CN101442638B - Protection method and circuit for television airdrome - Google Patents
Protection method and circuit for television airdrome Download PDFInfo
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- CN101442638B CN101442638B CN2008101832245A CN200810183224A CN101442638B CN 101442638 B CN101442638 B CN 101442638B CN 2008101832245 A CN2008101832245 A CN 2008101832245A CN 200810183224 A CN200810183224 A CN 200810183224A CN 101442638 B CN101442638 B CN 101442638B
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- 230000004224 protection Effects 0.000 title claims abstract description 34
- 238000000034 method Methods 0.000 title claims abstract description 32
- 230000001681 protective effect Effects 0.000 claims abstract description 37
- 239000003990 capacitor Substances 0.000 claims description 15
- 238000001514 detection method Methods 0.000 claims description 13
- 238000001914 filtration Methods 0.000 claims description 5
- 238000005086 pumping Methods 0.000 claims description 5
- 230000035484 reaction time Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001684 chronic effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
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Abstract
The invention provides a method for field protection of a television and a circuit thereof. The method comprises the following steps: acquiring detecting voltage of a field protective circuit; uniformly converting the detecting voltage together with detecting voltage of other protective circuits set in the television into a signal with up and down variations, and transmitting the signal to an I/O port of a micro control unit MCU; and stopping operation of a program and closing external equipment to make a machine enter a standby state, when the MCU identifies a low level signal on the I/O port. The method is to convert the field protection of the television into a voltage mode, and the field protective circuit can be reflected on the I/O port with other protective circuits in the circuit in the voltage mode, thereby simplifying determination of the MCU, saving I/O port resource of the MCU, and reducing time spent on protecting determination.
Description
Technical field
The present invention relates to television technologies, particularly a kind of television airdrome guard method and circuit.
Background technology
If the television set field circuit is direct current output, need a band protective circuit, in case because field circuit damages, can make the heating of picture tube deflecting coil and burn out, protect so must carry out field.Prior art can have following method on using:
1, obtains vertical blanking impulse by field circuit and deliver on the I/O mouth of micro-control unit (Micro Controller Unit, MCU), by MCU identification, just protect in case pulse disappears.This scheme needs MCU constantly to monitor pulse signal on the pin, carries out identification and the judgement of high-low level, and it is more that this scheme takies time of MCU.As shown in Figure 1, obtained vertical blanking impulse and delivered on the I/O mouth of MCU by field circuit, by MCU identification, just protect in case pulse disappears, the method takies the I/O mouth of more MCU, and software program is complicated.
2, obtain vertical blanking impulse by field circuit, feed back to the scan process chip, MCU constantly inquires about the register of rear-end scanning process chip by the I2C bus, obtains the field circuit work state information, in case field circuit work is undesired, implements immediately protection.As shown in Figure 2, obtain vertical blanking impulse by field circuit, feed back to the scan process chip, MCU obtains the field circuit work state information by the register of continuous inquiry scan process chip, in case field circuit work is undesired, implements immediately protection.But this scheme needs MCU constantly to inquire about buffer status in the main program circulation, and other protections also will be inquired about in adding circuit, also will spend many times.
Television set generally has protective circuit; for example beam electronic current protection; the voltage short-circuit protection, X ray protection, a protection often are processed into high-low level to protection through testing circuit on processing of circuit; then deliver to the I/O mouth of MCU; take again safeguard measure by the judgement high-low level, and pulse mode is often adopted in the protection of field circuit, because vertical blanking impulse is easy to obtain; process through just can directly being sent to MCU behind the amplitude-limiting circuit, perhaps deliver to the rear-end scanning process chip.
Along with the reduction of television set cost and the raising of integrated circuit integrated level; the resource of chip pin is nervous all the more; the I/O mouth is fewer; to above-mentioned said protection; be sent to MCU to high-low level carries out level detection on the one hand; again vertical blanking impulse is sent to the rear-end scanning chip on the one hand; if but the I/O mouth that back-end chip does not support a defencive function just can only be sent to MCU detects; so MCU should detect high-low level; detect again the pulse signal on the I/O mouth; make protection problem many places take the running time of MCU, efficient is lower.
Summary of the invention
The object of the invention is to, a kind of television airdrome guard method is provided.
Another object of the present invention is to, a kind of television airdrome protective circuit is provided.
Television airdrome guard method of the present invention; obtain the detection voltage of a protective circuit; and be converted to the I/O mouth that signal that a height changes is sent to micro-control unit MCU together with the detection voltage unification of other protective circuit that arranges in the television set; when MCU recognizes low level signal on the I/O mouth; then shut down procedure operation; close external equipment, make machine enter holding state.
Wherein, other protective circuit that arranges in the described television set comprises: beam electronic current restriction ABL beam electronic current protective circuit, load short-circuit protection circuit, X ray protective circuit etc.
Wherein, the described detection voltage that obtains a protective circuit comprises the following steps: that obtaining the field from the pumping source capacitance terminal of field IC disappears after the cloudy pulse; through capacitance C2 after straight; meet over the ground differential resistance R4 and fly-wheel diode VD2; fly-wheel diode VD2 plus earth; negative pole connects the common port of rectifier diode VD1 and capacitance C2; obtain differential signal voltage at differential resistance R4; the filter capacitor C1 filtering that rectifier diode VD1 through connecting and rectifier diode negative pole connect obtains described detection voltage.
Wherein, if described other protective circuit is working properly, does not trigger and enter guard mode, triode V2 collector electrode output high level.
Television airdrome protective circuit of the present invention; wherein; the field disappear cloudy pulse through capacitance C2 after straight; meet over the ground differential resistance R4 and fly-wheel diode VD2; fly-wheel diode VD2 plus earth, negative pole connects the common port of rectifier diode VD1 and capacitance C2, obtains differential signal voltage at differential resistance R4; the filter capacitor C1 filtering that rectifier diode VD1 through connecting and rectifier diode negative pole connect obtains direct voltage.
Wherein, described the pumping source capacitance terminal acquisition of cloudy pulse by field IC that disappear.
The invention has the beneficial effects as follows: according to television airdrome guard method of the present invention and circuit; the television airdrome protection is converted to voltage form; can with circuit in ABL beam electronic current protection; the load short circuits protection; X ray protection etc. all is reflected on the I/O mouth with voltage form; simplified the judgement of MCU; saved the I/O mouth resource of MCU; also reduce MCU and judged the time that spends in protection; in addition also will be hurry up than pulse mode on the reaction time at circuit; in a word, the present invention has simplified Software for Design, has improved the MCU operating efficiency.
Description of drawings
Fig. 1 is existingly obtained vertical blanking impulse and is delivered to the I/O mouth schematic diagram of MCU by field circuit;
Fig. 2 existingly obtains vertical blanking impulse by field circuit and feeds back to scan process chip schematic diagram;
Fig. 3 is television airdrome protective circuit schematic diagram of the present invention;
Fig. 4 is a contrast oscillogram of guard method of the present invention and prior art;
Fig. 5 is another contrast oscillogram of guard method of the present invention and prior art;
Fig. 6 is the another contrast oscillogram of guard method of the present invention and prior art.
Embodiment
Below, 1～6 describe television airdrome guard method of the present invention and circuit in detail with reference to the accompanying drawings.
Core concept of the present invention is: protect pulse mode to be converted to voltage system the field; then the detection voltage in the circuit is sent to MCU with the signal that other protective circuits detection voltage unifications are converted to a height variation; because technical scheme of the present invention only accounts for I/O mouth of MCU; saved the chip pin resource; take less again MCU running time, improve the operating efficiency of MCU.
As shown in Figure 3, the field disappears cloudy pulse can be by the pumping source capacitance terminal acquisition of field IC, through capacitance C2 after straight, meet over the ground differential resistance R4 and fly-wheel diode VD2, fly-wheel diode VD2 plus earth, negative pole connects the common port of VD1 and C2, obtains differential signal voltage in resistance R 4, the filter capacitor C1 filtering that rectifier diode VD1 through connecting and rectifier diode negative pole connect obtains direct voltage.If electric capacity does not have load after tested, voltage can reach 27.8V, adds that voltage was 1.29V when 60HZ voltage was 0.98V, 100HZ after the load, is saw chi waveform attitude, and when cloudy pulse only has pulse to arrive because the field disappears voltage, pulse duration being arranged just is about 200uS; And 60HZ cycle 16.67MS, 100HZ cycle 10MS, capacitor discharge time relative pulse width is chronic.Filter capacitor C1 most of time is discharge condition.Meet current-limiting resistance R3 to the base stage of triode V1 in filter capacitor C1 back, the while transistor base also meets shunt resistance R2 transistor base is shunted.
The protective circuit operation principle is as follows: when field circuit works; disappear cloudy pulse of field obtains voltage through rectifies at filter capacitor C1; and make triode V1 saturation conduction; make triode V1 collector electrode output low level; can't make diode VD2 conducting, other protective circuits are not exerted an influence.If other protective circuits (such as the protection of ABL beam electronic current, the circuit such as X ray protection) are working properly, do not trigger and enter guard mode, triode V2 collector electrode output high level.When MCU recognizes signal on the I/O mouth and is high level, allow machine normally move.
When vertical output circuit work is undesired, disappear cloudy pulse of field disappears, electric charge on the filter capacitor C1 exhausted through the very short time, so triode V1 can't conducting, triode V1 collector electrode output high level, make diode VD2 conducting work, and then make triode V2 saturation conduction, triode V2 collector electrode output low level.When MCU recognizes low level signal on the I/O mouth, external equipment is closed in immediately shut down procedure operation, makes machine enter holding state, and the user can't be by the button on the machine front panel or remote controller start, and namely machine enters the Protection state.
Voltage on the filter capacitor C1 is sent to the V1 base stage through R3, and electric current can reach 0.37 milliampere, the low level of triode V1 stable output when making normal operation.The parameter of R3 is very crucial in the circuit, and resistance is large, and a start protective circuit is long settling time, and the shutdown protective reaction time is also long, must suitably reduce the R3 resistance value, and under the condition of start V1 working stability, the assurance field protective circuit reaction time is shorter as much as possible.
The circuit reaction time is faster than pulse mode after tested.As shown in Figure 4, the pulse mode reaction time when waveform is normal after the chi pulses punching of 3 saws.Horizontal coordinate is the time, and 20 milliseconds of sweep times, vertical coordinate is voltage, the unit volt.Waveform is to measure with the 100:1 voltage probe.After adopting this programme, as shown in Figure 5, horizontal coordinate is the time after the punching of 2 saw chi pulses the reaction time after tested, and 40 milliseconds of sweep times, vertical coordinate is voltage, the unit volt.Waveform is to measure with the 100:1 voltage probe.
When field circuit broke down, field pulse disappeared, and the electric charge on the C1 electric capacity is reduced rapidly, finally makes V1 withdraw from saturation condition, so the I/O mouth state of MCU reverses, makes complete machine enter guard mode.As shown in Figure 6, horizontal coordinate is the time, and 40 milliseconds of sweep times, vertical coordinate is voltage, the unit volt.Waveform is to measure with the 100:1 voltage probe.Because C1 corresponding to fault point may be in discharge, also may be in charging, so the reaction time is fixing, the process test is between 30-40mS, and the general employing voltage field protection scheme circuit reaction time is at least more than 300mS.In addition since the rear-end scanning process chip not simultaneously, the reaction time of circuit also can change to some extent, must reach promising result according to the parameter in the continuous debug circuit of physical circuit.
In sum; according to television airdrome guard method of the present invention and circuit; the television airdrome protection is converted to voltage form; can with circuit in ABL beam electronic current protection; the load short circuits protection; X ray protection; a protection all is reflected on the I/O mouth with voltage form; simplified the judgement of MCU, saved the I/O mouth resource of MCU has also reduced the time of MCU in protection judgement cost; in addition also will be hurry up than pulse mode on the reaction time at circuit; in a word, the present invention has simplified Software for Design, has improved the MCU operating efficiency.
More than be in order to make those of ordinary skills understand the present invention; and the detailed description that the present invention is carried out; but can expect; within not breaking away from the scope that claim of the present invention contains, can also make other changes and modifications, these variations and revising all in protection scope of the present invention.
Claims (4)
1. television airdrome guard method, it is characterized in that, obtain the detection voltage of a protective circuit, and be converted to the I/O mouth that a high-low level signal is sent to micro-control unit MCU together with the detection voltage unification of other protective circuit that arranges in the television set, when MCU recognizes low level signal on the I/O mouth, external equipment is closed in then shut down procedure operation, makes machine enter holding state; Wherein, the detection voltage that obtains a protective circuit comprises the following steps: behind the pumping source capacitance terminal acquisition vertical blanking impulse of field IC, through capacitance C2 after straight, meet over the ground differential resistance R4 and fly-wheel diode VD3, fly-wheel diode VD3 plus earth, negative pole connects the common port of rectifier diode VD1 and capacitance C2, obtain differential signal voltage at differential resistance R4, the filter capacitor C1 filtering that rectifier diode VD1 through connecting and rectifier diode VD1 negative pole connect obtains described detection voltage; Described detection voltage is connected to the base stage of the triode V1 of emitter grounding after resistance R 2 and resistance R 3 dividing potential drops, the collector electrode of described triode V1 is connected with the base stage of the triode V2 of emitter grounding through rectifier diode VD2, and the collector electrode of described triode V2 connects the I/O mouth of MCU; The guard signal of other protective circuits is connected to the base stage of described triode V2 after resistance R 6 and resistance R 7 dividing potential drops;
When field circuit works, rectification obtains voltage at filter capacitor C1 to vertical blanking impulse through rectifier diode VD1, and make triode V1 saturation conduction, make triode V1 collector electrode output low level, can't make diode VD2 conducting, other protective circuits are not exerted an influence, if other protective circuits are working properly, do not trigger and enter guard mode, triode V2 collector electrode output high level; When MCU recognizes signal on the I/O mouth and is high level, allow machine normally move;
When vertical output circuit work is undesired, vertical blanking impulse disappears, electric charge on the filter capacitor C1 exhausted through the very short time, so triode V1 can't conducting, triode V1 collector electrode output high level, make diode VD2 conducting work, and then make triode V2 saturation conduction, triode V2 collector electrode output low level; When MCU recognizes low level signal on the I/O mouth, external equipment is closed in immediately shut down procedure operation, makes machine enter holding state, and the user can't be by the button on the machine front panel or remote controller start, and namely machine enters the Protection state.
2. television airdrome guard method as claimed in claim 1 is characterized in that, other protective circuit that arranges in the described television set comprises: beam electronic current restriction ABL protective circuit, load short-circuit protection circuit, X ray protective circuit.
3. television airdrome protective circuit, it is characterized in that, vertical blanking impulse through capacitance C2 after straight, meet over the ground differential resistance R4 and fly-wheel diode VD3, fly-wheel diode VD3 plus earth, negative pole connects the common port of rectifier diode VD1 and capacitance C2, obtains differential signal voltage at differential resistance R4, the filter capacitor C1 filtering that rectifier diode VD1 through connecting and rectifier diode negative pole connect obtains to detect voltage; Described detection voltage is connected to the base stage of the triode V1 of emitter grounding after resistance R 2 and resistance R 3 dividing potential drops, the collector electrode of described triode V1 is connected with the base stage of the triode V2 of emitter grounding through rectifier diode VD2, and the collector electrode of described triode V2 connects the I/O mouth of MCU; The guard signal of other protective circuits is connected to the base stage of described triode V2 after resistance R 6 and resistance R 7 dividing potential drops;
When field circuit works, vertical blanking impulse obtains voltage through rectifies at filter capacitor C1, and make triode V1 saturation conduction, make triode V1 collector electrode output low level, can't make diode VD2 conducting, other protective circuits are not exerted an influence, if other protective circuits are working properly, do not trigger and enter guard mode, triode V2 collector electrode output high level; When MCU recognizes signal on the I/O mouth and is high level, allow machine normally move;
When vertical output circuit work is undesired, vertical blanking impulse disappears, electric charge on the filter capacitor C1 exhausted through the very short time, so triode V1 can't conducting, triode V1 collector electrode output high level, make diode VD2 conducting work, and then make triode V2 saturation conduction, triode V2 collector electrode output low level; When MCU recognizes low level signal on the I/O mouth, external equipment is closed in immediately shut down procedure operation, makes machine enter holding state, and the user can't be by the button on the machine front panel or remote controller start, and namely machine enters the Protection state.
4. television airdrome protective circuit as claimed in claim 3 is characterized in that, described vertical blanking impulse is obtained by the pumping source capacitance terminal of field IC.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008101832245A CN101442638B (en) | 2008-12-16 | 2008-12-16 | Protection method and circuit for television airdrome |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2008101832245A CN101442638B (en) | 2008-12-16 | 2008-12-16 | Protection method and circuit for television airdrome |
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| Publication Number | Publication Date |
|---|---|
| CN101442638A CN101442638A (en) | 2009-05-27 |
| CN101442638B true CN101442638B (en) | 2013-03-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2008101832245A Expired - Fee Related CN101442638B (en) | 2008-12-16 | 2008-12-16 | Protection method and circuit for television airdrome |
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Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110954848A (en) * | 2019-12-17 | 2020-04-03 | 杭州中恒电气股份有限公司 | Fuse wire detection line breakage detection circuit and method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2669527Y (en) * | 2003-12-29 | 2005-01-05 | 青岛海信电器股份有限公司 | Children-locking circuit for liquid crystal television receiver |
| CN2886949Y (en) * | 2006-01-25 | 2007-04-04 | 海信集团有限公司 | TV set interface circuit |
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2008
- 2008-12-16 CN CN2008101832245A patent/CN101442638B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2669527Y (en) * | 2003-12-29 | 2005-01-05 | 青岛海信电器股份有限公司 | Children-locking circuit for liquid crystal television receiver |
| CN2886949Y (en) * | 2006-01-25 | 2007-04-04 | 海信集团有限公司 | TV set interface circuit |
Non-Patent Citations (2)
| Title |
|---|
| JP特开2004-260276A 2004.09.16 |
| 王家淦，高敏荣.《大屏幕数字电视机行输出管的保护》.《电视技术》.1996,(第1期),37-40. * |
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| CN101442638A (en) | 2009-05-27 |
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Granted publication date: 20130327 Termination date: 20181216 |