CN202095048U - Intelligent detection circuit - Google Patents
Intelligent detection circuit Download PDFInfo
- Publication number
- CN202095048U CN202095048U CN2011202229341U CN201120222934U CN202095048U CN 202095048 U CN202095048 U CN 202095048U CN 2011202229341 U CN2011202229341 U CN 2011202229341U CN 201120222934 U CN201120222934 U CN 201120222934U CN 202095048 U CN202095048 U CN 202095048U
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- Prior art keywords
- circuit
- voltage comparator
- intelligent measurement
- resistance
- measurement circuit
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Abstract
The utility model discloses an intelligent detection circuit, which is connected with an SCART interface and a master control chip of a set top box. The intelligent detection circuit comprises a voltage comparator and a voltage reference circuit, wherein a first input end of the voltage comparator is connected with a pin of the SCART interface, wherein the pin is used for providing television state signals, a second input end of the voltage comparator is connected with the voltage reference circuit, and an output end of the voltage comparator is connected with the master control chip. The intelligent detection circuit adopts the voltage comparator to compare signals received from the television with voltage reference signals, thereby detecting work state of the television. The intelligent detection circuit realizes eco SCART intelligent detection, and is simple in circuit structure, low in hardware cost and is in favor of popularization.
Description
Technical field
The utility model relates to the Intelligent Measurement circuit, relates in particular to a kind of Intelligent Measurement circuit that is used for television set top box.
Background technology
Along with popularizing of Digital Television, increasing user uses the set-top box received television signal, passes to television set then and plays.The SCART interface is a kind of audio-video interface of special use, and set-top box uses SCART interface and television set to communicate usually.
For power saving, television set can enter standby mode according to configuration, unless but manipulator top box correspondingly, the set-top box that links to each other with this television set can rest on mode of operation always, thereby has caused the waste of the energy, but also can influence the life-span of set-top box.
At present, some set-top box occurred, had the ecoSCART function, promptly carried out analyzing and processing, and then allowed set-top box change the state of work automatically by the signal that television set is provided, specific as follows:
When TV switched to mode of operation by standby mode, set-top box also automatically switched to mode of operation from standby mode;
When TV switched to standby mode by mode of operation, set-top box also automatically switched to standby mode from mode of operation;
When TV switches to mode of operation by standby mode, and set-top box has been to be in mode of operation before this, and set-top box can be discerned it automatically and be outside (EXT) pattern, continues to keep the mode of operation of set-top box.
But existing ecoSCART Intelligent Measurement circuit structure complexity has higher hardware cost, and is unfavorable for popularizing.
The utility model content
The technical problems to be solved in the utility model is, at ecoSCART Intelligent Measurement circuit structure complexity in the prior art and the higher defective of cost, provides a kind of Intelligent Measurement circuit simple in structure and with low cost.
The technical scheme that its technical problem that solves the utility model adopts is:
A kind of Intelligent Measurement circuit is provided, be connected with main control chip with the SCART interface in the set-top box, described Intelligent Measurement circuit comprises voltage comparator and reference voltage circuit, being used to of the first input end of described voltage comparator and described SCART interface provides the pin of tv state signal to be connected, second input of described voltage comparator is connected with described reference voltage circuit, and the output of described voltage comparator is connected with described main control chip.
In the utility model Intelligent Measurement circuit, the described first input end of described voltage comparator is connected to the pin that is used to provide the tv state signal of described SCART interface by block isolating circuit.
In the utility model Intelligent Measurement circuit, described block isolating circuit comprises capacitance.
In the utility model Intelligent Measurement circuit, also be connected with biasing circuit between the described first input end of described voltage comparator and the described block isolating circuit.
In the utility model Intelligent Measurement circuit, described biasing circuit comprises first resistance and second resistance, one end of described first resistance connects the common port between described first input end and the described block isolating circuit, the other end of described first resistance connects supply voltage, one end of described second resistance connects the described common port between described first input end and the described block isolating circuit, the other end ground connection of described second resistance.
In the utility model Intelligent Measurement circuit, also be connected with rectification circuit between the described first input end of described voltage comparator and the described biasing circuit.
In the utility model Intelligent Measurement circuit, described rectification circuit comprises rectifier diode and commutation capacitor, and the positive pole of described rectifier diode is connected with described biasing circuit, and the negative pole of described rectifier diode is by described commutation capacitor ground connection.
In the utility model Intelligent Measurement circuit, described reference voltage circuit comprises the 3rd resistance and the 4th resistance, the common port of described the 3rd resistance and described the 4th resistance is connected second input of described voltage comparator, the other end of described the 3rd resistance connects described supply voltage, the other end ground connection of described the 4th resistance.
In the utility model Intelligent Measurement circuit, described voltage comparator is IC device LM393.
In the utility model Intelligent Measurement circuit, described rectifier diode is the 1N4148 device of unidirectional conducting.
The beneficial effect of a kind of Intelligent Measurement circuit of the utility model is: adopt voltage comparator to compare from signal and the reference voltage signal that television set receives, thereby detect the operating state of television set, not only realized ecoSCART Intelligent Measurement function, and circuit structure is simple, hardware cost is cheap, helps popularizing.
Description of drawings
The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:
Fig. 1 is the schematic diagram according to the Intelligent Measurement circuit environment of living in of an embodiment of the utility model;
Fig. 2 is the structural representation according to the Intelligent Measurement circuit of an embodiment of the utility model;
Fig. 3 A is the schematic diagram of CVBS (Composite Video Broadcast Signal, composite video signal);
Fig. 3 B is the schematic diagram of blank screen signal;
Fig. 3 C is the schematic diagram of flower screen signal;
Fig. 4 is the circuit diagram according to the Intelligent Measurement circuit that is connected with the SCART interface of an embodiment of the utility model.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
Fig. 1 is the schematic diagram according to the Intelligent Measurement circuit environment of living in of an embodiment of the utility model.As shown in Figure 1, the Intelligent Measurement circuit is connected between SCART interface and the main control chip (CPU), can receive the status signal of representing television set work at present state from television set by the SCART interface, the signal that it received mainly comprises three kinds: well-regulated CVBS signal; Blank screen signal (no signal or have some TVs that just synchronous head signal is provided); And flower screen signal (this moment, we can think the random vision signal less than 100mVpp).Then, the Intelligent Measurement circuit can be judged the work at present state of television set according to the signal that is received, and generates the testing result signal, and the testing result signal is passed to main control chip (CPU), so that main control chip controller top box enters the corresponding work state.
Fig. 2 is the structural representation according to the Intelligent Measurement circuit of an embodiment of the utility model.In the present embodiment, with set-top box in the Intelligent Measurement circuit that is connected with main control chip of SCART interface comprise voltage comparator 110 and reference voltage circuit 120.Being used to of the first input end of voltage comparator 110 and SCART interface provides the pin of television set work at present status signal to be connected, so that receive the status signal (for example CVBS signal, blank screen signal and/or flower screen signal) that is used to represent television set work at present state.Second input of voltage comparator 110 is connected with reference voltage circuit 120, so that receive reference voltage signal from reference voltage circuit 120.The output of voltage comparator is connected with main control chip, so that the comparative result of status signal and reference voltage signal is exported to main control chip, and then makes master signal correspondingly regulate the operating state of set-top box.For example, as shown in Figure 4, voltage comparator 110 can be IC device LM393.
In a preferred embodiment of the present utility model, the first input end of voltage comparator 110 can also be connected to the pin that is used to provide television set work at present status signal (pin 20 for example shown in Figure 4) of SCART interface by block isolating circuit.As shown in Figure 4, block isolating circuit can an electric capacity, for example capacitance C143.By block isolating circuit every straight effect, can avoid effectively and some external interference signals of filtering, and keep the status signal that television set work at present state is represented in comparatively pure being used to.
In a preferred embodiment of the present utility model, also be connected with biasing circuit between the first input end of voltage comparator 110 and the block isolating circuit.For example, as shown in Figure 4, biasing circuit can comprise the first continuous resistance R 180 and second resistance R 181, and the common port A of R180 and R181 inserts between voltage comparator first input end and the block isolating circuit, the other end of R180 connects supply voltage, the other end ground connection of R181.In Fig. 4, biasing circuit can provide a dc offset voltage for status signal to be detected, is about 1.32V (V
A=3.3V*R181/ (R180+R181)=1.32V).
In a preferred embodiment of the present utility model, also be connected with rectification circuit between the first input end of voltage comparator 110 and the biasing circuit.For example, as shown in Figure 4, rectification circuit comprises rectifier diode D11 and commutation capacitor C142.The positive pole of the D11 of rectifier diode is connected with biasing circuit (common port A shown in Figure 4), and the negative pole of rectifier diode D11 is by commutation capacitor C142 ground connection.By the unidirectional conducting effect of D11 diode, and the energy storage effect of capacitor C 142, rectification circuit can partly convert the AC signal of status signal to be detected to direct current signal.The magnitude of voltage that this moment, C was ordered is V
C=V
A-V
D11+ V
TV, V wherein
D11Be the forward conduction voltage of diode D11, V
TVFor status signal to be detected is transformed into voltage behind the direct current signal by AC signal.For example, when rectifier diode D11 adopted the 1N4148 device, its forward conduction voltage was 0.36V～0.38V.Television set current state signal to be detected is through after the processing of foregoing circuit, the voltage of C point generation may for:
1) if normal CVBS signal (mode of operation) as shown in Figure 3A, then V
CVoltage range is at 1.5V～1.7V;
2) if the no signal shown in Fig. 3 B or have only synchronous head signal (blank screen), then V
CVoltage range is at 0.94V～0.99V;
3) if the 150mV noise signal shown in Fig. 3 C (flower screen), then V
CVoltage range is at 1.02～1.04V.
In addition, for example, as shown in Figure 4, reference voltage circuit 120 can comprise the 3rd resistance R 177 and the 4th resistance R 178, the common port of R177 and R178 is connected second input of voltage comparator 110, and the other end of R177 connects supply voltage (being 3.3V among Fig. 4), the other end ground connection of R178.Like this, reference voltage circuit 120 can be 1.32V (V for voltage comparator 110 provides magnitude of voltage
BThe reference voltage signal of=3.3V*R181/ (R180+R181)=1.32V).
As shown in Figure 4, in the course of the work, voltage comparator 110 can compare status signal to be detected and reference voltage signal, is about to V
CAnd V
BNumerical value compare, and comparative result generated testing result signal (for example Veco_scart) export to main control chip, main control chip can be determined the current state of television set according to the testing result signal, whether set-top box is carried out the change of state with decision.Particularly, as voltage V
C＞V
BThe time, represent that this status signal is CVBS, i.e. the current mode of operation that is in of television set, this moment, the output Veco_scart of output of LM393 was a high level; As voltage V
C＜V
BThe time, represent that this status signal is blank screen signal or flower screen signal, i.e. the current standby mode that is in of television set, this moment, the output Veco_scart of output of LM393 was a low level.
To sum up, the Intelligent Measurement circuit that the utility model provides, adopt voltage comparator to compare from status signal and the reference voltage signal that television set receives, for example be no signal or have only synchronous head and output low level during less than the 150mV noise signal at status signal to be detected, and be time output high level greater than 150mV noise signal or well-regulated CVBS signal at status signal to be detected, thereby can detect the operating state of television set effectively, not only realized ecoSCART Intelligent Measurement function, and circuit structure is simple, hardware cost is cheap, helps popularizing.
More than be embodiment more of the present utility model, enumerate these embodiment and only be illustrative purposes for example, and be not used in restriction the utility model.In other embodiment of the present utility model, can comprise the arbitrary characteristics of the present utility model described in the above-mentioned any embodiment and/or the combination in any of these features.And according to embodiment described herein, those skilled in the art know the replacement circuit of various circuit shown in Figure 4.
Though the utility model describes by specific embodiment, it will be appreciated by those skilled in the art that, under the situation that does not break away from the utility model scope, can also carry out various conversion and be equal to alternative the utility model.In addition, at particular condition or material, can make various modifications to the utility model, and not break away from scope of the present utility model.Therefore, the utility model is not limited to disclosed specific embodiment, and should comprise the whole execution modes that fall in the utility model claim scope.
Claims (10)
1. Intelligent Measurement circuit, be connected with main control chip with the SCART interface in the set-top box, it is characterized in that, described Intelligent Measurement circuit comprises voltage comparator and reference voltage circuit, being used to of the first input end of described voltage comparator and described SCART interface provides the pin of tv state signal to be connected, second input of described voltage comparator is connected with described reference voltage circuit, and the output of described voltage comparator is connected with described main control chip.
2. Intelligent Measurement circuit according to claim 1 is characterized in that, the described first input end of described voltage comparator is connected to the pin that is used to provide the tv state signal of described SCART interface by block isolating circuit.
3. Intelligent Measurement circuit according to claim 2 is characterized in that described block isolating circuit comprises capacitance.
4. Intelligent Measurement circuit according to claim 3 is characterized in that, also is connected with biasing circuit between the described first input end of described voltage comparator and the described block isolating circuit.
5. Intelligent Measurement circuit according to claim 4, it is characterized in that, described biasing circuit comprises first resistance and second resistance, one end of described first resistance connects the common port between described first input end and the described block isolating circuit, the other end of described first resistance connects supply voltage, one end of described second resistance connects the described common port between described first input end and the described block isolating circuit, the other end ground connection of described second resistance.
6. Intelligent Measurement circuit according to claim 5 is characterized in that, also is connected with rectification circuit between the described first input end of described voltage comparator and the described biasing circuit.
7. Intelligent Measurement circuit according to claim 6, it is characterized in that, described rectification circuit comprises rectifier diode and commutation capacitor, and the positive pole of described rectifier diode is connected with described biasing circuit, and the negative pole of described rectifier diode is by described commutation capacitor ground connection.
8. Intelligent Measurement circuit according to claim 7, it is characterized in that, described reference voltage circuit comprises the 3rd resistance and the 4th resistance, the common port of described the 3rd resistance and described the 4th resistance is connected second input of described voltage comparator, the other end of described the 3rd resistance connects described supply voltage, the other end ground connection of described the 4th resistance.
9. Intelligent Measurement circuit according to claim 8 is characterized in that, described voltage comparator is IC device LM393.
10. Intelligent Measurement circuit according to claim 9 is characterized in that, described rectifier diode is the 1N4148 device of unidirectional conducting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202229341U CN202095048U (en) | 2011-06-28 | 2011-06-28 | Intelligent detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202229341U CN202095048U (en) | 2011-06-28 | 2011-06-28 | Intelligent detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202095048U true CN202095048U (en) | 2011-12-28 |
Family
ID=45370087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011202229341U Expired - Lifetime CN202095048U (en) | 2011-06-28 | 2011-06-28 | Intelligent detection circuit |
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| Country | Link |
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| CN (1) | CN202095048U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1020459A3 (en) * | 2012-01-16 | 2013-10-01 | Hoste Philip | A SWITCHABLE SOCKET CONTROLLED BY A SET-TOP BOX THAT TURNS THE POWER SUPPLY TO THE TELEVISION DEVICE. |
| CN103414933A (en) * | 2013-07-29 | 2013-11-27 | 华为技术有限公司 | Analog video signal output device and electronic device |
| TWI498572B (en) * | 2013-05-07 | 2015-09-01 | Wistron Corp | Method of automatically detecting the output voltage of the tuner of the dvb-s reception device, adapter and dvb-s reception device |
-
2011
- 2011-06-28 CN CN2011202229341U patent/CN202095048U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1020459A3 (en) * | 2012-01-16 | 2013-10-01 | Hoste Philip | A SWITCHABLE SOCKET CONTROLLED BY A SET-TOP BOX THAT TURNS THE POWER SUPPLY TO THE TELEVISION DEVICE. |
| TWI498572B (en) * | 2013-05-07 | 2015-09-01 | Wistron Corp | Method of automatically detecting the output voltage of the tuner of the dvb-s reception device, adapter and dvb-s reception device |
| CN103414933A (en) * | 2013-07-29 | 2013-11-27 | 华为技术有限公司 | Analog video signal output device and electronic device |
| CN103414933B (en) * | 2013-07-29 | 2016-12-28 | 华为技术有限公司 | Analog video signal output device and electronic equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20111228 |