CN201393275Y - Voltage conversion circuit of liquid crystal television - Google Patents
Voltage conversion circuit of liquid crystal television Download PDFInfo
- Publication number
- CN201393275Y CN201393275Y CN200920130330U CN200920130330U CN201393275Y CN 201393275 Y CN201393275 Y CN 201393275Y CN 200920130330 U CN200920130330 U CN 200920130330U CN 200920130330 U CN200920130330 U CN 200920130330U CN 201393275 Y CN201393275 Y CN 201393275Y
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Abstract
The utility model discloses a voltage conversion circuit of liquid crystal television, which comprises a voltage impulse circuit, a boosted circuit and a decompression which are connected with the voltage impulse circuit for receiving voltage impulse output by the voltage impulse circuit, and a feedback circuit which is connected between the output of the decompression circuit and the voltage impulse circuit. The voltage conversion circuit of liquid crystal television can supply stable +5V voltage and +33V voltage, and has simple and reliable circuit, excellent stability and low cost.
Description
[technical field]
The utility model relates to technical field of television sets, particularly a kind of voltage conversion circuit of LCD TV.
[background technology]
The liquid crystal TV set mainboard generally needs one+5V voltage, and this voltage is generally provided by the liquid crystal TV set power supply, yet this makes the power supply of liquid crystal TV set become very complicated, has increased the connecting line between power supply and the mainboard simultaneously, and packaging technology is also complicated.Along with market competition is more and more fierce, television set production firm extensively adopts the separate type high-frequency tuner in order to reduce cost, and this tuner needs the tuning voltage of an about+33V.So the liquid crystal TV set mainboard needs to increase the voltage of one+33V again again except that+5V voltage.At present, this tuning voltage generally is to realize multiplication of voltage or use special conversion chip to realize by discrete component.Yet, use discrete component to realize that multiplication of voltage can cause the components and parts that use more, the circuit structure complexity, the parameter configuration of components and parts difficulty relatively in the circuit is subjected to condition effect such as temperature bigger, and stability is low; Realize then more complicated by the conversion chip of special use, cost is very high.Provide liquid crystal TV set a kind of good stability so be necessary research, and the low voltage conversion circuit of cost, can change simultaneously to+5V voltage and+33V voltage.
[utility model content]
For addressing the above problem, main purpose of the present utility model is to provide a kind of good stability, and the voltage conversion circuit of the low LCD TV of cost.
For achieving the above object, the technical solution of the utility model is:
A kind of voltage conversion circuit of LCD TV, comprise voltage pulse circuit, be connected the booster circuit and the reduction voltage circuit of the potential pulse of exporting with the reception voltage pulse circuit with voltage pulse circuit and be connected in the output of reduction voltage circuit and the feedback circuit between the voltage pulse circuit.
Further, described voltage pulse circuit connection+12V voltage input.
Further, described booster circuit also is connected with+input of 12V voltage.
Further, described booster circuit be used for the input+12V voltage transitions one-tenth+33V tuning voltage, output+33V voltage; And described reduction voltage circuit is used for converting+5V voltage the potential pulse of voltage pulse circuit output to output+5V voltage.
Further, described feedback circuit is used for feeding back to voltage pulse circuit with behind+5V the voltage sampling, and is stable to export+5V voltage.
Compared to prior art, the voltage conversion circuit of the utility model LCD TV can provide, and stable+5V voltage reaches+33V voltage, and circuit is simple and reliable, good stability, and cost is low.
[description of drawings]
Fig. 1 is a theory diagram of the present utility model;
Fig. 2 is circuit theory diagrams of the present utility model.
[embodiment]
See also shown in Figure 1, the voltage conversion circuit of a kind of LCD TV of the utility model comprises the voltage pulse circuit of connection+12V voltage input, is connected the booster circuit and the reduction voltage circuit of the potential pulse of exporting with the reception voltage pulse circuit with voltage pulse circuit and is connected in the output of reduction voltage circuit and the feedback circuit between the voltage pulse circuit.Wherein, described booster circuit also is connected with+input of 12V voltage; Described booster circuit be used for the input+12V voltage transitions one-tenth+33V tuning voltage, output+33V voltage; Described reduction voltage circuit is used for converting+5V voltage the potential pulse of voltage pulse circuit output to output+5V voltage; And described feedback circuit is used for feeding back to voltage pulse circuit with behind+5V the voltage sampling, and is stable to export+5V voltage.
+ 12V voltage is the voltage of liquid crystal TV set power supply output, and this voltage inputs to voltage pulse circuit and booster circuit.Voltage pulse circuit general+12V voltage transitions becomes potential pulse output, and this potential pulse exports booster circuit and reduction voltage circuit to; Voltage pulse circuit is regulated output current according to the voltage of feedback circuit feedback, with stable+5V voltage output.Booster circuit is under the control of above-mentioned potential pulse, and general+12V voltage transitions one-tenth+33V voltage is exported, and this voltage is tuning voltage.And reduction voltage circuit directly converts the potential pulse of described input to+5V output, and input to feedback circuit.Feedback circuit is right+feed back to voltage pulse circuit behind the 5V voltage sampling, with the electric current of regulation voltage impulse circuit output, make the stable+5V voltage of reduction voltage circuit output.
See also shown in Figure 2ly, voltage pulse circuit includes power management IC U22, first resistance R 271, second resistance R 275 and first capacitor C 344, second capacitor C 345.Wherein ,+12V voltage connects power management ICU22 through first resistance R 271.Second resistance R 275 is connected back with second capacitor C 345 and first capacitor C 344 is formed a circuit in parallel, and this parallel circuits one end connects power management IC U22, other end ground connection.Power management IC adopts APW7080, and it adopts current control mode, has very wide voltage input and voltage output.Input+12V voltage is through after the voltage pulse circuit conversion, output high level amplitude is 380KHZ and the potential pulse ULX with particular duty cycle for+12V, frequency, this potential pulse ULX is divided into two-way, one tunnel switch control impuls as booster circuit, another road is as the input pulse of reduction voltage circuit.
Booster circuit includes triode Q49, the first diode D54 that is connected with triode Q49 and voltage-stabiliser tube D33 and earth resistance R72 and ground capacity C270.Described triode Q49 is the NPN triode, and potential pulse ULX is connected to the base stage of triode Q49 through the 3rd resistance R 245.The collector electrode of triode Q49 connects the positive pole of the first diode D54.And+12V voltage also is connected to the positive pole of the first diode D54 by a low inductance L 21.First inductance L 21 is energy storage inductors of booster circuit, and voltage-stabiliser tube D33 employing voltage stabilized range is the voltage-stabiliser tube of 31V to 35V, and the tuning voltage scope of this voltage stabilized range and high-frequency tuner is identical; Ground capacity C270 is a storage capacitor; The 3rd resistance R 245 and triode Q49 form control switch, for guaranteeing the quick and complete conducting of triode Q49 energy, the 3rd resistance R 245 value 6.8K or littler.At pulse ULX is between low period, and the base stage level of triode Q49 is lower than 0V, and triode Q49 ends; The electric current of energy storage inductor L21 is by the first diode D54, the first diode D54 conducting, A point voltage size is the pressure drop sum of the tuning voltage and the first diode D54, the A point voltage is greater than+12V, electric current in the inductance L 21 reduces, energy storage inductor L21 provides energy to load and ground capacity C270, the C270 energy storage of charging.At pulse ULX is between high period, and the base stage of triode Q49 is a high level, triode Q49 saturation conduction, the A point voltage is approximately 0.3V, is lower than+33V, and the electric current in first inductance L 21 increases, the second diode D54 does not have conducting, and ground capacity C270 discharge provides energy to load.What potential pulse ULX control triode Q49 did not stop alternately ends and saturation conduction, win inductance L 21, ground capacity C270 are ceaselessly released energy and stored energy, + 12V voltage transitions is become approximately+voltage of 33V, by voltage-stabiliser tube D33 make output+33V is subjected to load effect little, exports stable+33V voltage.
Reduction voltage circuit includes the second diode D34, second inductance L 22, and electric capacity of voltage regulation C268, go lotus root capacitor C 342.Wherein, the second diode D34 is a fly-wheel diode, and second inductance L 22 is an energy storage inductor.Each components and parts in the reduction voltage circuit are got appropriate value, are between high period at pulse ULX, and ULX is+12V that the B point is+5V; Second inductance L, 22 electric currents increase, stored energy; The second diode D34 ends, and does not have electric current to pass through.Pulse ULX is between low period, because the pressure stabilization function of electric capacity of voltage regulation C268, the B point remains+5V, and second inductance L, 22 electric currents reduce, and release energy; Second inductance L 22 is by the second diode D34 afterflow, the second diode D34 conducting.The potential pulse ULX of input makes charging and the discharge that second inductance L 22 is not stopped, and general+12V point pressure is converted to+5V voltage.
Feedback circuit includes the 4th resistance R 274 and the 5th resistance R 276, wherein, and the 5th resistance R 276 1 end ground connection.Feed back to power management IC U22 behind the feedback circuit general+5V voltage sampling, by power management IC U22 internal regulation,, stable+the 5V output voltage to regulate output current.
Most preferred embodiment described above only is that the utility model is set forth and illustrated, but is not limited to disclosed any concrete form, and it is possible carrying out many modifications and variations.
Claims (8)
1. the voltage conversion circuit of a LCD TV, comprise voltage pulse circuit, it is characterized in that: be connected the booster circuit and the reduction voltage circuit of the potential pulse of exporting with the reception voltage pulse circuit with voltage pulse circuit and be connected in the output of reduction voltage circuit and the feedback circuit between the voltage pulse circuit.
2. the voltage conversion circuit of LCD TV as claimed in claim 1 is characterized in that: described voltage pulse circuit connection+12V voltage input.
3. the voltage conversion circuit of LCD TV as claimed in claim 2 is characterized in that: described booster circuit also is connected with+input of 12V voltage.
4. the voltage conversion circuit of LCD TV as claimed in claim 3 is characterized in that: described booster circuit be used for input+12V voltage transitions one-tenth+33V tuning voltage, output+33V voltage; And described reduction voltage circuit is used for converting+5V voltage the potential pulse of voltage pulse circuit output to output+5V voltage.
5. the voltage conversion circuit of LCD TV as claimed in claim 4 is characterized in that: described feedback circuit is used for feeding back to voltage pulse circuit with behind+5V the voltage sampling, and is stable to export+5V voltage.
6. the voltage conversion circuit of LCD TV as claimed in claim 5, it is characterized in that: described voltage pulse circuit includes power management IC (U22), first resistance (R271), second resistance (R275) and first electric capacity (C344), second electric capacity (C345); Wherein, + 12V voltage connects power management IC (U22) through first resistance (R271), second resistance (R275) is connected back with second electric capacity (C345) and first electric capacity (C344) is formed a circuit in parallel, and this parallel circuits one end connects power management IC (U22), other end ground connection.
7. the voltage conversion circuit of LCD TV as claimed in claim 6 is characterized in that: described booster circuit includes triode (Q49), first diode (D54) that is connected with triode (Q49) and voltage-stabiliser tube (D33) and earth resistance (R72) and ground capacity (C270); Described triode (Q49) is the NPN triode, potential pulse ULX is connected to the base stage of triode (Q49) through the 3rd resistance (R245), the collector electrode of triode (Q49) connects the positive pole of first diode (D54), and+12V voltage also is connected to the positive pole of first diode (D54) by a low inductance (L21).
8. the voltage conversion circuit of LCD TV as claimed in claim 7 is characterized in that: described feedback circuit includes the 4th resistance (R274) and the 5th resistance (R276), wherein, and the 5th resistance (R276) end ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920130330U CN201393275Y (en) | 2009-04-03 | 2009-04-03 | Voltage conversion circuit of liquid crystal television |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920130330U CN201393275Y (en) | 2009-04-03 | 2009-04-03 | Voltage conversion circuit of liquid crystal television |
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| Publication Number | Publication Date |
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| CN201393275Y true CN201393275Y (en) | 2010-01-27 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN200920130330U Expired - Fee Related CN201393275Y (en) | 2009-04-03 | 2009-04-03 | Voltage conversion circuit of liquid crystal television |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101909184A (en) * | 2010-07-07 | 2010-12-08 | 深圳创维－Rgb电子有限公司 | Tuning voltage generation circuit of tuner |
| CN103078495A (en) * | 2013-01-29 | 2013-05-01 | 矽力杰半导体技术(杭州)有限公司 | High-efficient buck-boost converter and control method thereof |
| CN106033880A (en) * | 2015-03-09 | 2016-10-19 | 何曙光 | Hiccup type protection circuits for DC power supply |
| CN107367854A (en) * | 2017-01-06 | 2017-11-21 | 京东方科技集团股份有限公司 | Drive circuit, driving method and the electronics curtain of liquid crystal panel |
-
2009
- 2009-04-03 CN CN200920130330U patent/CN201393275Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101909184A (en) * | 2010-07-07 | 2010-12-08 | 深圳创维－Rgb电子有限公司 | Tuning voltage generation circuit of tuner |
| CN101909184B (en) * | 2010-07-07 | 2013-04-17 | 深圳创维－Rgb电子有限公司 | Tuning voltage generation circuit of tuner |
| CN103078495A (en) * | 2013-01-29 | 2013-05-01 | 矽力杰半导体技术(杭州)有限公司 | High-efficient buck-boost converter and control method thereof |
| CN103078495B (en) * | 2013-01-29 | 2016-06-01 | 矽力杰半导体技术(杭州)有限公司 | A kind of high efficiency type of voltage step-up/down converter and control method thereof |
| CN106033880A (en) * | 2015-03-09 | 2016-10-19 | 何曙光 | Hiccup type protection circuits for DC power supply |
| CN106033880B (en) * | 2015-03-09 | 2019-01-22 | 广东泓睿科技有限公司 | DC power supply hiccup formula protects circuit |
| CN107367854A (en) * | 2017-01-06 | 2017-11-21 | 京东方科技集团股份有限公司 | Drive circuit, driving method and the electronics curtain of liquid crystal panel |
| CN107367854B (en) * | 2017-01-06 | 2020-05-05 | 京东方科技集团股份有限公司 | Drive circuit and drive method of liquid crystal panel and electronic curtain |
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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: 20100127 Termination date: 20140403 |