CN101282084A - Power supply circuit and LCD device using the same - Google Patents
Power supply circuit and LCD device using the same Download PDFInfo
- Publication number
- CN101282084A CN101282084A CNA2007100739634A CN200710073963A CN101282084A CN 101282084 A CN101282084 A CN 101282084A CN A2007100739634 A CNA2007100739634 A CN A2007100739634A CN 200710073963 A CN200710073963 A CN 200710073963A CN 101282084 A CN101282084 A CN 101282084A
- Authority
- CN
- China
- Prior art keywords
- output
- diode
- inductance
- circuit
- input
- 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.)
- Pending
Links
Images
Abstract
A power supply circuit comprises two AC input ends, a transformer, an output circuit and an output end, the transformer comprises a primary winding and a secondary winding, the output circuit comprises a first inductance, a second inductance, a first diode, a second diode and a filter capacitor, the two AC input ends are respectively connected to the two ends of the primary winding, the one end of the secondary winding is connected in series to the first inductance, then is connected to the output end, the other end is connected in series to the second inductance, then is connected to the output end, the first diode positive pole is connected to one end of the secondary winding, the negtive pole is connected to the ground, the second diode positive pole is connected to the other end of the secondary winding, the negtive pole is connected to the ground, the filter capacitor is connected between the output end and the ground. The power supply circuit has advantage of high electric energy utilance. The invention also provides a LCD device using the power supply circuit.
Description
Technical field
The present invention relates to the liquid crystal indicator of a kind of power circuit and this power circuit of employing.
Background technology
Power circuit is widely used in the circuit of various electrical equipment, for different circuit provide working power.
See also Fig. 1, it is a kind of electrical block diagram of prior art power circuit.This power circuit 100 comprises two direct current inputs 101,102, a full-bridge circuit 110, a transformer 120, an output circuit 130 and an output 140.
This full-bridge circuit 110 comprises first field effect transistor 111, second field effect transistor 112, the 3rd field effect transistor 113 and the 4th field effect transistor 114 that four full-bridge forms connect, and the grid of these four field effect transistor is controlled its conducting by control signal respectively and ended.This transformer 120 comprises a primary winding 121 and a level winding 122.Two inputs of this full-bridge circuit 110 i.e. this two dc supply input 101,102, and two outputs of this full-bridge circuit 110 are connected to two inputs of this primary winding 121 respectively.
This output circuit 130 comprises one first diode 131, one second diode 132 and a filter capacitor 133.Of the same name the rectifying behind this first diode 131 of series connection of this secondary winding transformer 122 is electrically connected to this output 140, the different name of this secondary winding transformer 122 is proper to be electrically connected to this output 140 behind this second diode 132 of series connection, a tap (not indicating) is drawn at these secondary winding transformer 122 middle parts, this tap is divided into partly LS2 of the LS1 of first and second with this time utmost point winding 122, and this tap ground connection.This filter capacitor 133 holds for electrode points, and its positive electrical is connected to this output 140, minus earth.
When direct current is imported by this two direct currents input 101,102, under control signal control, it all is 50% alternating current that this full-bridge circuit 110 converts this direct current to one-period property generating positive and negative voltage duty ratio, and import this primary winding 121, through exporting by this output circuit 130 after these transformer 120 transformations.Detailed process is as follows: the end of the same name of this elementary winding 121 is input as positive voltage in first cycle, the end induced voltage of the same name of this secondary winding 122 is a positive voltage, the centre tap earthed voltage is always zero, and the different name end is a negative voltage, these first diode, 131 normal shock conductings.This moment, the first part LS1 of this secondary winding 122 was equivalent to a power supply, and by these output 140 outputs, this voltage is also to these filter capacitor 133 chargings simultaneously via this first diode 131 for voltage.In second cycle, the end of the same name of this elementary winding 121 is input as negative voltage, the end induced voltage of the same name of this secondary winding 122 is for negative, the different name terminal voltage is for just, these second diode, 132 normal shock conductings, this moment, the second part LS2 of this secondary winding 122 was equivalent to a power supply, and voltage, also charges to this filter capacitor 133 by these output 140 outputs simultaneously via this second diode 132.Positive voltage all is output as outside electrical appliance by this output 140 in first cycle and second cycle provides power supply, this filter capacitor 133 also provides energy to outside electrical appliance discharge simultaneously, thereby the output voltage of this output 140 is a comparatively pure direct voltage.
Said process is the operation principle of this power circuit one-period process, and this process realizes the function of its stabilized power supply constantly repeatedly.
But, when this power circuit 100 is that electrical appliance (as liquid crystal indicator) is when providing electric energy, no matter this power circuit 100 is operated in first cycle or second cycle, this secondary winding 122 is that the part of externally fed only is the LS1/ of first second LS2 partly as power supply, the second portion LS2/ first part LS1 that does not do power supply is in idle state, owing to itself have parasitic capacitance and self-resistance in each winding, parasitic capacitance and self-resistance and secondary winding winding 122 itself are formed the loop, the induced voltage of not being the second portion LS2/ first part LS1 of power supply can discharge by the loop that parasitic capacitance and self-resistance are formed, cause waste of electric energy on the one hand, this power circuit 100 self temperature is raise, quicken its aging speed and reduce its functional reliability.In addition, owing in every half period, have only the partly transmission of LS1 participation energy of second portion LS2/ first of this secondary winding 122, magnetic energy transmission is slower in this transformer 120, thereby strengthens eddy current loss and residual loss in this transformer 120, causes waste of energy equally.
Summary of the invention
In order to overcome the lower problem of prior art power circuit utilization rate of electrical, be necessary the power circuit that provides a kind of utilization rate of electrical higher.
Also be necessary to provide a kind of liquid crystal indicator that adopts this power circuit.
A kind of power circuit, it comprises two alternating current inputs, one transformer, one output circuit and an output, this transformer comprises an elementary winding and a level winding, this output circuit comprises one first inductance, one second inductance, one first diode, one second diode and a filter capacitor, this two alternating currents input is connected to the two ends of this elementary winding respectively, this secondary winding one end is connected and is electrically connected to this output behind this first inductance, the other end is connected and is electrically connected to this output behind this second inductance, this first diode cathode is connected to an end of this secondary winding, minus earth, this second diode cathode is connected to the other end of this secondary winding, minus earth, this filter capacitor is connected between this output and the ground.
A kind of liquid crystal indicator, it comprises a power circuit and a display panels, this power circuit comprises two alternating current inputs, one transformer, one output circuit and an output, this transformer comprises an elementary winding and a level winding, this output circuit comprises one first inductance, one second inductance, one first diode, one second diode and a filter capacitor, this two alternating currents input is connected to the two ends of this elementary winding respectively, this secondary winding one end is connected and is electrically connected to this output behind this first inductance, the other end is connected and is electrically connected to this output behind this second inductance, this first diode cathode is connected to an end of this secondary winding, minus earth, this second diode cathode is connected to the other end of this secondary winding, minus earth, this filter capacitor is connected between this output and the ground, this display panels comprises a power input, and the output of this power circuit is electrically connected to the power input of this display panels.
Compare prior art, in the design of this power circuit output circuit, any time, this secondary winding integral body all participated in external power supply, make this transformer reduce internal loss, utilization rate of electrical is higher, and it is stronger to drive load capacity, increases the stability of this power circuit simultaneously.
In the liquid crystal indicator of the present invention, adopt this power circuit, improve the utilance of electric energy, increase the stability of this liquid crystal indicator as power supply circuits.
Description of drawings
Fig. 1 is a kind of electrical block diagram of prior art power circuit.
Fig. 2 is the electrical block diagram of the power circuit first true mode of the present invention.
Fig. 3 is the electrical block diagram of power circuit second execution mode of the present invention.
Fig. 4 is the block diagram of liquid crystal indicator of the present invention.
Embodiment
See also Fig. 2, it is the electrical block diagram of power circuit first execution mode of the present invention.This power circuit 200 comprises two direct current inputs 201,202, a full-bridge circuit 210, a transformer 220, an output circuit 230 and an output 240.
This full-bridge circuit 210 comprises first field effect transistor 211, second field effect transistor 212, the 3rd field effect transistor 213 and the 4th field effect transistor 214 that four full-bridge forms connect.This transformer 220 comprises a primary winding 221 and a level winding 222.
Two inputs of this full-bridge circuit 210 i.e. this two dc supply input 201,202, this first field effect transistor 211, second field effect transistor 212, the 3rd field effect transistor 213 and the 4th field effect transistor 214 all are metal oxide semiconductor field effect tube (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), it all is a NPN type field effect transistor, and its grid is controlled its conducting by control signal respectively and by with as switch element.Two outputs of this full-bridge circuit 210 are connected to two ends of this primary winding 221 respectively.
This output circuit 230 comprises one first diode 231, one second diode 232, a filter capacitor 233, one first inductance 234 and one second inductance 235.The end of the same name of this secondary winding 222 is drawn two branch roads, and wherein a branch road is connected and is electrically connected to this output 240 behind this first inductance 234, these first diode, 231 back ground connection of another branch road differential concatenation.The different name end of this secondary winding 222 is drawn two branch roads, and wherein a branch road is connected and is electrically connected to this output 240 behind this second inductance 235, these second diode, 232 back ground connection of another branch road differential concatenation.This filter capacitor 233 is jumbo solid ceramic electrode capacitance, and better filter effect is provided, and its positive electrical is connected to this output 240, minus earth.
When extraneous direct current via this two direct currents input 201, during 202 these full-bridge circuits 210 of input, under the control of control signal, it all is 50% alternating voltage that this full-bridge circuit 210 is converted into one-period property generating positive and negative voltage duty ratio with this direct voltage, and import this primary winding 221, because electromagnetic induction effect, this secondary winding 222 produces induced voltage and externally exports as power supply, detailed process is as follows: at positive half period, first diode 211 and 214 conductings of the 4th diode of this full-bridge circuit 210, this elementary winding 221 of voltage input, this secondary winding 222 produces induced voltage, its end of the same name is a positive voltage, the different name end is a negative voltage, electric current flow into this first inductance 234 locate can and by 234 outputs of this first inductance, on one side by these output 240 output dc voltages, Yi Bian be these filter capacitor 233 chargings, electric current flows into this secondary winding 222 formation loops via these second diode, 232 backs then then.At negative half-cycle, these second diode 212 and 213 conductings of the 3rd diode, voltage is to import this elementary winding 221 in the other direction, and the induced voltage of this secondary winding 222 produces sudden change, and its end of the same name is a negative voltage, and the different name end is a positive voltage.After these secondary winding 222 different name end electric currents flow into this second inductance 235, by this output 240 provide voltage on one side, be these filter capacitor 233 chargings on one side, flow into this secondary winding 222 by this first diode 231 at last and constitute the loop.Because the electric current of inductance can not suddenly change, the electric current of this first inductance 234 keeps original direction, continue as this output 240 electric current is provided, 233 of this filter capacitors externally discharge, remedy the external power supply instability that these first inductance, 234 current attenuations cause, make output dc voltage more stable, discharge until the electric energy of this first inductance 234 and this filter capacitor 233 and finish.
Said process is the course of work of this power circuit in 200 one-periods, and this process cycle repeats, for electrical appliance provides galvanic current.
Compare prior art, because in the design of the output loop of this power circuit 200, any time, these secondary winding 222 integral body all participated in external power supply, make this transformer 220 reduce internal loss, utilization rate of electrical is higher, and it is stronger to drive load capacity, increases the stability of this power circuit 200 simultaneously.
See also Fig. 3, it is the electrical block diagram of power circuit second execution mode of the present invention.This power circuit 300 is different with the first execution mode power circuit 200 be in: this output circuit 330 further comprises one the 3rd diode 336 and one the 4th diode 337.Secondary winding 322 ends of the same name of this transformer 320 connect the 3rd diode 336 and be electrically connected to this output 340 of this first inductance 334 back forwards of connecting, these secondary winding 322 different name ends connect the 3rd diode 336 and be electrically connected to this output 340 of these first inductance, 334 back forwards of connecting.
The effect of the 3rd diode 336 and the 4th diode 337 is: the sense of current that limits this first inductance 334 and second inductance 335 is that folk prescription is to flowing, the electric current, the voltage that prevent this first inductance 334 and this second inductance 335 disturb, and make output circuit more stable.
See also Fig. 4, it is the block diagram of liquid crystal indicator of the present invention.This liquid crystal indicator 400 comprises a direct current power supply 410, a power circuit 420 and a display panels 430.This DC power supply 410 comprises two DC output end 411,412, this power circuit 420 can be any one of above-mentioned power circuit 200,300, it comprises two direct current inputs 421,422 and an output 423, and this display panels 430 comprises a power input 431.Two DC output end 411,412 of this DC power supply 410 are electrically connected to two direct current inputs 421,422 of this power circuit respectively, after this power circuit 422 changes the direct voltage of this DC power supply 410 into these display panels 430 work needed direct voltage, by these DC output end 423 outputs and by these power input 431 these display panels 430 of input, required for these display panels 430 work.
The power circuit 420 of this liquid crystal indicator 400 can reduce internal loss, improves the utilance of electric energy, and this power circuit 420 has higher stability, can improve the stability of this liquid crystal restraint device.
Claims (10)
1. power circuit, it comprises two alternating current inputs, one transformer, one output circuit and an output, this transformer comprises an elementary winding and a level winding, this output circuit comprises one first inductance, one second inductance, one first diode, one second diode and a filter capacitor, this two alternating currents input is connected to two ends of this elementary winding respectively, this secondary winding one end is connected and is electrically connected to this output behind this first inductance, the other end is connected and is electrically connected to this output behind this second inductance, this first diode cathode is connected to an end of this secondary winding, minus earth, this second diode cathode is connected to the other end of this secondary winding, minus earth, this filter capacitor is connected between this output and the ground.
2. power circuit as claimed in claim 1 is characterized in that: this filter capacitor is an electrode capacitance, and this filter capacitor positive electrical is connected to this output, minus earth.
3. power circuit as claimed in claim 1, it is characterized in that: further comprise two direct current inputs and an input circuit, direct current enters this input circuit via this two direct currents input, this input circuit is converted to an alternating current with this direct current, and this alternating current is imported this two alternating currents input.
4. power circuit as claimed in claim 3 is characterized in that: this input circuit is a bridge circuit of being made up of four switch elements.
5. power circuit as claimed in claim 1, it is characterized in that: further comprise one the 3rd diode and one the 4th diode, this first inductance forward is connected and is electrically connected to this output behind the 3rd diode, and this second inductance forward is connected and is electrically connected to this output behind the 4th diode.
6. liquid crystal indicator, it comprises a power circuit and a display panels, this power circuit comprises two alternating current inputs, one transformer, one output circuit and an output, this transformer comprises an elementary winding and a level winding, this output circuit comprises one first inductance, one second inductance, one first diode, one second diode and a filter capacitor, this two alternating currents input is connected to two ends of this elementary winding respectively, this secondary winding one end is connected and is electrically connected to this output behind this first inductance, the other end is connected and is electrically connected to this output behind this second inductance, this first diode cathode is connected to an end of this secondary winding, minus earth, this second diode cathode is connected to the other end of this secondary winding, minus earth, this filter capacitor is connected between this output and the ground, this display panels comprises a power input, and the output of this power circuit is electrically connected to the power input of this display panels.
7. liquid crystal indicator as claimed in claim 6 is characterized in that: this filter capacitor is an electrode capacitance.This filter capacitor positive electrical is connected to this output, minus earth.
8. liquid crystal indicator as claimed in claim 6, it is characterized in that: this power circuit further comprises two direct current inputs and an input circuit, direct current enters this input circuit via this two direct currents input, this input circuit is converted to an alternating current with this direct current, and this alternating current is imported this two alternating currents input.
9. liquid crystal indicator as claimed in claim 8 is characterized in that: this input circuit is a bridge circuit of being made up of four switch elements.
10. liquid crystal indicator as claimed in claim 6, it is characterized in that: this power circuit further comprises one the 3rd diode and one the 4th diode, this first inductance forward is connected and is electrically connected to this output behind the 3rd diode, and this second inductance forward is connected and is electrically connected to this output behind the 4th diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100739634A CN101282084A (en) | 2007-04-06 | 2007-04-06 | Power supply circuit and LCD device using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100739634A CN101282084A (en) | 2007-04-06 | 2007-04-06 | Power supply circuit and LCD device using the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101282084A true CN101282084A (en) | 2008-10-08 |
Family
ID=40014416
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007100739634A Pending CN101282084A (en) | 2007-04-06 | 2007-04-06 | Power supply circuit and LCD device using the same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101282084A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102751890A (en) * | 2011-04-18 | 2012-10-24 | 鸿富锦精密工业（深圳）有限公司 | Alternating-current rectification circuit and power circuit using same |
| CN107134929A (en) * | 2017-06-30 | 2017-09-05 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
| CN107659155A (en) * | 2017-08-10 | 2018-02-02 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
| CN107659159A (en) * | 2017-08-10 | 2018-02-02 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
-
2007
- 2007-04-06 CN CNA2007100739634A patent/CN101282084A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102751890A (en) * | 2011-04-18 | 2012-10-24 | 鸿富锦精密工业（深圳）有限公司 | Alternating-current rectification circuit and power circuit using same |
| CN107134929A (en) * | 2017-06-30 | 2017-09-05 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
| CN107659155A (en) * | 2017-08-10 | 2018-02-02 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
| CN107659159A (en) * | 2017-08-10 | 2018-02-02 | 苏州汇川联合动力系统有限公司 | Two-way DC converter and bidirectional, dc conversion control method |
| CN107659159B (en) * | 2017-08-10 | 2019-12-17 | 苏州汇川联合动力系统有限公司 | Bidirectional DC converter and bidirectional DC conversion control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102820765B (en) | Bias voltage generation circuit and switch power supply with bias voltage generation circuit | |
| CN102882359B (en) | Bias voltage generation circuit and switching power supply using same | |
| CN108572276B (en) | Wireless resonant power transmitter and method of peak-to-peak voltage detection therein | |
| CN102044971B (en) | Self-excited switching power supply circuit | |
| CN103546021A (en) | Current feedback method, current feedback circuit, driving circuit and switching power source | |
| CN103731027B (en) | Single-stage step-down conversion circuit | |
| CN102882410A (en) | Single-phase seven-level inverter | |
| CN101282084A (en) | Power supply circuit and LCD device using the same | |
| CN103236786B (en) | A kind of equalizer circuit and inverter | |
| CN203858288U (en) | Zero-cross detection circuit and power factor correction circuit | |
| CN203055409U (en) | Led backlight drive circuit and liquid crystal display device | |
| CN202068327U (en) | Boost converter | |
| CN101860180A (en) | MOS (Metal Oxide Semiconductor) driving device and power supply module | |
| CN206060166U (en) | A kind of point is mended adjuster circuit | |
| CN104749426A (en) | Zero crossing detection circuit and power factor correction circuit | |
| CN103296911B (en) | Single pipe resonant type soft switch inversion circuit | |
| CN109951183A (en) | A kind of chip, signal shift circuit and electronic equipment | |
| CN103001498B (en) | Backlight-driven direct-current booster topology circuit | |
| CN101572491B (en) | Switch power circuit and operation method thereof | |
| CN208386255U (en) | A kind of wireless electric energy transmission device with constant current output characteristic | |
| CN102882411A (en) | Single-phase seven-level inverter | |
| CN201616776U (en) | Inverter with two switch elements | |
| CN103078481B (en) | Input and output voltage fluctuation suppressing circuit | |
| CN101834533A (en) | Power module | |
| CN202364142U (en) | Simple DC stabilized power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Open date: 20081008 |