodes of jackshaft heap bag, the respectively first diode, the second diode, the 3rd diode and
4th diode.
Wherein, the negative electrode of the first diode is connected with the negative electrode of the second diode, the negative electrode and the two or two of the 3rd diode
The anode of pole pipe connects, and the anode of the 4th diode is connected with the anode of the 3rd diode, the negative electrode and first of the 4th diode
The anode of diode connects.
In this utility model embodiment, a kind of circuit of video signal transmission for two-wire system visual talkback system is implemented
Example further includes:
This circuit also includes the first inductance l1, and inductance l1 is in parallel with first resistor r1 and the first electric capacity c1.
In this utility model embodiment, a kind of circuit of video signal transmission for two-wire system visual talkback system is implemented
Example further includes:
First inductance l1 is connected with the second electric capacity c2, the other end ground connection of the second electric capacity c2.
This utility model additionally provides a kind of doorway machine for two-wire system visual talkback system, installs any of the above-described institute
State the circuit of the video signal transmission for two-wire system visual talkback system；
This circuit is electrically connected with power input 11, speaker and mike 12 and photographic head 13 respectively.
This utility model additionally provides a kind of indoor set for two-wire system visual talkback system, installs any of the above-described institute
State the circuit of the video signal transmission for two-wire system visual talkback system；
This circuit is electrically connected with power output end 21, speaker and mike 22 and display 23 respectively.
This utility model additionally provides one kind and is used for two-wire system visual talkback system, comprising:
Doorway machine 10 and indoor set 20；
Described doorway machine 10 and indoor set 20 all include:
The above-mentioned video signal transmission circuit for two-wire system visual talkback system；
For doorway machine 10 video signal transmission circuit respectively with power input 11, speaker and mike 12 and
Photographic head 13 is electrically connected with；
For indoor set 20 video signal transmission circuit respectively with power output end 21, speaker and mike 22 and
Display 23 is electrically connected with；
Doorway machine 10 is connected by bus 30 with indoor set 20.
In this utility model embodiment, a kind of circuit of video signal transmission for two-wire system visual talkback system is implemented
Example further includes:
Described bus 30 has two.
Refer to Fig. 2 below, be specifically described for two-wire system visual talkback system to above-mentioned:
Photographic head 13 obtains video signal, and this video signal sequentially passes through 3rd resistor r4 and the 5th electric capacity c5 is coupled to this
In transmission of video circuit, video signal, after the second bridge heap d2 rectification, separates two branch roads, respectively from the 3 of the second bridge heap d2
Pin and the output of 4 pins, enter bus 30 after the second common mode inductance t2.
Wherein, also include the second inductance l2 being connected with power input 11, this second inductance l2 other end and the second bridge
1 pin of heap d2 connects.
This power input 11 is also connected with the 4th electric capacity c4, and the c4 other end is grounded.
3rd electric capacity c3 is in parallel with the 4th electric capacity c4, and the 3rd electric capacity c3 is connected with microphone and speaker 12.
Other end connection the 3rd common mode inductance t3 of bus 30, the other end of the 3rd common mode inductance t3 and the 3rd bridge heap d3's
3rd, 4 pins connect, 2 pin ground connection, and 1 pin is outfan.Wherein, first article of branch road flows through the 3rd inductance l3 and power output end
21 connections；Article 2 branch road, through the 6th electric capacity c6 and 3rd resistor r3, is finally connected with display screen 23.
Wherein, the 7th electric capacity c7 is in parallel with the 8th electric capacity c8, and the c7 other end is grounded.
Those skilled in the art can be understood that, for convenience and simplicity of description, the system of foregoing description,
Device and the specific work process of unit, may be referred to the corresponding process in preceding method embodiment, will not be described here.
It should be understood that disclosed system in several embodiments provided herein, apparatus and method are permissible
Realize by another way.For example, device embodiment described above is only schematically, for example, described unit
Divide, only a kind of division of logic function, actual can have other dividing mode when realizing, for example multiple units or assembly
Can in conjunction with or be desirably integrated into another system, or some features can be ignored, or does not process.Another, shown or
The coupling each other discussing or direct-coupling or communication connection can be by some interfaces, the indirect coupling of device or unit
Close or communicate to connect, can be electrical, mechanical or other forms.
The described unit illustrating as separating component can be or may not be physically separate, show as unit
The part showing can be or may not be physical location, you can with positioned at a place, or can also be distributed to multiple
On NE.The mesh to realize this embodiment scheme for some or all of unit therein can be selected according to the actual needs
's.
In addition, can be integrated in a processing unit in each functional unit in each embodiment of this utility model,
Can be that unit is individually physically present it is also possible to two or more units are integrated in a unit.Above-mentioned integrated
Unit both can be to be realized in the form of hardware, it would however also be possible to employ the form of SFU software functional unit is realized.
If described integrated unit is realized and as independent production marketing or use using in the form of SFU software functional unit
When, can be stored in a computer read/write memory medium.Based on such understanding, the technical solution of the utility model is originally
The part in other words prior art being contributed in matter or all or part of this technical scheme can be with software products
Form embodies, and this computer software product is stored in a storage medium, including some instructions with so that one is counted
Calculate described in machine equipment (can be personal computer, server, or network equipment etc.) execution each embodiment of this utility model
The all or part of step of method.And aforesaid storage medium includes: u disk, portable hard drive, read only memory (rom, read-
Only memory), random access memory (ram, random access memory), magnetic disc or CD etc. various permissible
The medium of store program codes.
The above, above example only in order to the technical solution of the utility model to be described, is not intended to limit；Although ginseng
According to previous embodiment, this utility model is described in detail, it will be understood by those within the art that: it is still
Technical scheme described in foregoing embodiments can be modified, or wherein some technical characteristics are carried out with equivalent replacing
Change；And these modifications or replacement, do not make the essence of appropriate technical solution depart from this utility model each embodiment technical scheme
Spirit and scope.
Claims (10)
1. a kind of circuit of the video signal transmission for two-wire system visual talkback system is it is characterised in that include:
For the first resistor (r1) that couples video signal and the first electric capacity (c1), video signal is sequentially through the described first electricity
Resistance (r1) and the first electric capacity (c1)；
The other end of described first electric capacity (c1) is connected with the first common mode inductance (t1).
2. the circuit of the video signal transmission for two-wire system visual talkback system according to claim 1, its feature exists
In,
It is connected the first bridge heap (d1) between described first electric capacity (c1) and described first common mode inductance (t1)；
Described first bridge heap (d1) ground connection.
3. the circuit of the video signal transmission for two-wire system visual talkback system according to claim 2, its feature exists
In,
Described first bridge heap (d1) wraps four diodes, the respectively first diode, the second diode, the 3rd diode and the 4th
Diode.
4. the circuit of the video signal transmission for two-wire system visual talkback system according to claim 3, its feature exists
In,
The negative electrode of described first diode is connected with the negative electrode of described second diode, the negative electrode of described 3rd diode with described
The anode of the second diode connects, and the anode of described 4th diode is connected with the anode of described 3rd diode, and the described 4th
The negative electrode of diode is connected with the anode of described first diode.
5. the circuit of the video signal transmission for two-wire system visual talkback system according to claim 1, its feature exists
In,
Described circuit also includes the first inductance (l1), described inductance (l1) and described first resistor (r1) and the first electric capacity (c1) and
Connection.
6. the circuit of the video signal transmission for two-wire system visual talkback system according to claim 5, its feature exists
In,
Described first inductance (l1) is connected with the second electric capacity (c2), the other end ground connection of described second electric capacity (c2).
7. a kind of doorway machine for two-wire system visual talkback system is it is characterised in that install as arbitrary in claim 1 to 6
Circuit described in；
Described circuit is electrically connected with power input (11), speaker and mike (12) and photographic head (13) respectively.
8. a kind of indoor set for two-wire system visual talkback system is it is characterised in that install as arbitrary in claim 1 to 6
Circuit described in；
Described circuit is electrically connected with power output end (21), speaker and mike (22) and display (23) respectively.
9. one kind is used for two-wire system visual talkback system it is characterised in that including:
Doorway machine (10) and indoor set (20)；
Described doorway machine (10) and indoor set (20) all include:
Circuit as any one of claim 1 to 6；
For doorway machine (10) described circuit respectively with power input (11), speaker and mike (12) and photographic head
(13) it is electrically connected with；
For indoor set (20) described circuit respectively with power output end (21), speaker and mike (22) and display
(23) it is electrically connected with；
Described doorway machine (10) is connected by bus (30) with indoor set (20).
10. according to claim 9 for two-wire system visual talkback system it is characterised in that
Described bus (30) has two.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018807.2U CN205912157U (en) | 2016-01-06 | 2016-01-06 | A circuit for two -wire system visible dialogue system's video signal transmits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018807.2U CN205912157U (en) | 2016-01-06 | 2016-01-06 | A circuit for two -wire system visible dialogue system's video signal transmits |
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| Publication Number | Publication Date |
|---|---|
| CN205912157U true CN205912157U (en) | 2017-01-25 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201620018807.2U Active CN205912157U (en) | 2016-01-06 | 2016-01-06 | A circuit for two -wire system visible dialogue system's video signal transmits |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105472295A (en) * | 2016-01-06 | 2016-04-06 | 广州视声智能科技有限公司 | Circuit for transmitting video signal of two-wire system video door phone system |
| CN110277619A (en) * | 2019-06-18 | 2019-09-24 | 深圳振华富电子有限公司 | Balun transformer |
-
2016
- 2016-01-06 CN CN201620018807.2U patent/CN205912157U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105472295A (en) * | 2016-01-06 | 2016-04-06 | 广州视声智能科技有限公司 | Circuit for transmitting video signal of two-wire system video door phone system |
| CN110277619A (en) * | 2019-06-18 | 2019-09-24 | 深圳振华富电子有限公司 | Balun transformer |
| CN110277619B (en) * | 2019-06-18 | 2024-01-19 | 深圳振华富电子有限公司 | Balun transformer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 510730 Guangdong province Guangzhou city four street bluejade Guangzhou economic and Technological Development Zone No. nine, No. 6 Building 601 room Patentee after: Guangzhou visual sound intelligent technology Co.,Ltd. Address before: 510730 Guangdong province Guangzhou city four street bluejade Guangzhou economic and Technological Development Zone No. nine, No. 6 Building 601 room Patentee before: GUANGZHOU VIDEO-STAR ELECTRONICS Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 510730 Room 601, plant 6, No. 9, Lanyu 4th Street, Guangzhou Economic and Technological Development Zone, Guangzhou, Guangdong Province Patentee after: GUANGZHOU VIDEO-STAR ELECTRONICS Co.,Ltd. Address before: 510730 Room 601, plant 6, No. 9, Lanyu 4th Street, Guangzhou Economic and Technological Development Zone, Guangzhou, Guangdong Province Patentee before: Guangzhou visual sound intelligent technology Co.,Ltd. |
|
| CP01 | Change in the name or title of a patent holder |