CN101527450A - Protective device for video transmission - Google Patents
Protective device for video transmission Download PDFInfo
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- CN101527450A CN101527450A CN200910116514A CN200910116514A CN101527450A CN 101527450 A CN101527450 A CN 101527450A CN 200910116514 A CN200910116514 A CN 200910116514A CN 200910116514 A CN200910116514 A CN 200910116514A CN 101527450 A CN101527450 A CN 101527450A
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- diode
- video
- protective device
- diodes
- video transmission
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Abstract
The invention relates to a protective device for video transmission. The protective device comprises four diodes; and every two diodes are in series connection in the same direction and then in inverse parallel connection. The four diodes which are in series connection in the same direction and then in inverse parallel connection by every two diodes are adopted to form a two-way pressure drop protective device; and when a video input terminal and/or a video output terminal of protected equipment is mistakenly connected with AC and DC supply, the protected equipment is clamped within lower voltage range by the protective device, thus being capable of effectively preventing damaging the protected equipment as the video input terminal or the video output terminal of the protected equipment is mistakenly connected with the AC and the DC supply.
Description
Technical field
The present invention relates to the video protection technology, especially a kind of protective device that is used for video transmission.
Background technology
Traditional video protection adopts the PPTC over-current protecting element usually; folding is formula surge suppressor and transient voltage inhibition TVS diode also; these components and parts have two-way or unidirectional two kinds; the Current Regulation ability is strong; the real reaction time is fast; can only arrive 5.8V yet the operating voltage of these components and parts is minimum; and the junction capacitance that produces has the effect of bypass to video; especially parasitic junction capacitance reaches tens of PF to hundred PF usually on the PN junction of transient voltage inhibition TVS diode; the high fdrequency component of the vision signal that decayed; image definition is descended; the edge has a common boundary fuzzy; the quality of loss vision signal has very big influence to video bandwidth.In addition, these protect costing an arm and a leg of components and parts, and participation protective also has gas discharge tube simultaneously, piezo-resistance, and gas discharge tube, the response speed of piezo-resistance is slower, and conducting voltage is bigger, and the protection reliability is relatively poor.
At present, at the construction field (site), if alterating and direct current is gone in the video inputs of video equipment or video output terminals misconnection, even the time of inserting is very short, sometimes between a few tens of milliseconds arrives several milliseconds, but the damage that operation must cause video equipment is gone in this misconnection, and in actual mechanical process, it is comparatively general that phenomenon is gone in this misconnection.
Summary of the invention
The object of the present invention is to provide a kind of protective device that is used for video transmission, the cost of this protective device is low, can prevent effectively that going into alterating and direct current because of the video inputs of protected equipment or the misconnection of video output terminals short time damages protected equipment.
For achieving the above object, a kind of protective device that is used for video transmission provided by the invention, this device comprises four diodes, four diodes are reverse parallel connection again after the series aiding connection in twos.
The present invention adopts in twos series aiding connection four diodes of reverse parallel connection again; constitute two-way pressure drop protective device; when alterating and direct current is gone in misconnection on the video inputs of protected equipment and/or the video output terminals; in lower voltage range, can effectively prevent that going into alterating and direct current because of the video inputs of protected equipment or the misconnection of video output terminals short time damages protected equipment by clamper of the present invention.
Description of drawings
Fig. 1 is a circuit diagram of the present invention.
Embodiment
A kind of protective device that is used for video transmission; this device comprises four diodes, and four diodes are reverse parallel connection again after the series aiding connection in twos, and this device is connected on the video inputs and/or video output terminals of protected equipment; protected equipment is video equipment, as shown in Figure 1.The present invention can be applied to industrial monitoring camera video input, the input of cable system video and output, other video switching apparatus and input of video distribution system video and output.
In conjunction with Fig. 1, described four diodes are first, second, third and fourth diode D1, D2, D3, D4, the first diode D1 connects with the second diode D2, the positive pole of the first diode D1 connects the negative pole of the second diode D2, the 3rd diode D3 connects with the 4th diode D4, the positive pole of the 3rd diode D3 connects the negative pole of the 4th diode D4, and the positive pole of the second diode D2 connects the positive pole of the 3rd diode D3, and the negative pole of the first diode D1 connects the positive pole of the 4th diode D4.Draw terminals A between described first diode D1 and the 4th diode D4, draw terminals B between described second diode D2 and the 3rd diode D3, terminals A, B are attempted by on the video inputs and/or video output terminals of protected equipment.As seen; this device can be connected on the video inputs of protected equipment; also can be connected on the video output terminals of protected equipment; at the video inputs of protected equipment or output when alternating current or direct current are gone in the short time misconnection; can avoid effectively protected equipment is caused damage; here, the short time was meant in three minutes.
In conjunction with Fig. 1; described four diodes are silicone tube; the forward voltage drop of each diode is between 0.7V and 1.5V; in the present invention; the forward voltage drop of each diode is 1.1V; forward and reverse pressure drop of this device is 2.2V so, thereby makes in the scope of voltage clamp about 2.2V of the video inputs of connected protected equipment or video output terminals, and the alterating and direct current that misconnection is gone into can't exert an influence to video equipment at short notice.Therefore, the video inputs of protected equipment or video output terminals misconnection are gone under alternating current or the galvanic situation at short notice, can avoid burning out video equipment by the present invention, thereby play the purpose of protective circuit.In addition, the maximum of the junction capacitance of each diode is 10PF, if junction capacitance is big, will cause video bandwidth to diminish, and influences the video transmission effect, and junction capacitance of the present invention has been avoided video bandwidth is impacted less than 10PF.
The present invention is further illustrated below in conjunction with Fig. 1.
With protected equipment one video camera is example; terminals A of the present invention, B are attempted by on the video inputs of video camera; the interchange of impact 24V to 36V or DC power supply on the video inputs of video camera; insert several seconds to tens seconds; video disappears; and then disconnect, the video of video camera shows normal.220V is exchanged again and seal in a 60W bulb, be connected with video inputs, the 60W bulb is shinny, and video disappears, and disconnects 220V after several seconds to tens seconds and exchanges, and the video recovery of video camera is normal.The present invention is used for the video balance transmission physical circuit that chip operating voltage is 5V, can also plays the effect of protection chip.
In sum; core of the present invention be to utilize with series aiding connection in twos again four diodes of reverse parallel connection constitute two-way pressure drop protective device; when the video inputs of video equipment or video output terminals are gone into interchange or direct current in the short time misconnection, can effectively avoid video equipment is caused damage.Simultaneously, the junction capacitance of this protective device is less, has avoided video bandwidth is impacted.
Claims (8)
1, a kind of protective device that is used for video transmission is characterized in that: this device comprises four diodes, and four diodes are reverse parallel connection again after the series aiding connection in twos.
2, the protective device that is used for video transmission according to claim 1 is characterized in that: this device is connected on the video inputs and/or video output terminals of protected equipment.
3, the protective device that is used for video transmission according to claim 1; it is characterized in that: described four diodes are first, second, third and fourth diode D1, D2, D3, D4; the first diode D1 connects with the second diode D2; the positive pole of the first diode D1 connects the negative pole of the second diode D2; the 3rd diode D3 connects with the 4th diode D4; the positive pole of the 3rd diode D3 connects the negative pole of the 4th diode D4; the positive pole of the second diode D2 connects the positive pole of the 3rd diode D3, and the negative pole of the first diode D1 connects the positive pole of the 4th diode D4.
4, the protective device that is used for video transmission according to claim 1 is characterized in that: described four diodes are silicone tube, and the forward voltage drop of each diode is between 0.7V and 1.5V, and the maximum of the junction capacitance of each diode is 10PF.
5, the protective device that is used for video transmission according to claim 1 is characterized in that: described protected equipment is video equipment.
6, the protective device that is used for video transmission according to claim 3 is characterized in that: draw terminals A between described first diode D1 and the 4th diode D4, draw terminals B between described second diode D2 and the 3rd diode D3.
7, the protective device that is used for video transmission according to claim 4 is characterized in that: the forward voltage drop of described each diode is 1.1V.
8, the protective device that is used for video transmission according to claim 6 is characterized in that: described terminals A, B are attempted by on the video inputs and/or video output terminals of protected equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910116514A CN101527450A (en) | 2009-04-10 | 2009-04-10 | Protective device for video transmission |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910116514A CN101527450A (en) | 2009-04-10 | 2009-04-10 | Protective device for video transmission |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101527450A true CN101527450A (en) | 2009-09-09 |
Family
ID=41095191
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910116514A Pending CN101527450A (en) | 2009-04-10 | 2009-04-10 | Protective device for video transmission |
Country Status (1)
| Country | Link |
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| CN (1) | CN101527450A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102340645A (en) * | 2011-08-01 | 2012-02-01 | 北京彩讯科技股份有限公司 | Clamping protection circuit of analog high-definition video interface |
| CN103279057A (en) * | 2013-04-28 | 2013-09-04 | 许昌许继晶锐科技有限公司 | Analog acquisition channel protection circuit and analog acquisition system |
| CN106060436A (en) * | 2016-03-28 | 2016-10-26 | 乐视控股（北京）有限公司 | Video output method, video output circuit and multimedia terminal |
| CN110444537A (en) * | 2019-08-29 | 2019-11-12 | 中国振华集团永光电子有限公司（国营第八七三厂） | A kind of ceramic paster encapsulates the design method of two-way low junction capacity TVS diode |
| CN111742618A (en) * | 2018-02-28 | 2020-10-02 | 赤多尼科两合股份有限公司 | Ripple suppression circuit, control method and driving apparatus |
-
2009
- 2009-04-10 CN CN200910116514A patent/CN101527450A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102340645A (en) * | 2011-08-01 | 2012-02-01 | 北京彩讯科技股份有限公司 | Clamping protection circuit of analog high-definition video interface |
| CN102340645B (en) * | 2011-08-01 | 2015-08-05 | 北京彩讯科技股份有限公司 | Clamping protection circuit of analog high-definition video interface |
| CN103279057A (en) * | 2013-04-28 | 2013-09-04 | 许昌许继晶锐科技有限公司 | Analog acquisition channel protection circuit and analog acquisition system |
| CN103279057B (en) * | 2013-04-28 | 2018-09-07 | 许昌许继晶锐科技有限公司 | Analog acquisition passage protects circuit and analog collection system |
| CN106060436A (en) * | 2016-03-28 | 2016-10-26 | 乐视控股（北京）有限公司 | Video output method, video output circuit and multimedia terminal |
| CN111742618A (en) * | 2018-02-28 | 2020-10-02 | 赤多尼科两合股份有限公司 | Ripple suppression circuit, control method and driving apparatus |
| CN110444537A (en) * | 2019-08-29 | 2019-11-12 | 中国振华集团永光电子有限公司（国营第八七三厂） | A kind of ceramic paster encapsulates the design method of two-way low junction capacity TVS diode |
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| C06 | Publication | ||
| PB01 | Publication | ||
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| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Open date: 20090909 |