CN210405708U - Linear LED drive circuit for adjusting power and current - Google Patents
Linear LED drive circuit for adjusting power and current Download PDFInfo
- Publication number
- CN210405708U CN210405708U CN201822133173.7U CN201822133173U CN210405708U CN 210405708 U CN210405708 U CN 210405708U CN 201822133173 U CN201822133173 U CN 201822133173U CN 210405708 U CN210405708 U CN 210405708U
- Authority
- CN
- China
- Prior art keywords
- circuit
- voltage
- control circuit
- terminal
- current
- 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.)
- Active
Links
Images
Abstract
The utility model provides a non-stroboscopic LED drive circuit, which comprises a rectification circuit, a control circuit, a capacitor C, a sampling resistor R1 and a switch tube M; the rectification circuit is connected with an external alternating current power supply and is connected with the control circuit for supplying power; the control circuit is also connected with the two ends of the LED lamp string, the switch tube M and the positive end of the sampling resistor for sampling and driving control; one end of the capacitor C is connected with the positive end of the LED lamp string and the control circuit, and the other end of the capacitor C is grounded for storing and supplying energy. The LED driving circuit can eliminate stroboflash and meet the requirement of the market on LED illumination.
Description
Technical Field
The utility model relates to a LED illumination field, concretely relates to no stroboscopic LED drive circuit.
Background
In the field of LED lighting, there are LED current control, LED Power Factor (PF) regulation, LED strobe control, which often only adjusts one parameter of the LED, while the adjustment of one parameter can cause the deterioration of another parameter, for example, the stroboflash of the current high-voltage linear product is serious, if the stroboflash is reduced, if the simple parallel capacitor can cause the PF to be reduced, so the method is not preferable, generally adopts the large current charging when the voltage of the commercial power (sin wave voltage) is lower, and adopts the small current charging when the voltage is higher, the chip loss can be reduced (the chip loss is increased along with the increase of the voltage), and the stroboflash can be controlled to be about 30% on the premise of optimizing the efficiency in the prior art, but the stroboflash cannot meet the requirement of the market on the LED illumination, so that, adjusting both power and current parameters simultaneously to eliminate stroboflash is a problem that needs to be solved at present.
Novel content
In order to solve the technical problem, the utility model provides a no stroboscopic LED drive circuit, it can eliminate the stroboscopic, satisfies the requirement of market to the LED illumination.
The technical scheme is as follows:
a non-strobe LED drive circuit comprises a rectification circuit (10), a control circuit (20), a capacitor C, a sampling resistor R1 and a switch tube M; the rectifying circuit (10) is connected with an external alternating current power supply and is connected with the control circuit (20) for supplying power; the control circuit (20) is also connected with the two ends of the LED lamp string, the switch tube M and the positive end of the sampling resistor for sampling and driving control; one end of the capacitor C is connected with the positive end of the LED lamp string and the control circuit (20), and the other end of the capacitor C is grounded for storing and supplying energy.
Preferably, the control circuit (20) includes five terminals, namely a terminal B1, a terminal B2, a terminal B3, a terminal B4 and a terminal B5; the input end of the rectifying circuit (10) is connected with an external alternating current power supply, and the output end of the rectifying circuit is connected with the end B1 for power supply; the end B2 is connected with the positive end of the LED lamp string and the positive end of the capacitor C, and the negative end of the capacitor is grounded; the end B3 is connected with the negative end of the LED lamp string and the drain electrode of the switch tube M; the end B4 is connected with the grid electrode of the switching tube M; and the end B5 is connected with the sampling resistor and the source electrode of the switching tube, and the other end of the sampling resistor is grounded.
Preferably, the control circuit (20) includes a voltage-controlled current circuit (22) and a current control circuit (21), wherein the current control circuit (21) is provided with a terminal B4 and a terminal B5, and the voltage-controlled current circuit (22) is provided with a terminal B1, a terminal B2 and a terminal B3.
Preferably, the voltage control current circuit (22) comprises a voltage feedback circuit (221), a logic control circuit (222) and a charging current control circuit (223); the voltage feedback circuit (221) is provided with a terminal B3, the voltage feedback circuit outputs a voltage feedback signal to the logic control circuit (222) according to the voltage of the terminal B3, and the logic control circuit (222) outputs a current control signal to the charging current control circuit (223) according to the voltage feedback signal; the charging current control circuit (223) is provided with a terminal B1 and a terminal B2.
Preferably, the voltage feedback circuit (221) comprises a power tube M1, a power tube M2, a comparator P1 and a capacitor C2, wherein gates and collectors of the power tube M1 and the power tube M2 are interconnected; two comparison ends of a comparator P1 are respectively connected with a voltage VB3 and a first reference voltage Vref1 which obtain a B3 end, an output end is connected with gates of a power tube M1 and a power tube M2, an emitter of the power tube M1 is connected with a bias end bias1, and a source of the power tube M2 is connected with a bias end bias 2; the drains of the power tube M1 and the power tube M2 are connected with the capacitor C2 and output voltage feedback signals.
Preferably, the logic control circuit (222) comprises a voltage-current conversion circuit for converting the voltage feedback signal into a current control signal; the charging current control circuit (223) comprises an amplifier for amplifying a current control signal; the current control circuit (21) comprises a comparator for comparing the voltage of the sampling resistor with a reference voltage Vref 2.
Drawings
Fig. 1 is a circuit structure diagram of the LED driving circuit of the present invention;
fig. 2 and fig. 3 are working process diagrams of the LED driving circuit of the present invention;
fig. 4 is a circuit structure diagram of the control circuit of the present invention;
FIG. 5 is a circuit diagram of the medium voltage control current circuit according to the present invention;
FIG. 6 is a diagram of the operation process of the medium voltage control current circuit of the present invention;
fig. 7 is a circuit structure diagram of the medium voltage feedback circuit of the present invention;
fig. 8 is a circuit diagram of the charging current control circuit according to the present invention;
fig. 9 is a circuit structure diagram of the medium current control circuit of the present invention.
Detailed Description
The utility model provides a non-stroboscopic LED drive circuit, which comprises a rectification circuit 10, a control circuit 20, a capacitor C, a sampling resistor R1 and a switch tube M; the rectification circuit 10 is connected with an external alternating current power supply and is connected with a control circuit 20 for supplying power; the control circuit 20 is also connected with the two ends of the LED lamp string, the switch tube M and the positive end of the sampling resistor for sampling and driving control; one end of the capacitor C is connected with the positive end of the LED lamp string and the control circuit 20, and the other end of the capacitor C is grounded to store energy and supply power to the LED lamp string.
Further, as shown in fig. 1, the control circuit 20 includes five terminals, which are terminal B1, terminal B2, terminal B3, terminal B4 and terminal B5; the input end of the rectifying circuit 10 is connected with an external alternating current power supply, and the output end of the rectifying circuit is connected with the end B1 for power supply; the end B2 is connected with the positive end of the LED lamp string and the positive end of the capacitor C, and the negative end of the capacitor is grounded; the end B3 is connected with the negative end of the LED lamp string and the drain electrode of the switch tube M; the end B4 is connected with the grid electrode of the switching tube M; and the end B5 is connected with the sampling resistor and the source electrode of the switching tube, and the other end of the sampling resistor is grounded.
The rectifier circuit 10 converts alternating current into half-wave direct current VB1, and the control circuit 20 controls input current IB2 of the positive end of the LED string and the positive end of the capacitor C by detecting voltage VB3 of the negative end of the LED string, so that the stored energy in the capacitor C is used for ensuring sufficient current in the LED string when the capacitor C discharges.
By the circuit structure, when the voltage VB3 at the negative end of the LED lamp string is smaller than a set value, the input current IB2 is increased; when the voltage VB3 at the negative end of the LED string is greater than the set value, the input current IB2 is reduced. The control circuit 20 detects the voltage VB5 at one end of the sampling resistor R to control the voltage at the end B4, that is, the conduction of the switch tube M, so as to keep the current flowing through the LED string constant.
Specifically, the control circuit 20 detects the voltage VB3 at the negative terminal of the LED string, and when the input voltage VB1 is greater than the output voltage VB2, the terminal B2 outputs the current IB2, a part of which is used for flowing through the LED string (ILED), and a part of which is used for charging the capacitor C (IC); when the input voltage VB1 is lower than the output voltage VB2, the output current at the end B2 is 0, and the capacitor C discharges through the LED lamp string. The control circuit 20 adjusts the output current IB2 at the B2 end according to the voltage VB3, so that the stored energy in the capacitor C is used to ensure sufficient current in the LED string when the capacitor C discharges.
Preferably, the detected voltage VB3 is an average value, and the controlled input current IB2 is also an average value, so as to ensure that the energy stored in the capacitor C is sufficient in one period. Preferably, the voltage VB5 is a real-time detection value, and the conduction magnitude of the switching tube M is controlled in real time, so that the current flowing through the LED string is constant at each time.
The operation of the circuit is shown in fig. 2 and 3.
In fig. 2, ac power is converted into half-wave dc power through the rectifier circuit 10, as shown in VB 1. Since the voltage drop across the LED string is a fixed value, VB3 and VB2 are only different in DC component size but have the same waveform. The control circuit 20 controls the voltage VB2 at the output end of the B2 to be greater than or equal to the conduction voltage of the LED lamp string, the power tube M is in a conduction state, current flows through the LED lamp string, the control circuit 20 detects the voltage VB5 on the sampling resistor R, and the conduction size of the power tube M is controlled through the output voltage VB4 at the end B4, so that the current Iled in the LED lamp string is controlled to be kept unchanged, and the voltage VB5 is kept constant. The control circuit 20 controls the output current of the terminal B2 by detecting the voltage VB3 at the negative terminal of the LED string, so as to ensure that when the output current is present at the terminal B2, there is enough energy stored in the capacitor C (ILED × t — C × V), so that when the current IB2 at the terminal B2 is zero, the energy stored in the capacitor C can provide enough energy to maintain the current ILED unchanged, and no strobe (strobe is 0) is achieved. Because the current in the LED lamp string is kept constant, the change of the output current at the end B2 corresponds to the change of the charging current of the capacitor C, and the output current at the end B2 is increased, so that the charging current of the capacitor C is increased; and vice versa, and then decrease simultaneously (note: the waveform of IB2 in fig. 2 is a square wave, but not limited thereto, and the waveform when there is current may be an arbitrary waveform).
In fig. 3, when the voltage VB1 at the input end of B1 increases (from solid line to dashed line), VB1 increases accordingly, VB2, VB3 and IB2 adjust due to the feedback mechanism, the average voltage (current) is unchanged, IB2 amplitude decreases but the duty ratio is increased, and the system negative feedback keeps the capacitive energy storage (average voltage) unchanged. The control circuit 20 correspondingly reduces the output current IB2 at the end B2 according to the change of the voltage VB3, reduces the charging current on the capacitor C, reduces the stored energy and lowers the voltage VB 2; on the contrary, when the voltage VB1 at the input end of the B1 is reduced, the voltage VB2 at the end of the B2 is correspondingly reduced, the voltage VB3 is also reduced, the control circuit 20 correspondingly increases the output current IB2 at the end of the B2 according to the change of the voltage VB3, the charging current on the capacitor C is increased, the stored energy is increased, and the voltage VB2 is increased.
In a further embodiment, the structure of the control circuit 20 is shown in fig. 4, and includes a voltage control current circuit 22 and a current control circuit 21, where the current control circuit 21 is configured to control the magnitude of the output voltage VB4 at the B4 terminal according to the magnitude of the voltage VB5 at the B5 terminal; the voltage control current circuit 22 is used for controlling the output current IB2 at the terminal B2 according to the magnitude of the voltage VB3 at the terminal B3.
In a further embodiment, the structure of the voltage-controlled current circuit 22 is shown in fig. 5, and includes a voltage feedback circuit 221, a logic control circuit 222, and a charging current control circuit 223, where the voltage feedback circuit 221 is configured to output a voltage feedback signal B7 according to a voltage VB3 at B3, the logic control circuit 222 outputs a current control signal B8 according to the voltage feedback signal B7, and the charging current control circuit 223 outputs a current IB2 according to the current control signal B8 when the voltage at B1 is greater than or equal to the voltage at B2, and outputs no current when the voltage at B1 is less than the voltage at B2.
The working process is shown in figure 6:
the voltage feedback circuit 221 detects the magnitude of the voltage VB3 at the B3 end, and is used for providing an average value of the voltage VB3, comparing the voltage VB3 with the set voltage VB3A, when the voltage VB3 is greater than or equal to the voltage VB3A, the voltage feedback circuit 221 is internally discharged, when the voltage VB3 is smaller than the voltage VB3A, the voltage feedback circuit 221 is internally charged, as shown by a solid line VB3 in the figure, and a corresponding voltage feedback signal is shown by a solid line B7 in the figure. When the voltage VB3 changes, as shown by the dotted line in the figure, the discharge time of the voltage feedback signal B7 in one cycle increases and the charge time decreases, (B7 is placed in different coordinates to show that the two charge and discharge time points are different, and the magnitude comparison is not performed). Correspondingly, when the voltage VB3 changes, the logic control circuit 222 outputs a corresponding decrease in the current control signal B8 and a corresponding decrease in the current IB2 of the charging current control circuit 223 in response to the change in the voltage feedback signal B7.
Preferably, the current IB2 is K × B8, and the current IB2 is set to be K times the current control signal B8.
In a further embodiment, the voltage feedback circuit 221 is shown in fig. 7, wherein the comparator P1 is configured to compare the voltage VB3 at the negative terminal of the LED string with the first reference voltage Vref1 to obtain a comparison signal F1, and the comparison signal F1 determines whether the power transistor M1 is turned on to charge the capacitor C2 or the power transistor M2 is turned on to discharge the capacitor C2; when VB3 is larger than Vref1, the capacitor is discharged to reduce B7, when VB3 is smaller than Vref1, the capacitor is charged, B7 is improved, and by reasonably setting the values of bias1, bias2 and capacitor C2, B7 can reflect the average value of VB3 in a plurality of periods (a method for taking the average voltage of VB3 is not the only method).
In a further embodiment, the logic control circuit 222 includes a voltage-to-current conversion circuit for converting the B7 voltage signal to the current control signal B8. The magnitude of the current control signal B8 is inversely proportional to the magnitude of the voltage VB3, and when the voltage VB3 increases, B8 decreases; when the voltage VB3 decreases, B8 increases.
In a further embodiment, the charging current control circuit 223, as shown in fig. 8, includes an amplifier for amplifying the current control signal B8 by K times, and when the voltage at the terminal B1 is greater than the voltage at the terminal B2, the terminal B2 has a current output; when the voltage at the terminal B1 is increased (in the application, the voltage change in one period is represented by rising and falling, and the voltage change in the whole period is represented by increasing and decreasing), the size of IB2 is reduced, and otherwise, the size of IB2 is increased.
In a further embodiment, the current control circuit 21 is shown in fig. 9 and includes a comparator for comparing the voltage VB5 at the terminal of the sampling resistor R with the reference voltage Vref2, and when the voltage VB5 is greater than Vref2, the current in the sampling resistor R is decreased, and when the voltage VB5 is less than Vref2, the current in the sampling resistor R is increased to keep the current in the LED string constant.
In summary, the invention provides a stroboflash-free LED driving circuit, which controls and controls the current of an LED light string to be constant through a switching tube M; the input current is adjusted through the feedback of the voltage at the negative end of the LED lamp string, and the capacitor C in each period is ensured to have enough energy storage to maintain the constant current of the LED lamp string. It can eliminate stroboflash, satisfy the market to the requirement of LED illumination.
The above-described embodiments are merely illustrative of the principles of the present disclosure. It is to be understood that modifications and variations of the arrangements and details described herein will be apparent to those skilled in the art. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto, and not by the specific details presented by way of the description and illustration of the embodiments presented herein.
Claims (6)
1. A non-stroboscopic LED drive circuit is characterized by comprising a rectification circuit (10), a control circuit (20), a capacitor C, a sampling resistor R1 and a switching tube M; wherein the content of the first and second substances,
the rectifying circuit (10) is connected with an external alternating current power supply and is connected with the control circuit (20) for supplying power; the control circuit (20) is also connected with the two ends of the LED lamp string, the switch tube M and the positive end of the sampling resistor for sampling and driving control; one end of the capacitor C is connected with the positive end of the LED lamp string and the control circuit (20), and the other end of the capacitor C is grounded for storing and supplying energy.
2. The LED driving circuit according to claim 1, wherein the control circuit (20) comprises five terminals, namely a terminal B1, a terminal B2, a terminal B3, a terminal B4 and a terminal B5; the input end of the rectifying circuit (10) is connected with an external alternating current power supply, and the output end of the rectifying circuit is connected with the end B1 for power supply; the end B2 is connected with the positive end of the LED lamp string and the positive end of the capacitor C, and the negative end of the capacitor is grounded; the end B3 is connected with the negative end of the LED lamp string and the drain electrode of the switch tube M; the end B4 is connected with the grid electrode of the switching tube M; and the end B5 is connected with the sampling resistor and the source electrode of the switching tube, and the other end of the sampling resistor is grounded.
3. The LED driving circuit according to claim 2, wherein the control circuit (20) comprises a voltage-controlled current circuit (22) and a current control circuit (21), wherein the current control circuit (21) is provided with a terminal B4 and a terminal B5, and the voltage-controlled current circuit (22) is provided with a terminal B1, a terminal B2 and a terminal B3.
4. The LED driving circuit according to claim 3, wherein the voltage controlled current circuit (22) comprises a voltage feedback circuit (221), a logic control circuit (222), a charging current control circuit (223); the voltage feedback circuit (221) is provided with a terminal B3, the voltage feedback circuit outputs a voltage feedback signal to the logic control circuit (222) according to the voltage of the terminal B3, and the logic control circuit (222) outputs a current control signal to the charging current control circuit (223) according to the voltage feedback signal; the charging current control circuit (223) is provided with a terminal B1 and a terminal B2.
5. The LED driving circuit according to claim 4, wherein the voltage feedback circuit (221) comprises a power tube M1, a power tube M2, a comparator P1 and a capacitor C2, wherein the gates and the drains of the power tube M1 and the power tube M2 are interconnected; two comparison ends of a comparator P1 are respectively connected with a voltage VB3 and a first reference voltage Vref1 which obtain a B3 end, an output end is connected with gates of a power tube M1 and a power tube M2, a source electrode of the power tube M1 is connected with a bias end bias1, and a source electrode of the power tube M2 is connected with a bias end bias 2; the drains of the power tube M1 and the power tube M2 are connected with the capacitor C2 and output voltage feedback signals.
6. The LED driving circuit according to claim 4 or 5, wherein the logic control circuit (222) comprises a voltage-to-current conversion circuit for converting a voltage feedback signal to a current control signal; the charging current control circuit (223) comprises an amplifier for amplifying a current control signal; the current control circuit (21) comprises a comparator for comparing the voltage of the sampling resistor with a reference voltage Vref 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822133173.7U CN210405708U (en) | 2018-12-18 | 2018-12-18 | Linear LED drive circuit for adjusting power and current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201822133173.7U CN210405708U (en) | 2018-12-18 | 2018-12-18 | Linear LED drive circuit for adjusting power and current |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210405708U true CN210405708U (en) | 2020-04-24 |
Family
ID=70337673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201822133173.7U Active CN210405708U (en) | 2018-12-18 | 2018-12-18 | Linear LED drive circuit for adjusting power and current |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210405708U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109600880A (en) * | 2018-12-18 | 2019-04-09 | 陕西亚成微电子股份有限公司 | A kind of no stroboscopic LED driving method and circuit |
-
2018
- 2018-12-18 CN CN201822133173.7U patent/CN210405708U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109600880A (en) * | 2018-12-18 | 2019-04-09 | 陕西亚成微电子股份有限公司 | A kind of no stroboscopic LED driving method and circuit |
| CN109600880B (en) * | 2018-12-18 | 2024-03-26 | 陕西亚成微电子股份有限公司 | Stroboscopic-free LED driving method and circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10531528B2 (en) | LED drive circuit with a programmable input for LED lighting | |
| CN102202449B (en) | LED driving control circuit and method | |
| CN103648202B (en) | Active power factor correction control circuit, chip and LED (Light Emitting Diode) drive circuit | |
| CN113099579B (en) | LED constant current driving system and method | |
| US10716184B1 (en) | LED tube | |
| CN109348587B (en) | LED constant current drive circuit with high PF does not have stroboscopic | |
| US9357602B1 (en) | LED dimming and driving method and circuit using the same | |
| CN112532083B (en) | Switching power supply constant current output control system in continuous conduction mode | |
| CN101868078A (en) | Single-power level LED constant current driving device with high power factor | |
| CN110035580B (en) | Constant-current control circuit of boosting type LED drive circuit and application thereof | |
| WO2018133263A1 (en) | Led driving circuit and driving method thereof | |
| CN210405708U (en) | Linear LED drive circuit for adjusting power and current | |
| CN111511074B (en) | LED driving circuit and control method | |
| CN111182684B (en) | Non-stroboscopic LED drive circuit compatible with silicon controlled rectifier dimmer | |
| TWI448191B (en) | Feedback control to reduce power consumption light-emitting diode driving device | |
| CN210183607U (en) | Stroboflash-free high-power-factor LED driving circuit | |
| CN109618463B (en) | LED driving power supply dimming method without electrolytic capacitor | |
| US20200375003A1 (en) | Linear constant-current led drive circuit adaptive to wide voltage range | |
| CN109600880B (en) | Stroboscopic-free LED driving method and circuit | |
| CN109587880B (en) | Driving method and circuit for silicon controlled rectifier dimming LED | |
| CN111885781B (en) | Linear LED intelligent dimming driving power supply and control method thereof | |
| CN209882155U (en) | Silicon controlled rectifier LED drive circuit of adjusting luminance | |
| CN109831844B (en) | Stroboflash-free high-power-factor LED driving method and circuit | |
| CN210725411U (en) | LED drive circuit | |
| KR102207025B1 (en) | Dimming LED circuit enhancement DC/DC controller integrated circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220721 Address after: 710000 Room 201, building 6, No. 15, Shanglinyuan 1st Road, high tech Zone, Xi'an, Shaanxi Province Patentee after: XI'AN YARUN MICRO OPTOELECTRONICS TECHNOLOGY CO.,LTD. Address before: Room 301, block a, Hanyun Pavilion, Xi'an Software Park, No.68, Keji 2nd Road, high tech Zone, Xi'an City, Shaanxi Province, 710075 Patentee before: SHAANXI REACTOR MICROELECTRONICS Co.,Ltd. |
|
| TR01 | Transfer of patent right |