CN2836374Y - 2-in-1 power supply circuit for liquid crystal TV set - Google Patents
2-in-1 power supply circuit for liquid crystal TV set Download PDFInfo
- Publication number
- CN2836374Y CN2836374Y CN 200520125565 CN200520125565U CN2836374Y CN 2836374 Y CN2836374 Y CN 2836374Y CN 200520125565 CN200520125565 CN 200520125565 CN 200520125565 U CN200520125565 U CN 200520125565U CN 2836374 Y CN2836374 Y CN 2836374Y
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- power supply
- inverter
- connects
- transformer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The utility model discloses a 2-in-1 power supply circuit for a liquid crystal TV. A power supply of a host and a power supply of back light are arranged on the same circuit plate. +12V direct current generated by a voltage reduction transformer in the power supply of the host is supplied for a circuit of the power supply of back light. Low voltage direct current which is inputted is converted into 1000V high voltage by a voltage boosting transformer in the circuit of the power supply of back light, which provides a working power supply for a light tube of back light. A pole changing device INVERTER is arranged in the power supply of back light to receive a switching signal and a light adjusting signal which are emitted by a CPU in a master control plate for the power supply of back light. A PWM signal is outputted by the output end of the pole changing device INVERTER, the duty ratio of the PWM signal can be adjusted, and the on-off of the light tube of back light and the adjustment for brightness are controlled. When the liquid crystal TV of the utility model is used, a user only needs to insert a power plug, the normal work of the complete TV can be realized, the user's usage is convenient, and the performance of the complete TV of the liquid crystal TV is improved.
Description
Technical field
The utility model relates to a kind of improvement of TV set circuit, specifically, relates to a kind of treatment circuit that the power supply of liquid crystal TV set is integrated.
Background technology
At present, all be provided with two cover electric power systems for common liquid crystal TV set, one cover electric power system is converted to low-voltage DC with the alternating current 220V civil power provides working power for television main, another set of electric power system is converted to the alternating current 220V civil power in the backlight electric power plate that direct current 12V outputs to liquid crystal display screen by adapter, boost to 1000V by transformer, and then the high voltage supply that provides backlight of liquid crystal display screen is provided.Be arranged because the host power supply of liquid crystal TV set and the power supply of backlight electric power plate all divide, two plugs so the user need peg graft when watching LCD TV use extremely inconvenient.And host power supply and backlight electric power branch be arranged and also need to increase external line, the complete machine cost raise, but also can cause the introducing of external interference signal, thereby reduced the complete machine performance of liquid crystal TV set.
Summary of the invention
The utility model raises in order to solve in the prior art host power supply and the backlight electric power branch cost that is caused that is arranged, easily introduce the problem of external interference, a kind of novel liquid crystal TV set power circuit is provided, by host power supply and backlight electric power are designed on the circuit board, thereby effectively reduce the complete machine cost, reduced external disturbance, the user only need insert an attaching plug when using television set, can realize the operate as normal of complete machine, thereby greatly convenient for users to use, improved the complete machine performance of liquid crystal TV set.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of two-in-one power circuit of liquid crystal TV set comprises host power supply and backlight electric power, and described host power supply and backlight electric power are arranged on the same circuit board.
As further qualification to technique scheme, in described host power supply, the 220V alternating current is converted to the end that direct current is connected the elementary winding of step-down transformer on the one hand after rectification and filter circuit are handled, link to each other through the voltage input end of resistance with a pwm chip on the other hand; The pwm signal output of described pwm chip links to each other through the other end of a switch element with the elementary winding of described step-down transformer; The secondary winding of described step-down transformer is converted to primary voltage+12V and+the low-voltage DC output of 5V.Described switch element adopts a N-channel MOS pipe to realize that the grid of described metal-oxide-semiconductor connects the pwm signal output of described pwm chip, source ground, and drain electrode connects the elementary winding of described step-down transformer.
As further limiting again to technique scheme, in described backlight electric power, by the output of the secondary winding of step-down transformer+the 12V direct voltage connects the elementary winding of step-up transformer through switch chip, and then connects the backlight lamp tube socket of liquid crystal TV set by the secondary winding of step-up transformer.In described liquid crystal TV set, be provided with two backlight lamp tubes, described switch chip and step-up transformer all include two, + 12V direct voltage connects the voltage input end of two switch chips respectively, one of the output of two switch chips links to each other with the end of the same name of two elementary windings of step-up transformer, and another links to each other with the different name end of described two elementary windings of step-up transformer; The secondary winding of described two step-up transformers is connected one to one with the socket of two backlight lamp tubes.
As further limiting again to technique scheme, the switch controlling signal of described backlight electric power is by the GPIO mouth output of CPU on the master control borad, the GPIO mouth of described CPU connects the control end of a switching circuit, gating passage one end of described switching circuit connects described step-down transformer output+5V DC power supply, the other end connects the power end of an inverter INVERTER, and the pwm signal output of described inverter INVERTER connects the output control terminal of described switch chip.Described switching circuit is connected realization by a NPN type triode with a positive-negative-positive triode; Wherein, the base stage of NPN type triode connects the GPIO mouth of described CPU, grounded emitter, and collector electrode connects the base stage of described positive-negative-positive triode, emitter connection+5V the direct voltage of described positive-negative-positive triode, collector electrode connects the power end of described inverter INVERTER.The signal input end of described inverter INVERTER receives the brightness regulated signal that CPU sends, and changes the pwm signal duty ratio of described inverter INVERTER output according to the magnitude of voltage of input signal.
As further qualification to technique scheme, described switch chip adopts N+P combination metal-oxide-semiconductor switch chip to realize, the model of inverter INVERTER is BIT3105, the source S 1 of two metal-oxide-semiconductor switch chips is connection+12V direct voltage all, grid G 1 links to each other with POUT2, the POUT1 end of inverter BIT3105 respectively, grid G 2 links to each other with NOUT2, the NOUT1 end of inverter BIT3105 respectively, and drain D 1, D2 connect the elementary winding of described step-up transformer.The model of described pwm chip is SG6841S.
Compared with prior art, advantage of the present utility model and good effect are: the utility model is by being arranged on host power supply and backlight electric power on the same circuit board, utilize that step-down transformer in the host power supply generates+the 12V direct current is the backlight electric power circuit supply, by the step-up transformer in the backlight electric power circuit low-voltage DC of importing is converted to the 1000V high pressure, for backlight lamp tube provides working power.In described backlight electric power, be provided with inverter INVERTER, backlight electric power switching signal and dim signal that CPU in the master control borad is sent receive, and then by the adjustable pwm signal of its output output duty cycle, the switch of control backlight lamp tube and the adjusting of brightness.Liquid crystal TV set of the present utility model is by being arranged on host power supply and backlight electric power on the same circuit board, the user only need insert an attaching plug when using television set, can realize the operate as normal of complete machine, thereby greatly convenient for users to use, improved the complete machine performance of liquid crystal TV set.
Description of drawings
Fig. 1 is the circuit theory diagrams of host power supply in the utility model;
Fig. 2 is the circuit theory diagrams of backlight electric power in the utility model;
Fig. 3 is the signal flow block diagram of power circuit in the utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done explanation in further detail.
Power circuit of the present utility model designs host power supply and backlight electric power on a circuit board, and wherein the circuit theory diagrams of host power supply are referring to shown in Figure 1.Among Fig. 1, the alternating current 220V civil power inserts host power supply by socket CN1F, connect bridge rectifier BD1F through fuse F1F, inductance L F1F, LF2F, alternating current is become direct current after capacitor C 3F filtering, one the tunnel outputs to the voltage input end VIN that model is the pwm chip U1F of SG6841S after divider resistance R5F～R8F step-down, another road connects 1 end of the elementary winding of step-down transformer T1F.The door end Gate of described pwm chip U1F is connected the grid of switch MOS pipe Q1F through resistance R 9F and diode D1F, output PWM pulse-width signal is controlled the conducting of metal-oxide-semiconductor Q1F and is ended, the source electrode of described metal-oxide-semiconductor Q1F is through parallel resistance R12F, R29F～R32F ground connection, drain electrode connects 5 ends of the elementary winding of described step-down transformer T1F, and then realizes the switch control to transformer T1F.Described transformer T1F is converted to secondary low-voltage with elementary high pressure, by two secondary winding respectively through diode D3F, D4F, inductance L 1F, L2F output+12V and+the 5V DC power supply.Described+12V DC power supply is respectively backlight electric power circuit and sound power amplifier and tuner working power is provided, and+5V DC power supply provides direct current supply for signal processing chip, liquid crystal display screen signal processing module, and the concrete signal flow process is referring to shown in Figure 3.
Among Fig. 2, by host power supply circuit output+the 12V DC power supply is after capacitor C 6, C7 filtering, the source S 1 that connects switch chip U2, U3, described switch chip adopts N+P combination metal-oxide-semiconductor switch chip to realize that the grid G 1 of switch chip U2, U3, G2 connect positive and negative pwm signal output POUT2, POUT1 and NOUT2, the NOUT1 of inverter U1 respectively.It is the integrated chip realization of BIT3105 that described inverter U1 adopts model, and its power supply side AVDD exports+the 5V DC power supply via the switching circuit connection host power supply circuit that transistor Q1, Q2 form.Wherein, the GPIO mouth of the base stage of NPN type triode Q2 CPU on resistance R 25 connection master control borads receives the backlight electric power switching signal ON/OFF that CPU exports, grounded emitter, and collector electrode connects the base stage of positive-negative-positive triode Q1; Emitter connection+5V the DC power supply of described positive-negative-positive triode Q1, collector electrode connects the power supply side AVDD of inverter U1.When CPU sends high level starting-up signal ON, triode Q1, Q2 conducting ,+5V DC power supply outputs to the power supply side AVDD of inverter U1, and U1 provides working power for inverter.At this moment, 0～5V dim signal the ADJ that sends by CPU is connected to the signal input end of inverter U1 through resistance R 1, R3, inverter U1 is according to the dim signal size of input, export pwm signal by its output POUT2, POUT1 and NOUT2, NOUT1 with duty ratio corresponding, and then conducting and the cut-off state of control switch chip U2, U3, realize switch control to transformer T1, T2.Described transformer T1, T2 are converted to the 1000V high pressure with the low-voltage DC of input, drive two backlight lamp tube startup work.When CPU sent low level off signal OFF, triode Q1, Q2 all ended, and the power supply side AVDD dead electricity of inverter U1 quits work, and the entire backlight power circuit is in off position, and backlight lamp tube extinguishes.
The utility model is incorporated into host power supply and backlight electric power on the circuit board by adopting above-mentioned simple circuit configuration, thereby reduced power volume, reduced stand-by power consumption, effectively avoided the introducing of external interference, convenient for users to use, provide more reliable assurance to the complete machine quality.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. the two-in-one power circuit of a liquid crystal TV set comprises host power supply and backlight electric power, it is characterized in that: described host power supply and backlight electric power are arranged on the same circuit board.
2. the two-in-one power circuit of liquid crystal TV set according to claim 1, it is characterized in that: in described host power supply, the 220V alternating current is converted to the end that direct current is connected the elementary winding of step-down transformer on the one hand after rectification and filter circuit are handled, link to each other through the voltage input end of resistance with a pwm chip on the other hand; The pwm signal output of described pwm chip links to each other through the other end of a switch element with the elementary winding of described step-down transformer; The secondary winding of described step-down transformer is converted to primary voltage+12V and+the low-voltage DC output of 5V.
3. the two-in-one power circuit of liquid crystal TV set according to claim 2, it is characterized in that: described switch element is a N-channel MOS pipe, the grid of described metal-oxide-semiconductor connects the pwm signal output of described pwm chip, source ground, drain electrode connects the elementary winding of described step-down transformer.
4. according to the two-in-one power circuit of claim 2 or 3 described liquid crystal TV sets, it is characterized in that: in described backlight electric power, by the output of the secondary winding of step-down transformer+the 12V direct voltage connects the elementary winding of step-up transformer through switch chip, and then connects the backlight lamp tube socket of liquid crystal TV set by the secondary winding of step-up transformer.
5. the two-in-one power circuit of liquid crystal TV set according to claim 4, it is characterized in that: in described liquid crystal TV set, be provided with two backlight lamp tubes, described switch chip and step-up transformer all include two, + 12V direct voltage connects the voltage input end of two switch chips respectively, one of the output of two switch chips links to each other with the end of the same name of two elementary windings of step-up transformer, and another links to each other with the different name end of described two elementary windings of step-up transformer; The secondary winding of described two step-up transformers is connected one to one with the socket of two backlight lamp tubes.
6. the two-in-one power circuit of liquid crystal TV set according to claim 5, it is characterized in that: the switch controlling signal of described backlight electric power is by the GPIO mouth output of CPU on the master control borad, the GPIO mouth of described CPU connects the control end of a switching circuit, gating passage one end of described switching circuit connects described step-down transformer output+5V DC power supply, the other end connects the power end of an inverter INVERTER, and the pwm signal output of described inverter INVERTER connects the output control terminal of described switch chip.
7. the two-in-one power circuit of liquid crystal TV set according to claim 6, it is characterized in that: described switching circuit is connected realization by a NPN type triode with a positive-negative-positive triode; Wherein, the base stage of NPN type triode connects the GPIO mouth of described CPU, grounded emitter, and collector electrode connects the base stage of described positive-negative-positive triode, emitter connection+5V the direct voltage of described positive-negative-positive triode, collector electrode connects the power end of described inverter INVERTER.
8. the two-in-one power circuit of liquid crystal TV set according to claim 7, it is characterized in that: the signal input end of described inverter INVERTER receives the brightness regulated signal that CPU sends, and changes the pwm signal duty ratio of described inverter INVERTER output according to the magnitude of voltage of input signal.
9. the two-in-one power circuit of liquid crystal TV set according to claim 8, it is characterized in that: described switch chip adopts N+P combination metal-oxide-semiconductor switch chip to realize, the model of inverter INVERTER is BIT3105, the source S 1 of two metal-oxide-semiconductor switch chips is connection+12V direct voltage all, grid G 1 links to each other with POUT2, the POUT1 end of inverter BIT3105 respectively, grid G 2 links to each other with NOUT2, the NOUT1 end of inverter BIT3105 respectively, and drain D 1, D2 connect the elementary winding of described step-up transformer.
10. according to the two-in-one power circuit of claim 2 or 9 described liquid crystal TV sets, it is characterized in that: the model of described pwm chip is SG6841S.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520125565 CN2836374Y (en) | 2005-12-05 | 2005-12-05 | 2-in-1 power supply circuit for liquid crystal TV set |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200520125565 CN2836374Y (en) | 2005-12-05 | 2005-12-05 | 2-in-1 power supply circuit for liquid crystal TV set |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2836374Y true CN2836374Y (en) | 2006-11-08 |
Family
ID=37301023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200520125565 Expired - Fee Related CN2836374Y (en) | 2005-12-05 | 2005-12-05 | 2-in-1 power supply circuit for liquid crystal TV set |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2836374Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106572565A (en) * | 2015-10-08 | 2017-04-19 | 深圳市金锐显数码科技有限公司 | Two-in-one power supply |
| CN107067508A (en) * | 2017-03-14 | 2017-08-18 | 深圳康佳信息网络有限公司 | A kind of intelligent electronic lock based on GSM |
-
2005
- 2005-12-05 CN CN 200520125565 patent/CN2836374Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106572565A (en) * | 2015-10-08 | 2017-04-19 | 深圳市金锐显数码科技有限公司 | Two-in-one power supply |
| CN107067508A (en) * | 2017-03-14 | 2017-08-18 | 深圳康佳信息网络有限公司 | A kind of intelligent electronic lock based on GSM |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106488607B (en) | Switching Power Supply and television set | |
| CN101765274B (en) | LED lamp and drive circuit | |
| CN102243850B (en) | Backlight source driving circuit, driving method thereof as well as liquid crystal television | |
| CN102740545B (en) | Constant voltage dimmable led driver | |
| CN106448577B (en) | A kind of backlight constant current driving plate and liquid crystal TV set | |
| CN107086026B (en) | A kind of constant-current circuit and television set driving LED backlight | |
| CN105323512B (en) | A kind of secondary control device of PFC power supplies | |
| CN106954315A (en) | The driving power supply and television set of a kind of connection in series-parallel LED light bar network | |
| CN101447737B (en) | Constant power output direct current transforming circuit | |
| CN201142635Y (en) | DC-AC inversion boosted circuit | |
| CN107197185A (en) | A kind of power supply for LCD TV | |
| CN105307305B (en) | A kind of LED power control device and television set | |
| CN202210400U (en) | Backlight drive circuit and liquid crystal TV set | |
| CN205160851U (en) | Two unification powers | |
| CN2836374Y (en) | 2-in-1 power supply circuit for liquid crystal TV set | |
| CN209402781U (en) | A kind of ultra-thin photovoltaic intelligent dimming power control circuit | |
| CN102779486A (en) | LED (Light-Emitting Diode) driving circuit capable of regulating current balance by negative voltage | |
| CN202713737U (en) | LED (Light Emitting Diode) driving circuit capable of regulating current balance by negative voltage | |
| CN208623949U (en) | A kind of LED light source of the double light sources of twin voltage | |
| CN111371094B (en) | Double-power-supply system and television | |
| CN104735837A (en) | LED street lamp power supply without power frequency ripples and with APFC function | |
| CN209299157U (en) | Power output circuit, power circuit, display circuit, circuit board and display | |
| CN107295717A (en) | A kind of control circuit for LED lamp | |
| CN106991978A (en) | A kind of backlight drive control circuit based on LLC | |
| CN202058424U (en) | LED drive circuit and television |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |