CN100454731C - Current driver - Google Patents
Current driver Download PDFInfo
- Publication number
- CN100454731C CN100454731C CNB031139655A CN03113965A CN100454731C CN 100454731 C CN100454731 C CN 100454731C CN B031139655 A CNB031139655 A CN B031139655A CN 03113965 A CN03113965 A CN 03113965A CN 100454731 C CN100454731 C CN 100454731C
- Authority
- CN
- China
- Prior art keywords
- resistance
- wave generator
- comparator
- output
- driving device
- 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
Landscapes
- Led Devices (AREA)
- Amplifiers (AREA)
Abstract
The present invention relates to a current driver which comprises a first comparator, a second comparator, a low-frequency sawtooth wave generator, a high-frequency sawtooth wave generator, an adjustable magnification ratio amplifier, a field effect transistor, a voltage source of time sequence control, a voltage source of amplitude control and an auxiliary power supply. A low-frequency sawtooth wave signal generated by the low-frequency sawtooth wave generator and a time sequence control input generated by the voltage source of time sequence control are inputted into the input end of the first comparator; output signals of the first comparator are inputted into one input end of the adjustable magnification ratio amplifier, and an amplitude control signal generated by the voltage source of amplitude control is inputted into the other input end of the adjustable magnification ratio amplifier; an output signal of the adjustable magnification ratio amplifier and a high-frequency sawtooth wave signal generated by the high-frequency sawtooth wave generator are inputted into the input end of the second comparator of which the output end is connected with a grid of the field effect transistor; the auxiliary power supply is connected with a source electrode of the field effect transistor; a drain electrode of the field effect transistor is used for outputting drive current.
Description
[technical field]
The present invention relates to a kind of current driving device, refer in particular to a kind of pulse-width modulation type current driving device.
[background technology]
See also Fig. 1, it is a kind of drive unit of the prior art, its load is a light-emitting diode, wherein voltage source 10 applies a voltage on the light emitting diode matrix 30 by current-limiting resistance 20, this light emitting diode matrix 30 comprises the capable n row of a m light-emitting diode 31, and the resistance of this current-limiting resistance 20 is R, and the voltage of voltage source 10 is U, the main line electric current is I, and the equivalent resistance of single light-emitting diode 31 is Rs.
Its voltage-current characteristic is represented with following formula:
U-m*Von＝I(R+Rs(m/n))
This formula is reduced to:
U-Vx=I (R+Rx) wherein, Vx=m*Von, Rx=Rs (m/n)
Because the existence of the starting resistor Von of light-emitting diode 31, electric current I is the linear change with the change of voltage U not, and when becoming original two times when voltage U, the electric current I variation is less than original two times.Even therefore drive fixing light emitting diode matrix, its driving voltage and drive current are not linear yet.So be difficult to finish the accurate control of the drive current of light-emitting diode.
And when the light emitting diode matrix on-fixed that drives, when being the variation of its array format or light-emitting diode number, be that Vx and Rx are when changing, for satisfying suitable light-emitting diode electrical installation environment, often need driving voltage U and current-limiting resistance R are adjusted, equally also can't when driving voltage changes, linearity change drive current.When the application that is used for load variations, a lot of inconvenience are arranged, equally also be difficult to finish accurate control the drive current of light-emitting diode.
In addition, for the application that need show according to sequential, also needing increases sequential control circuit again, and makes entire circuit very complicated.
[summary of the invention]
Be difficult to accurate controlling and driving electric current in the prior art and increase the defective that sequential control circuit can make entire circuit become complicated for overcoming, the invention provides the current driving device that a kind of accurately controlling and driving electric current also can carry out sequencing control simply.
The technical scheme of technical solution problem of the present invention is: a kind of current driving device is provided, and it comprises a first party wave generator, a second party wave generator, a field-effect transistor and an accessory power supply.The output of first party wave generator is connected to the input of second party wave generator, the output of second party wave generator is connected to the grid of field-effect transistor, accessory power supply is connected with the source electrode of field-effect transistor, the drain electrode output driving current of field-effect transistor.
Compare with prior art, the advantage of current driving device of the present invention is to use high-frequency pulsed width modulation can realize accurate control to the drive current size, uses the low frequency pulse-width modulation can realize sequencing control to drive current again simply.
[description of drawings]
Fig. 1 is the schematic diagram of drive unit in the prior art.
Fig. 2 is the schematic diagram of current driving device of the present invention.
Fig. 3 is the oscillogram of current driving device of the present invention.
Fig. 4 is the structure chart of current driving device of the present invention.
Fig. 5 is the circuit diagram of the low frequency saw-toothed wave generator of current driving device of the present invention.
Fig. 6 is the schematic diagram of the adjustable amplification ratio amplifier of current driving device of the present invention.
Fig. 7 is the oscillogram of first comparator of current driving device of the present invention.
Fig. 8 is the oscillogram of the adjustable amplification ratio amplifier of current driving device of the present invention.
Fig. 9 is second comparator of current driving device of the present invention and the oscillogram of field-effect transistor.
[embodiment]
See also Fig. 2, current driving device of the present invention comprises a first party wave generator 100, second party wave generator 200, field-effect transistor 3, an accessory power supply 9 and a current-limiting resistance 11,12.The output output low frequency square-wave signal Vo1 of first party wave generator 100 is with the switching sequence of controlling and driving electric current, this output is connected to the input of second party wave generator 200, the output output high-frequency square-wave signal Vo2 of second party wave generator 200 is with the size of controlling and driving electric current, this output is connected to the grid of field-effect transistor 3, accessory power supply 9 is connected with the source electrode of field-effect transistor 3, the drain electrode output driving current Io2 of field-effect transistor 3.
Seeing also Fig. 3, is the oscillogram of current driving device of the present invention.The high-frequency square-wave signal cycle of setting 200 generations of second party wave producer is T, and the low-frequency square-wave signal cycle that first party wave producer 100 produces is 10T.In cycle, determine the switching sequence of drive current Io2 at two low-frequency square-wave signals by low-frequency square-wave signal Vo1; Size by high-frequency square-wave signal Vo2 decision drive current Io2 under opening.
Above-mentioned setting such as low-frequency square-wave signal cycle are that 10 times of high-frequency square-wave signal cycle etc. are only for setting forth concrete parameter of the present invention.When practical application, the low-frequency square-wave signal cycle can be other multiple in high-frequency square-wave signal cycle.
Seeing also Fig. 4, is another execution mode of current driving device of the present invention, and it comprises a first party wave generator 100,200, one field-effect transistor of second party wave generator 3, an accessory power supply 9 and a current-limiting resistance 11,12.First party wave generator 100 is made of first comparator 1, low frequency saw-toothed wave generator 4, sequencing control voltage source 7; Second party wave generator 200 is made of second comparator 2, high frequency saw-toothed wave generator 5, adjustable amplification ratio amplifier 6, amplitude control voltage source 8.The timing control signal that low frequency sawtooth signal that low frequency saw-toothed wave generator 4 produces and sequencing control voltage source 7 produce inputs to the input of first comparator 1, the output signal of first comparator 1 inputs to an input of adjustable amplification ratio amplifier 6, the amplitude control signal that amplitude control voltage source 8 produces inputs to another input of adjustable amplification ratio amplifier 6, the high frequency sawtooth signal that the output signal of adjustable amplification ratio amplifier 6 and high frequency saw-toothed wave generator 5 produce inputs to the input of second comparator 2, the output of second comparator 2 is connected to the grid of field-effect transistor 3, accessory power supply 9 is connected to the source electrode of field-effect transistor 3 by current-limiting resistance 11, and the drain electrode of field-effect transistor 3 is by resistance 12 output driving currents.
See also Fig. 5, it is the circuit diagram of low frequency saw-toothed wave generator 4, the inverting input of operational amplifier 401 connects earth resistance 412 back ground connection, the Uo voltage that the U1 voltage that its in-phase input end is fed back by second resistance 410 and first resistance 408 feed back determines jointly, its output termination the 3rd resistance 414.Operational amplifier 401, earth resistance 412, second resistance 410, first resistance 408, the 3rd resistance 414 constitute the zero passage voltage comparator.The inverting input of operational amplifier 402 is by two loops, be the first integral resistance 404 and first diode 405, second integral resistance 406 and second diode 407, be connected to double voltage stabilizing tube 409, also be connected simultaneously, the output output sawtooth waveforms Uo of operational amplifier 402 with electric capacity 403.Operational amplifier 402, first integral resistance 404 and first diode 405, second integral resistance 406 and second diode 407, double voltage stabilizing tube 409, electric capacity 403 constitute the zero passage integrator.The in-phase input end of the operational amplifier 401 of this zero passage voltage comparator is connected to an end of first resistance 408 and second resistance 410 respectively, and its output connects an end of the 3rd resistance 414; The inverting input of the operational amplifier 402 of this zero passage integrator respectively with this first integral resistance 404, one end of second integral resistance 406 and electric capacity 403 is connected, the output of the operational amplifier 402 of this zero passage integrator is connected to the other end of first resistance 408 of the other end of this electric capacity 403 and this zero passage voltage comparator respectively, the other end of this first integral resistance 404 is connected to the negative electrode of this first diode 405, the other end of this second integral resistance 406 is connected to the anode of this second diode 407, the anode of this first diode 405 is connected to the other end of the 3rd resistance 414 respectively, the other end of this second resistance 410, the negative electrode of this second diode 407, and an end of this double voltage stabilizing tube 408, the other end ground connection of this double voltage stabilizing tube 409.
This circuit also can be used as the circuit of high frequency saw-toothed wave generator 5, because this circuit produces the sawtooth wave frequency by resistance 408,410, integrating resistor 404,406 and electric capacity 403 decisions, and mainly by resistance 408,410, integrating resistor 404 and electric capacity 403 decisions, so the circuit of high frequency saw-toothed wave generator 5 can be done to adjust accordingly and realize to the parameter of these several assemblies.
The saw-toothed wave generator that current adjusting device of the present invention adopted is not limited to the low frequency saw-toothed wave generator 4 and the high frequency saw-toothed wave generator 5 of present embodiment, and other saw-tooth wave generating circuit is also applicable.
See also Fig. 6, the adjustable amplification ratio amplifier 6 that present embodiment adopts is the photo resistance amplifier, and it comprises light-emitting diode 601, photo resistance 602, resistance 603, operational amplifier 604 and resistance 605.Photo resistance 602 resistances are R2, and resistance 603 resistances are R1, and input signal is Vo1, and output signal is Vi2.Light-emitting diode 601 is connected to one and adjusts voltage source 606 to receive the adjustment signal V2 that this adjustment voltage source 606 is produced, light-emitting diode 601 is luminous to expose to photo resistance 602, photo resistance 602 two ends are connected with output with the inverting input of operational amplifier 604 respectively, input signal Vo1 is connected to the inverting input of operational amplifier 604 by a resistance 603, and the in-phase input end of operational amplifier 604 is by another resistance 605 and ground connection.
The variation of adjusting signal V2 causes that the luminous intensity of light-emitting diode 601 changes, and causes the resistance of photo resistance 602 to change, and selects suitable device and parameter, photo resistance 602 resistance R2 to be proportional to and adjusts signal V2, i.e. R2=KV2 (K is a constant); Simultaneously, can obtain by the amplifier principle that output signal Vi2 and input signal Vo1 close is Vi2=-(R2/R1) Vo1; Therefore can draw: Vi2=-(KV2/R1) Vo1, promptly the amplification ratio of this amplifier is directly proportional with adjustment signal V2.
The adjustable amplification ratio amplifier 6 that the present invention adopts is not limited in the photo resistance amplifier, and the amplification ratio adjustable amplifier of other type also can adopt, and only needs the amplification ratio of this amplifier to be directly proportional with the adjustment signal.
Seeing also Fig. 7 to Fig. 9, is the oscillogram in each stage of current driving device of the present invention, and the high frequency sawtooth signal cycle of setting 5 generations of high frequency saw-toothed wave generator is T, and the low frequency sawtooth signal cycle that low frequency saw-toothed wave generator 4 produces is 10T.
Seeing also Fig. 7, is the input and output signal oscillogram of first comparator 1.The timing control signal V1 that sequencing control voltage source 7 produces is for adjusting voltage, and Vr1 is the low frequency sawtooth signal, and Vo1 is the output signal of comparator 1, and the low frequency sawtooth signal cycle is 10T.The sawtooth signal Vr1 that low frequency saw-toothed wave generator 4 produces and the timing control signal V1 of sequencing control voltage source 7 generations compare by first comparator 1, and as V1 during greater than sawtooth signal Vr1 transient voltage, first comparator 1 is output as high level; When adjusting voltage V1 less than sawtooth signal Vr1 transient voltage, first comparator 1 is output as low level.This signal is high level in the time at preceding 5T, and 5T is low level in the time in the back, promptly passes through the switching sequence of this output signal Vo1 Control current drive unit.
Seeing also Fig. 8, is the input and output signal oscillogram of adjustable amplification ratio amplifier 6.The output signal Vo1 of first comparator 1 is the input signal of adjustable amplification ratio amplifier 6, and the amplitude control signal V2 that amplitude control voltage source 8 produces is for adjusting signal, and output signal is Vi2, and this amplitude control voltage source 8 is this adjustment voltage source 606.Because the amplification ratio of adjustable amplification ratio amplifier 6 is directly proportional with the adjustment signal, and input signal Vo1 is a definite value, therefore the output signal of adjustable amplification ratio amplifier 6 and the relational expression of input signal are: Vi2=-(KV2/R1) Vo1=-(KVo1/R1) V2=LV2 (L is a constant), promptly output signal Vi2 is for adjusting the constant times of signal V2.
Seeing also Fig. 9, is the input and output signal oscillogram of second comparator 2 and field-effect transistor 3.Vi2, being the output signal of adjustable amplification ratio amplifier 6, is the input signal of second comparator 2, and Vr2 is the high frequency sawtooth signal, Vo2 is that the output signal of second comparator 2 also is the grid voltage of field-effect transistor 3 simultaneously, and Io2 is the output current of field-effect transistor 3 drain electrodes.The sawtooth signal Vr2 that high frequency saw-toothed wave generator 5 produces and the output signal Vi2 of adjustable amplification ratio amplifier 6 compare by second comparator 2, as the output signal Vi2 of adjustable amplification ratio amplifier 6 during greater than high frequency sawtooth signal Vr2 transient voltage, the output signal Vo2 of second comparator 2 is a high level; As the output signal Vi2 of adjustable amplification ratio amplifier 6 during less than high frequency sawtooth signal Vr2 transient voltage, the output signal Vo2 of second comparator 2 is a low level.The input of the grid of this output signal Vo2 self-field effect transistor 3, accessory power supply 9 is connected to the source electrode of field-effect transistor 3 by current-limiting resistance 11, and the drain electrode of field-effect transistor 3 is by resistance 12 output driving current Io2.
High frequency sawtooth signal Vr2 slope is a definite value, in each high frequency sawtooth period, the input signal Vi2 of second comparator 2 can be considered slow variation, therefore, the output signal Vo2 of second comparator 2 is directly proportional with the size of the input signal Vi2 of second comparator 2 time of high level, and the time of the drain electrode output current Io2 of field-effect transistor 3 is equal to the grid voltage Vo2 of field-effect transistor 3 is the time of high level, therefore time and second comparator, the 2 output signal Vo2 of output current Io2 of draining are directly proportional the time of high level, be directly proportional with the size of the input signal Vi2 of second comparator 2, i.e. T
Io2=MVi2 (M is a constant).Consult the analysis of Fig. 7: Vi2=LV2 (L is a constant) again, the input signal Vi2 of second comparator 2 has following formula: T for adjusting the constant times of signal V2
Io2=NV2 (N is a constant), the time T of the output current Io2 that promptly drains
Io2The size of the amplitude control signal V2 that produces with amplitude control voltage source 8 is directly proportional.
Consult Fig. 7 again, in low frequency sawtooth signal one-period time 10T, compared by timing control signal V1 and low frequency sawtooth signal Vr1, produce a preceding 5T time for opening, the signal of back 5T time for closing realized the sequencing control to drive current; And consult Fig. 9, in the 5T time of opening, by the time T of amplitude control signal V2 decision drain electrode output current Io2
Io2
In this execution mode, first comparator 1, low frequency saw-toothed wave generator 4, sequencing control voltage source 7 constitute first party wave generator 100; Second comparator 2, high frequency saw-toothed wave generator 5, adjustable amplification ratio amplifier 6, amplitude control voltage source 8 constitute second party wave generator 200.
First party wave generator 100 of the present invention and second party wave generator 200 are not limited in the constituted mode of present embodiment, and the first party wave generator 100 and the second party wave generator 200 of other type also can adopt.
Above-mentioned setting such as low frequency sawtooth signal cycle are that 10 times of high frequency sawtooth signal cycle etc. only are for setting forth a concrete parameter of the present invention.When practical application, the cycle of low frequency sawtooth signal can be other multiple in high frequency sawtooth signal cycle.
The load of current driving device of the present invention can be light-emitting diode, CCFL (CathodeFluorescence Lamp, cold cathode fluorescent lamp) etc.
Current driving device of the present invention and its load that is driven can be used as display and other light source as the display unit of usefulness such as vehicle, boats and ships and airborne vehicle.
Claims (8)
1. current driving device, it is characterized in that: comprise a first party wave generator, a second party wave generator, a field-effect transistor and an accessory power supply, wherein, first party wave generator output is connected to the input of second party wave generator, the output of second party wave generator is connected to the grid of field-effect transistor, accessory power supply is connected with the source electrode of field-effect transistor, the drain electrode output driving current of field-effect transistor, the frequency of first square-wave signal that this first party wave generator produces is lower than the frequency of second square-wave signal of this second party wave generator generation, and this first party wave generator is used to realize the sequencing control to this drive current, and this second party wave generator is used to realize the size control to this drive current.
2. current driving device as claimed in claim 1, it is characterized in that this first party wave generator comprises: one first comparator, a low frequency saw-toothed wave generator, a sequencing control voltage source, wherein, the low frequency sawtooth signal of low frequency saw-toothed wave generator generation inputs to an input of first comparator, the timing control signal of sequencing control voltage source generation inputs to another input of first comparator.
3. current driving device as claimed in claim 1, it is characterized in that this second party wave generator comprises: an adjustable amplification ratio amplifier, an amplitude control voltage source, a high frequency saw-toothed wave generator, one second comparator, wherein, an input of this is adjustable amplification ratio amplifier is connected to the output of first comparator, the amplitude control signal that this amplitude control voltage source produces inputs to another input of this adjustable amplification ratio amplifier, the output of this is adjustable amplification ratio amplifier is connected to an input of this second comparator, and the high frequency sawtooth signal that this high frequency saw-toothed wave generator produces inputs to another input of this second comparator.
4. current driving device as claimed in claim 2 is characterized in that this low frequency saw-toothed wave generator comprises a zero passage voltage comparator, a zero passage integrator, and the output of zero passage integrator feeds back to the zero passage voltage comparator and produces the low frequency sawtooth signal; The zero passage voltage comparator of this low frequency saw-toothed wave generator comprises an operational amplifier, first resistance, second resistance, the 3rd resistance and an earth resistance, wherein, the inverting input of this operational amplifier passes through ground resistance earth, its in-phase input end is connected to an end of first resistance and second resistance respectively, and its output connects an end of the 3rd resistance; This zero passage integrator comprises an operational amplifier, an electric capacity, a first integral resistance, a second integral resistance, one first diode, one second diode and a double voltage stabilizing tube, the inverting input of the operational amplifier of this zero passage integrator respectively with this first integral resistance, one end of second integral resistance and electric capacity is connected, the output of the operational amplifier of this zero passage integrator is connected to the other end of first resistance of the other end of this electric capacity and this zero passage voltage comparator respectively, the other end of this first integral resistance is connected to the negative electrode of this first diode, the other end of this second integral resistance is connected to the anode of this second diode, the anode of this first diode is connected to the other end of the 3rd resistance respectively, the other end of this second resistance, the negative electrode of this second diode, and an end of this double voltage stabilizing tube, the other end ground connection of this double voltage stabilizing tube.
5. current driving device as claimed in claim 3 is characterized in that the load that this current driving device drives is a light-emitting diode.
6. current driving device as claimed in claim 3 is characterized in that the load that this current driving device drives is a cold-cathode fluorescence lamp.
7. current driving device as claimed in claim 3 is characterized in that this adjustable amplification ratio amplifier is the photo resistance amplifier.
8. current driving device as claimed in claim 7, it is characterized in that this photo resistance amplifier comprises a light-emitting diode, a photo resistance, an operational amplifier, a resistance and another resistance, wherein, this light-emitting diode is connected to this amplitude control voltage source to receive this amplitude control signal that this amplitude control voltage source is exported, this lumination of light emitting diode exposes to this photo resistance, these photo resistance two ends are connected with output with the inverting input of this operational amplifier respectively, the low-frequency square-wave signal that the output of first comparator is exported is connected to the inverting input of this operational amplifier by a resistance, and the in-phase input end of this operational amplifier is by another resistance and ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031139655A CN100454731C (en) | 2003-03-15 | 2003-03-15 | Current driver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB031139655A CN100454731C (en) | 2003-03-15 | 2003-03-15 | Current driver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1531176A CN1531176A (en) | 2004-09-22 |
| CN100454731C true CN100454731C (en) | 2009-01-21 |
Family
ID=34283871
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB031139655A Expired - Fee Related CN100454731C (en) | 2003-03-15 | 2003-03-15 | Current driver |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100454731C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102650651A (en) * | 2011-02-24 | 2012-08-29 | 株式会社爱德万测试 | Power supply apparatus for test apparatus |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100566163C (en) * | 2006-10-27 | 2009-12-02 | 中国科学院空间科学与应用研究中心 | A kind of current imposing sequence control circuit that is used for power amplifier |
| CN102045916A (en) * | 2009-10-15 | 2011-05-04 | 富准精密工业(深圳)有限公司 | Light emitting diode lamp and control circuit thereof |
| DE102015221636A1 (en) * | 2015-11-04 | 2017-05-04 | Robert Bosch Gmbh | A method of operating a metal oxide semiconductor field effect transistor |
| CN110534323A (en) * | 2019-09-27 | 2019-12-03 | 山东广域科技有限责任公司 | The three-phase transformer of on-load voltage regulation driving switch circuit and the application switching circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4452210A (en) * | 1981-09-21 | 1984-06-05 | Hitachi, Ltd. | Fuel injection valve drive circuit |
| CN1242925A (en) * | 1997-01-03 | 2000-01-26 | 艾利森电话股份有限公司 | Driver circuit, and method for operating same |
| US20010043113A1 (en) * | 2000-05-12 | 2001-11-22 | Taichi Hoshino | LED drive circuit |
| CN1370035A (en) * | 2001-02-08 | 2002-09-18 | 精工电子有限公司 | LED drive circuit |
-
2003
- 2003-03-15 CN CNB031139655A patent/CN100454731C/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4452210A (en) * | 1981-09-21 | 1984-06-05 | Hitachi, Ltd. | Fuel injection valve drive circuit |
| CN1242925A (en) * | 1997-01-03 | 2000-01-26 | 艾利森电话股份有限公司 | Driver circuit, and method for operating same |
| US20010043113A1 (en) * | 2000-05-12 | 2001-11-22 | Taichi Hoshino | LED drive circuit |
| CN1370035A (en) * | 2001-02-08 | 2002-09-18 | 精工电子有限公司 | LED drive circuit |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102650651A (en) * | 2011-02-24 | 2012-08-29 | 株式会社爱德万测试 | Power supply apparatus for test apparatus |
| CN102650651B (en) * | 2011-02-24 | 2015-05-13 | 株式会社爱德万测试 | Power supply apparatus for test apparatus and the test apparatus |
| US9188633B2 (en) | 2011-02-24 | 2015-11-17 | Advantest Corporation | Power supply apparatus for test apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1531176A (en) | 2004-09-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7633463B2 (en) | Method and IC driver for series connected R, G, B LEDs | |
| TWI236165B (en) | Driving device for light emitted diode string | |
| TWI391028B (en) | Light emitting diode module | |
| CN101569025B (en) | Light emitting diode driving apparatus | |
| CN101572978B (en) | Light emitting diode driving module | |
| Chiu et al. | A high accuracy current-balanced control technique for LED backlight | |
| CN201774715U (en) | Current feedback circuit and drive circuit of light-emitting diode (LED) lamp | |
| CN201114961Y (en) | Light control adjuster | |
| US11438979B2 (en) | LED driving circuit and LED driving method | |
| CN102209413A (en) | Current feedback circuit and LED (light-emitting diode) lamp drive circuit | |
| US8686652B2 (en) | Reference voltage generating circuit and LED driver circuit having the same therein | |
| CN107347222A (en) | Dimming driving circuit and its control method | |
| JP2007287964A (en) | Driving apparatus for light emitting element, light emitting apparatus, and driving method of same light emitting apparatus | |
| CN110446308A (en) | For controlling control circuit, driving circuit, LED lamp system and the control method of power transistor | |
| CN100454731C (en) | Current driver | |
| CN102111929A (en) | Circuit for controlling CC (Constant Current) driving and dimming of LED | |
| JP2011199220A (en) | Light emitting element driving device | |
| CN107592705A (en) | The LED drive circuit and light-dimming method of tunable optical | |
| CN114495848A (en) | LED backlight modulation method based on duty ratio reference point setting | |
| CN201116672Y (en) | Equal-current controllable light-emitting diode array circuit | |
| CN100395805C (en) | Light-emitting diode driving device | |
| CN202172518U (en) | Pulse width modulation burst dimming device | |
| CN101126846A (en) | LCD boosted circuit | |
| CN210429267U (en) | LED backlight driving circuit | |
| CN108712801B (en) | Constant power driving circuit and device with wide input voltage |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090121 Termination date: 20170315 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |