CN200973134Y - Line failure protection circuit - Google Patents
Line failure protection circuit Download PDFInfo
- Publication number
- CN200973134Y CN200973134Y CN 200620160845 CN200620160845U CN200973134Y CN 200973134 Y CN200973134 Y CN 200973134Y CN 200620160845 CN200620160845 CN 200620160845 CN 200620160845 U CN200620160845 U CN 200620160845U CN 200973134 Y CN200973134 Y CN 200973134Y
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- power supply
- horizontal pulse
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Abstract
The utility model discloses a line invalidity protection circuit, which comprises a line pulse signal output terminal that outputs the line pulse signal when scanning out that the circuit is working normally; a voltage maintaining circuit that receives the pulse signal from the pulse signal output terminal output and then maintains the high electrical level DC voltage signal output in case of the line pulse signal; and a switch circuit, wherein the switch control terminal is connected to the output terminal of the voltage maintaining circuit, so as to control the power supply circuit to stop working when receiving the low electrical level control signal. The utility model adds the line pulse signal detection switch circuit between the TV set line scanning circuit and the power supply circuit so as to conduct a real-time detection to the line pulse signal in the line scanning circuit. When detection indicates abnormity in the line pulse signal, the switch control signal is output to the TV set power supply circuit so as to control the power supply circuit to stop working, so that the TV set circuit has an effective protection function, thereby avoiding burning of circuit apparatus.
Description
Technical field
The utility model belongs to technical field of television sets; relate to a kind of improvement of TV set circuit, specifically, relate to a kind of when the television set line-scan circuit lost efficacy; the control television power circuit quits work, with the protective circuit of guaranteeing that power supply and late-class circuit are avoided damaging.
Background technology
In existing TV set circuit, anomaly appears in line-scan circuit in the course of the work sometimes, and the horizontal pulse blackout causes television image normally to show.At this moment, because television power circuit and do not know that line-scan circuit lost efficacy, and therefore, can continue to power to line-scan circuit.In this case, be easy to cause burning of part of devices in the TV set circuit, cause system's operational reliability to reduce, television set complete machine quality is descended.
Summary of the invention
The utility model can cause dysgenic problem in order to solve to TV set circuit when line-scan circuit lost efficacy in the prior art; a kind of novel capable fail-safe circuit is provided; pass through simple circuit configuration; unusual time control power circuit takes place and quits work in the pulse signal of being expert at, to realize the effective protection to TV set circuit.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of capable fail-safe circuit comprises: horizontal pulse signal output part, output horizontal pulse signal when line-scan circuit is working properly; Voltage hold circuit receives the horizontal pulse signal from the output of horizontal pulse signal output part, and keeps output high-level DC voltage signal when the horizontal pulse signal is arranged; Switching circuit, its switch control end connects the output of described voltage hold circuit, and when receiving the low level control signal, the control power circuit quits work.
In order to realize the control of described switching circuit to power circuit, the gating end of described switching circuit is connected between the feeder ear and dc power supply of power supply control chip; When described holding circuit output low level signal, the blocking-up dc power supply is to the direct current supply of power supply control chip.Its particular circuit configurations is: the gating end one end ground connection of described switching circuit, the other end connects the feeder ear of described power supply control chip, is communicated with when described holding circuit output low level signal, drags down the feeder ear current potential of power supply control chip, it is quit work, and then block its output.
In order to simplify the switching circuit structure, to reduce cost, in described switching circuit, include two NPN type triodes, the base stage of the one NPN type triode is the switch control end of described switching circuit, the output that connects described voltage hold circuit, its grounded emitter, collector electrode connect the base stage of described the 2nd NPN type triode; The base stage of described the 2nd NPN type triode is in the signal output part of high level when connecting a start job simultaneously, grounded emitter, and collector electrode connects the feeder ear of power supply control chip in the described power circuit.The signal output part that is in high level during described start work is the standby signal output, one of them GPIO mouth of connected system CPU, and system CPU is by the effective standby signal of described GPIO mouth output low level.When television boot-strap was worked, system CPU was by its described GPIO mouth output high level signal, only when receiving standby command, and output low level Opportunity awaiting control for linear signal.
In described voltage hold circuit, include a voltage charging and discharging circuit, when described horizontal pulse signal output part has the output of horizontal pulse signal, charge, and output high-level DC voltage signal; When the horizontal pulse blackout of described horizontal pulse signal output part, discharge, and then the output low level signal.Its particular circuit configurations is: in described voltage hold circuit, the horizontal pulse signal output part connects the negative electrode of a voltage-stabiliser tube on the other hand on the one hand by a storage capacitor ground connection, and through bleeder resistance ground connection; The anode of described voltage-stabiliser tube connects the switch control end of described switching circuit by the capacitance-resistance filter network.
In order to prevent that storage capacitor discharges to line-scan circuit when line-scan circuit lost efficacy, between described horizontal pulse signal output part and voltage hold circuit, be connected with a switching diode; The anode of described switching diode connects the horizontal pulse signal output part, and negative electrode connects the input of described voltage hold circuit, and after the pulse signal that guarantees to be expert at disappeared, the electric charge in the storage capacitor only discharged over the ground by described bleeder resistance.
Compared with prior art; advantage of the present utility model and good effect are: the utility model is by setting up horizontal pulse input switching circuit between television set line-scan circuit and power circuit; horizontal pulse signal in the line-scan circuit is detected in real time; occur when unusual when detecting the horizontal pulse signal; to the television power circuit output switch control signal; the control power circuit quits work, thereby TV set circuit is played effective protective effect, has avoided burning of circuit elements device.Capable fail-safe circuit of the present utility model is simple in structure, design cost is cheap, easy realization, has effectively improved reliability of system operation, has guaranteed the complete machine quality of television set.
Description of drawings
Fig. 1 is the schematic diagram of row fail-safe circuit in the utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done explanation in further detail.
For TV set circuit, the protection of power circuit is very important, and it is a key of guaranteeing the normal operation of circuit system.The factor that causes the power circuit operation irregularity has a variety of, and the utility model has promptly proposed a kind ofly to occur when unusual at line-scan circuit, the control circuit that TV set power and late-class circuit thereof are effectively protected, and be referred to as the row fail-safe circuit.
The capable fail-safe circuit that the utility model proposed comprise the horizontal pulse signal output part and with its voltage hold circuit that is connected successively and switching circuit.Wherein, described horizontal pulse signal output part is exported the horizontal pulse signal when line-scan circuit is working properly, and described horizontal pulse signal is outputed in the connected voltage protection circuit; After described voltage protection circuit is handled the horizontal pulse signal that receives, when being arranged, the horizontal pulse signal keeps output high-level DC voltage signal; The switch control end of described switching circuit connects the output of described voltage hold circuit, and when receiving the low level control signal, the control power circuit quits work.
In order to realize the control of described switching circuit to power circuit, the gating end of switching circuit is connected between the feeder ear and dc power supply of power supply control chip; At described holding circuit output low level signal, pulse signal disappears at once, and line-scan circuit occurs when unusual, and the blocking-up dc power supply is to the direct current supply of power supply control chip.Its particular circuit configurations is: the gating end one end ground connection of described switching circuit; the other end connects the feeder ear of described power supply control chip; when described holding circuit output low level signal, be communicated with; drag down the feeder ear current potential of power supply control chip; the power supply control chip outage is quit work; block its pwm control signal output, and then follow-up switching power circuit is quit work, realize effective protection power supply and late-class circuit thereof.
In order to simplify circuit structure, to reduce cost, the utility model proposes capable fail-safe circuit structure as shown in Figure 1.Among Fig. 1, in described voltage hold circuit, include a voltage charging and discharging circuit, when described horizontal pulse signal output part has the output of horizontal pulse signal, charge, and output high-level DC voltage signal; When the horizontal pulse blackout of described horizontal pulse signal output part, discharge, and then the output low level signal.Its particular circuit configurations is: the horizontal pulse signal output part connects the negative electrode of a voltage-stabiliser tube DZ481 on the other hand on the one hand by a storage capacitor C499 ground connection through resistance R 482, and through bleeder resistance R483 ground connection; The anode of described voltage-stabiliser tube DZ481 connects the switch control end of described switching circuit by the capacitance-resistance filter network of being made of resistance R 481, R487 and capacitor C 487.
In order to prevent that when line-scan circuit lost efficacy, storage capacitor C499 discharged to line-scan circuit, between described horizontal pulse signal output part and voltage hold circuit, be connected with a switching diode VD480.The anode of described switching diode VD480 connects the horizontal pulse signal output part, and negative electrode connects the input of described voltage hold circuit, and after the pulse signal that guarantees to be expert at disappeared, the electric charge among the storage capacitor C49 only discharged over the ground by described bleeder resistance R483.
In described switching circuit, include two NPN type triode V487, V804, wherein, the base stage of NPN type triode V487 is the switch control end of described switching circuit, the output that connects described voltage hold circuit, its grounded emitter, collector electrode connect the base stage of described NPN type triode V804.The base stage of described NPN type triode V804 is in the signal output part of high level when connecting a start job simultaneously, grounded emitter, and collector electrode connects the feeder ear of power supply control chip in the described power circuit.The signal output part that is in high level during described start work is standby signal output Standby, one of them GPIO mouth of connected system CPU, and system CPU is by the effective standby signal of described GPIO mouth output low level.When television boot-strap was worked, system CPU was by its GPIO mouth output high level signal, i.e. Standby end output high level signal.When the user sent standby command by remote controller or standby button, CPU was by its GPIO mouth output low level Opportunity awaiting control for linear signal, and promptly the current potential of Standby end is a low level.
In order to mate the base voltage value of NPN type triode V487, the base stage of described NPN type triode V487 connects the collector electrode of a positive-negative-positive triode V488, the base stage of described positive-negative-positive triode V488 connects the collector electrode of NPN type triode V487 on the one hand, connects the base stage of NPN type triode V804 on the other hand by resistance R 489, R819; The emitter of described positive-negative-positive triode V488 also connects the base stage of described NPN type triode V804 by capacitor C 489, resistance R 819.Stablize for the base voltage that makes described NPN type triode V804, on the base stage of described NPN type triode V804, be connected with capacitance-resistance filter network R820 in parallel, the C826 of ground connection.
The operation principle of described capable fail-safe circuit is: when the TV set circuit operate as normal; the horizontal pulse signal charges to storage capacitor C499 by switching diode VD480; and the high-level DC voltage signal is exported in maintenance when the horizontal pulse signal is arranged; and then reverse breakdown voltage stabilizing didoe DZ481; make the voltage that outputs to triode V487 base stage be in high level state; triode V487 conducting; drag down its collector potential; and then the base potential that makes triode V804 is a low level; triode V804 ends, and does not influence the operate as normal of power circuit.At this moment, DC power supply makes the power supply control chip operate as normal for power supply control chip provides stable operating voltage, and output PWM pulse-width signal is elementary to switch transformer, control its switching frequency, and then each road voltage of switch transformer secondary output output is effectively reconciled.
When the work of line-scan circuit occurs when unusual; as the horizontal pulse blackout; switching diode VD480 oppositely ends; storage capacitor C499 is by resistance R 482; R483 is discharge rapidly over the ground; the cathode potential of voltage stabilizing didoe DZ481 is dragged down; voltage-stabiliser tube DZ481 does not play pressure stabilization function; triode V487 is owing to its base potential is that low level is ended; affact the base stage of described NPN type triode V804 from the high level signal of Standby end output; control its conducting; and then drag down the feeder ear current potential of power supply control chip; the power supply control chip outage is quit work; block its pwm control signal output, make follow-up switching power circuit quit work, realized protective effect power circuit and late-class circuit thereof.
The utility model had been realized when line-scan circuit lost efficacy burning of circuit elements device avoided in effective protection of TV set circuit by adopting above-mentioned simple circuit configuration, had improved the reliability of whole set of television.Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (10)
1. a capable fail-safe circuit is characterized in that: comprise
The horizontal pulse signal output part, output horizontal pulse signal when line-scan circuit is working properly;
Voltage hold circuit receives the horizontal pulse signal from the output of horizontal pulse signal output part, and keeps output high-level DC voltage signal when the horizontal pulse signal is arranged;
Switching circuit, its switch control end connects the output of described voltage hold circuit, and when receiving the low level control signal, the control power circuit quits work.
2. capable fail-safe circuit according to claim 1 is characterized in that: the gating end of described switching circuit is connected between the feeder ear and dc power supply of power supply control chip; When described holding circuit output low level signal, the blocking-up dc power supply is to the direct current supply of power supply control chip.
3. capable fail-safe circuit according to claim 2; it is characterized in that: the gating end one end ground connection of described switching circuit; the other end connects the feeder ear of described power supply control chip; when described holding circuit output low level signal, be communicated with; drag down the feeder ear current potential of power supply control chip; it is quit work, and then block its output.
4. capable fail-safe circuit according to claim 1 and 2, it is characterized in that: in described switching circuit, include two NPN type triodes, the base stage of the one NPN type triode is the switch control end of described switching circuit, the output that connects described voltage hold circuit, its grounded emitter, collector electrode connect the base stage of described the 2nd NPN type triode; The base stage of described the 2nd NPN type triode is in the signal output part of high level when connecting a start job simultaneously, grounded emitter, and collector electrode connects the feeder ear of power supply control chip in the described power circuit.
5. capable fail-safe circuit according to claim 4 is characterized in that: the signal output part that is in high level during described start work is the standby signal output.
6. capable fail-safe circuit according to claim 5 is characterized in that: one of them GPIO mouth of described standby signal output connected system CPU, system CPU is by the effective standby signal of described GPIO mouth output low level.
7. capable fail-safe circuit according to claim 1, it is characterized in that: in described voltage hold circuit, include a voltage charging and discharging circuit, when having the output of horizontal pulse signal, described horizontal pulse signal output part charges, and output high-level DC voltage signal; When the horizontal pulse blackout of described horizontal pulse signal output part, discharge, and then the output low level signal.
8. capable fail-safe circuit according to claim 7 is characterized in that: in described voltage hold circuit, the horizontal pulse signal output part connects the negative electrode of a voltage-stabiliser tube on the other hand on the one hand by a storage capacitor ground connection, and through bleeder resistance ground connection; The anode of described voltage-stabiliser tube connects the switch control end of described switching circuit.
9. capable fail-safe circuit according to claim 7 is characterized in that: described horizontal pulse signal output part connects the anode of a switching diode, and the negative electrode of described switching diode connects the input of described voltage hold circuit.
10. capable fail-safe circuit according to claim 8 is characterized in that: be connected with the capacitance-resistance filter network between the switch control end of the anode of described voltage-stabiliser tube and switching circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620160845 CN200973134Y (en) | 2006-11-21 | 2006-11-21 | Line failure protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620160845 CN200973134Y (en) | 2006-11-21 | 2006-11-21 | Line failure protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN200973134Y true CN200973134Y (en) | 2007-11-07 |
Family
ID=38884383
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620160845 Expired - Fee Related CN200973134Y (en) | 2006-11-21 | 2006-11-21 | Line failure protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN200973134Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101465948B (en) * | 2007-12-19 | 2011-01-12 | 深圳Tcl新技术有限公司 | Safety protection device for multifunctional television circuit |
| CN104469352A (en) * | 2014-12-12 | 2015-03-25 | 龙迅半导体科技(合肥)有限公司 | Input signal state detecting circuit, signal converting system and playing device |
| CN112995769A (en) * | 2019-12-13 | 2021-06-18 | 中盈优创资讯科技有限公司 | Shutdown management method and system for high-definition television |
-
2006
- 2006-11-21 CN CN 200620160845 patent/CN200973134Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101465948B (en) * | 2007-12-19 | 2011-01-12 | 深圳Tcl新技术有限公司 | Safety protection device for multifunctional television circuit |
| CN104469352A (en) * | 2014-12-12 | 2015-03-25 | 龙迅半导体科技(合肥)有限公司 | Input signal state detecting circuit, signal converting system and playing device |
| CN104469352B (en) * | 2014-12-12 | 2017-08-11 | 龙迅半导体（合肥）股份有限公司 | A kind of status input signal detection circuit, signal translating system and playback equipment |
| CN112995769A (en) * | 2019-12-13 | 2021-06-18 | 中盈优创资讯科技有限公司 | Shutdown management method and system for high-definition television |
| CN112995769B (en) * | 2019-12-13 | 2022-10-04 | 中盈优创资讯科技有限公司 | Shutdown management method and system for high-definition television |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20071107 Termination date: 20101121 |