CN201839477U - LED drive circuit and lamp - Google Patents
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Abstract
The utility model discloses a LED drive circuit and lamps and lanterns with function of adjusting luminance contains TRIAC light modulator, and it receives alternating current input voltage, generates phase-cut voltage signal, and after rectifier module rectification, the coupling is to the signal generator that adjusts luminance again, and power factor correction controller receives the output signal of the signal generator that adjusts luminance and reflects the feedback signal of LED luminance, and the closure of output switch control signal control switch pipe is with turn-off to the realization is to LED's drive. The LED is dimmed by adjusting the conduction angle of the TRIAC dimmer.
Description
Technical Field
The embodiment of the utility model relates to a LED drive circuit especially relates to the drive circuit who utilizes TRIAC (TRIAC) to adjust luminance to LED. The embodiment of the utility model also relates to the lamps and lanterns that use this drive circuit.
Background
TRIACs (TRIACs) are common rectifying devices in the power electronics field, which can be switched on in both directions by a control signal at a gate. When the TRIAC is turned on, the gate control signal is disabled, and when the current through the TRIAC is lower than the holding current, the TRIAC is turned off from on.
The dimmer based on the TRIAC is widely applied to dimming of pure resistive loads such as incandescent lamps, halogen lamps and the like at present, and the basic principle is that the conduction angle of the TRIAC is controlled by controlling the trigger time of the TRIAC, so that the voltage of a light source (load) is adjusted, and the aim of dimming is fulfilled.
Because of the advantages of small size, energy saving, long service life, etc., Light Emitting Diodes (LEDs) are one of the most potential alternative Light sources of traditional Light sources (such as incandescent lamps). The current common dimming technologies of the LED include PWM dimming, which is based on the principle of controlling the on-time of the current flowing through the LED, and analog dimming, which is based on the principle of directly controlling the magnitude of the current flowing through the LED. When a TRIAC dimming scheme is used, the current through the TRIAC is not controllable due to LC resonance in the circuit, since the LED driver is not a purely resistive load, so that dimming cannot be performed efficiently. The prior art has addressed this problem by adding dummy loads (dummy loads), but reduces efficiency due to the power consumption of the dummy loads.
There is therefore a need to improve the TRIAC dimming scheme of existing LEDs to reduce power consumption and improve efficiency.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a can carry out the drive circuit who adjusts luminance to LED to solve current TRIAC dimmer and can not directly be applied to LED drive circuit in order to realize the problem of adjusting luminance to LED.
In an aspect of the present invention, a driving circuit for dimming a LED is provided, including: a TRIAC (TRIAC) dimmer having an input coupled to an AC input voltage and an output from which a phase-cut voltage is output; a rectifying circuit having an input coupled to an output of the triac dimmer and an output from which a dc signal is output; a filter circuit having an input coupled to the output of the rectifier circuit and an output, the filtered signal coupled from the output of the filter circuit to an energy transfer element; the voltage division circuit is coupled with the output end of the rectification circuit and outputs a voltage division signal from the output end of the voltage division circuit; the input end of the dimming signal generator is coupled with the output end of the voltage division circuit; a Power Factor Correction (PFC) controller for receiving the output signal of the dimming signal generator and the signal reflecting the LED brightness and outputting a driving signal from an output end; and the input end of the driver is coupled with the output end of the power factor correction controller, and a switch control signal is output from the output end to control the switch tube, so that the filtered signal is coupled to the LED.
Preferably, the power factor correction controller is an active power factor correction circuit.
Preferably, the pfc controller operates in a critical conduction mode.
Preferably, the pfc controller operates in a continuous conduction mode.
Preferably, the pfc controller operates in discontinuous conduction mode.
Preferably, the energy transfer element is a transformer.
Preferably, the energy transfer element is an inductor.
Preferably, the driving circuit is based on any one of a forward topology, a FLYBACK (fly black) topology, a HALF-BRIDGE (HALF-BRIDGE) topology, and a push-pull topology.
Preferably, the driving circuit is based on any one of a BUCK (BUCK) topology, a BOOST (BOOST) topology, a BUCK-BOOST (BUCK-BOOST) topology, a single-ended primary inductive converter (SEPIC) topology.
Preferably, the signal reflecting the brightness of the LED is from the primary side of the transformer.
Preferably, the driving circuit further includes: and one input end of the equivalent load average current calculation module is coupled to one of the output end of the PFC controller, the output end of the driver and the output end of the auxiliary winding, the other input end of the equivalent load average current calculation module is coupled to a sampling signal reflecting the primary side current value of the transformer, and the output end of the equivalent load average current calculation module generates the signal reflecting the LED brightness and is coupled to the PFC controller.
Preferably, the equivalent load average current calculation module includes: a first switch, one end of which is coupled to a signal reflecting the primary side current; a capacitor coupled between the other end of the first switch and ground; a second switch, one end of which is coupled to the connection point of the first switch and the capacitor; a third switch coupled between the other end of the second switch and ground; the connection point between the second switch and the third switch outputs a signal reflecting the brightness of the LED; the first switch (S1), the second switch (S2), and the third switch (S3) are controlled by one of an output signal of the PFC controller, an output signal of the driver, and an auxiliary winding output signal.
Preferably, the dimming signal generator outputs a pulse width modulation signal or an amplitude-controlled signal according to the rectified phase-cut voltage.
Preferably, the power factor correction controller includes: the non-inverting end of the error amplifier is coupled with the output of the dimming signal generator, and the inverting end of the error amplifier is coupled with a signal reflecting the LED brightness; a multiplier for multiplying the output signal of the error amplifier and the signal reflecting the DC signal to output a reference signal; the comparator is used for receiving the reference signal at an inverting terminal and coupling a non-inverting terminal with a voltage signal reflecting the current flowing through the energy transmission element; the current zero-crossing detector is coupled to the energy transmission element and used for detecting the energy transmission condition of the energy transmission element; the output signal of the comparator is coupled to the reset end of the trigger, the set end of the trigger is coupled to the output end of the current zero-crossing detector and receives the output signal of the current zero-crossing detector, and the output end of the trigger is coupled to the driver.
Preferably, the power factor correction controller includes: the non-inverting end of the error amplifier is coupled with the output of the dimming signal generator, and the inverting end of the error amplifier is coupled with a signal reflecting the LED brightness; a current zero crossing detector coupled to the energy transfer element for detecting an energy transfer condition of the energy transfer element; the switching-on time length controller receives an output signal of the error amplifier and an output signal of the current zero-crossing detector, the output signal of the switching-on time length controller is coupled to a reset end of the trigger, a set end of the trigger is coupled with an output end of the current zero-crossing detector, the output signal of the current zero-crossing detector is received, and an output end of the trigger is coupled with the driver.
In another aspect of the present invention, a lamp is provided, which includes the above-mentioned driving circuit.
The driving circuit and the lamp using the driving circuit solve the problem that a TRIAC dimmer in the prior art cannot directly dim LEDs, and are compatible with the dimming scheme of the conventional light source (such as an incandescent lamp).
Drawings
Fig. 1 illustrates a prior art solution for dimming an LED by using a TRIAC dimmer.
Fig. 2 shows a specific embodiment of a secondary sampling and based on a PFC with multiplier according to an embodiment of the present invention.
Fig. 3 is a waveform of a correlation signal in one half period of the AC input voltage AC in the embodiment of fig. 2.
Fig. 4 is a specific embodiment of a secondary side sampling and on-band-based time length control circuit PFC according to the embodiment of the present invention.
Fig. 5 is a specific embodiment of a primary side sampling and based on a PFC with a multiplier, according to an embodiment of the present invention.
Fig. 6 is a detailed block diagram of the equivalent load average current calculation module 570 shown in fig. 5.
Fig. 7 is a specific embodiment of a primary side sampling and band on time length control circuit PFC according to the embodiment of the present invention.
Detailed Description
In the following detailed description and in the drawings, like reference numerals refer to like parts, unless otherwise specified.
Fig. 1 is a schematic diagram of a conventional LED TRIAC (TRIAC) dimming scheme. The dimming principle thereof is explained below. An alternating input voltage Vin enters a TRIAC dimmer from an input end, after the action of the TRIAC dimmer, a voltage signal 101 with controlled conduction time is output from an output end, the voltage signal is input into a rectification module from the input end, a unidirectional voltage 102 is obtained from the output end of the rectification module, the voltage 102 is divided by a voltage dividing circuit, a voltage 103 is obtained from the output end of the voltage dividing circuit and is transmitted to the input end of a dimming signal generator, and a pulse signal (PWM signal) 104 with the width being adjusted is obtained from the output end of the dimming signal generator. By adjusting the on-time of the TRIAC dimmer, the waveform of the input voltage 103 of the dimming signal generator is changed, and accordingly, the pulse width of the output signal 104 of the dimming signal generator is adjusted, and then the energy transmitted to the load LED through the transformer TR is adjusted under the action of a Non-power factor correction (Non-PFC) controller, so that the brightness of the LED is finally controlled.
The existence of the dummy load Rd in fig. 1 can solve the problem that the current Itr flowing through the TRIAC dimmer is uncontrollable due to LC resonance in the circuit, and thus the TRIAC dimmer cannot dim because the turn-off time is uncontrollable. On the other hand, however, the introduction of the dummy load Rd generates additional power consumption, which becomes more prominent today with increasing emphasis on the efficiency of LED driving circuits.
Fig. 2 is a schematic diagram of a driving circuit according to an embodiment of the present invention, the driving circuit of this embodiment is based on a FLYBACK (fly black) topology, a feedback signal is sampled from a secondary side of a transformer, and the sampled signal is a signal representing LED brightness, such as a voltage signal or a current signal. This embodiment is improved over the prior art shown in fig. 1 by using a controller having a Power Factor Correction (PFC) function, and eliminating the dummy load Rd. In this embodiment, the PFC controller 250 may operate in a critical conduction mode (critical conduction mode).
Fig. 3 is a waveform of a relevant signal in the driving circuit of the embodiment shown in fig. 2 during a half duty cycle of the ac input voltage Vin. Fig. 3a shows a waveform of the ac input voltage Vin in fig. 2, the ac input voltage Vin is input to an input terminal of the TRIAC dimmer, a phase-cut voltage 201 is obtained from an output terminal of the TRIAC dimmer, the phase-cut voltage is input to an input terminal of the rectifier module, and a dc voltage 202 is obtained at the output terminal after the input voltage is rectified by the rectifier module, and the waveform is shown as 3b in fig. 3.β 1 represents a conduction angle of the TRIAC dimmer corresponding to the dc voltage waveform, and the conduction angle can be controlled by controlling the TRIAC dimmer.
The dc voltage 202 is coupled to the transformer via the filter circuit 220, and is divided by the voltage divider circuit to obtain a voltage 203 at the output of the voltage divider circuit, the waveform of which is shown in fig. 3 c. In this embodiment, the filter circuit includes a capacitor C1. The voltage 203 is coupled to an input of the dimming signal generator 230, and the dimming signal generator 230 outputs a parameter-controlled signal, such as a duty-cycle-controlled or amplitude-controlled signal, at an output according to the input voltage 203. The signal filtered by the filter circuit 220 is coupled to the LED via a transformer.
In the present embodiment, the dimming signal generator 230 includes a comparator 231 having a non-inverting terminal coupled to the voltage 203 and an inverting terminal coupled to the signal 204, and the dimming signal generator 230 outputs a signal 205 coupled to the PFC controller module 250. In this embodiment, the signal 204 is 0V, and when the voltage 203 is higher than 0V, the output signal 205 is at a high level, and when the value of the voltage 203 is lower than 0V, the output signal 205 is at a low level. The signal 205 has a waveform as shown at 3d in fig. 3.
When the switch Sw is closed, the primary current Ip of the transformer TR continuously increases, when the current increases until the voltage signal 209 reaches the reference level value of the inverting terminal of the comparator 253, the output signal 210 of the comparator 253 becomes high level, the trigger 255 is reset, the output signal 212 becomes low level, the switch tube Sw is turned off, then energy is output to the load LED through the secondary winding Ls of the transformer, the secondary current Id gradually decreases, and when the secondary current Id decreases to 0, the information is obtained by detecting the output signal 213 of the third winding Lt of the transformer through the current zero-crossing detector 254. The current zero crossing detector 254 outputs a signal 211 that causes the flip-flop 255 to be set, the flip-flop output signal 212 goes high, and the switching tube Sw is closed again.
Fig. 3e shows the waveform of the relevant signal when Rp =1 Ω, and the waveform of the peak envelope of the current Ip is the waveform of the signal 208. It should be noted that 3e in fig. 3 only schematically shows several waveforms of the current Ip. In this embodiment, the controller 250 operates in the critical conduction mode, and the primary current Ip increases immediately after the secondary current decreases to 0 until the signal 209 rises to the reference level. For clarity of illustration, the current signal present between the two current waveforms in the figure is not shown.
Since the multiplier output signal 208 as a reference signal is similar in waveform to the multiplier input signal 203, the peak envelope of the current Ip is also similar in waveform to the voltage 203. The current Ip is filtered by the capacitor C1, and the waveform of the input current Itr is shown as 3e in fig. 3. The waveform of the input current Itr is in phase and similar to that of the phase-cut voltage 201 of the alternating-current input voltage AC after passing through the TRIAC dimmer, so that the TRIAC dimmer can be prevented from being turned off by mistake without adding a dummy load, and in addition, the power factor of the system is also improved.
The principle of dimming an LED by a TRIAC dimmer is explained in connection with fig. 3.
Taking a half cycle of the input ac voltage Vin as an example, the TRIAC dimmer is adjusted such that the dimmer conduction time is adjusted from T1 to T2, and accordingly, the TRIAC dimmer conduction angle is adjusted from β 1 to β 2. Thus, the conduction angle corresponding to the on-duration of the voltage 203 is adjusted from β 1 to β 2, and the conduction angle corresponding to the high-level duration of the output signal 205 of the dimming signal generator is adjusted from β 1 to β 2. The waveform of the output signal 208 in both cases is shown as 3e in fig. 3. Compared with the conduction angle beta 1, the energy transferred to the load is reduced when the conduction angle is beta 2, thereby achieving the purpose of dimming.
The feedback signal 206 is generated by sampling a voltage or current signal related to the brightness of the self-presenting load LED and acting through the feedback network 270. The feedback signal 206 is coupled to the PFC controller 250, which acts to stabilize the LED brightness. In this embodiment, if the LED brightness suddenly increases, the feedback signal 206 representing the brightness increases, the output 207 of the operational amplifier 251 decreases, the output 208 of the multiplier decreases, the peak value of the current Ip decreases, the energy transmitted to the LED decreases, and the LED brightness decreases.
Fig. 4 is a schematic diagram of a driving circuit according to another embodiment of the present invention. The driving circuit of this embodiment differs from the embodiment shown in fig. 2 in that the PFC controller 450 does not employ a multiplier but employs an on-time controller (on-time controller).
Under the condition that the waveform of the ac input voltage Vin, the conduction angle of the TRIAC dimmer, and the amplitude of the feedback signal 206 are all constant, the output signal 207 of the operational amplifier 251 is a fixed value. When the current zero-crossing detector 254 detects that the secondary current Id decreases to zero, the output signal 211 sets the RS flip-flop 255, and controls the switching tube Sw to close. Under the action of the signal 211 and the output signal 207 of the operational amplifier 251, the on-time controller 453 outputs a reset signal 410 to the RS flip-flop after a corresponding time period, and outputs a signal 412 to turn off the switch.
Referring to fig. 3b, a half-cycle waveform of a 50Hz mains ac input voltage Vin is taken as an example. The frequency of the voltage 202 is 100HZ, and the operating frequency of the switching tube is high frequency (several tens of KHZ to several MHZ), and in the case that the operating frequency of the switching tube is much higher than the frequency of the voltage 202, assuming that the switching tube is turned on at time T3, the peak value Ipk of the primary current Ip is expressed as:
Wherein, VT3At time T3, voltage 202 is set to Ton, which is the conduction duration of the switch tube corresponding to conduction duration controller 453. In the case where the output signal 207 is a fixed value, the duration of Ton is constant, and the peak value of the current Ip and VT3And proportionally, the envelope of the peak current Ip is similar to the voltage 202 waveform throughout the half cycle waveform. After filtering by the capacitor C1, the waveform of the input current Itr is similar to the waveform of the voltage 201, so that the control of the waveform of the input current Itr is achieved.
By controlling the dimming angle of the TRIAC dimmer, the duty ratio of the output signal 205 of the dimming signal generator 230 is changed, and the output signal 207 of the operational amplifier 251 controls the conduction time of the conduction time controller 453, wherein the conduction time is the conduction time of the switching tube Sw in one switching period, so that the peak value of the primary side current Ip of the transformer is controlled, that is, the energy transmitted to the load LED through the transformer is controlled, and the dimming of the LED is realized.
Fig. 5 is a driving circuit according to another embodiment of the present invention. The drive circuit of this embodiment differs from the embodiment shown in fig. 2 in that primary side control is employed. The voltage signal 209 representing the information of the primary current of the transformer TR is fed to the PFC controller 250 and also to the equivalent load average current calculation module 570, and the other input of the module 570 is the output signal 212 from the PFC controller 250, and the output signal 506 is coupled to the PFC controller 250.
Fig. 6 is a schematic block diagram of the equivalent load average current calculation module 570 shown in fig. 5, which includes: a first switch S1, one end of which is coupled to the voltage signal 209 via LEB (leading edge blanking circuit), and the other end of which is coupled to the connection point of the second switch S2 and the capacitor C2; a capacitor C2 coupled between one end of the first switch S1 and ground; a second switch S2, having one end coupled to the connection point of the first switch S1 and the capacitor C2 and the other end coupled to the third switch S3; the third switch S3 is coupled between one end of the second switch S2 and ground. The signal 212 simultaneously controls the first switch S1, the second switch S2, and the third switch S3, and the junction between the second switch S2 and the third switch S3 outputs the signal 506.
When the signal 212 is high, i.e. the switch SW is on, the second switch S2 is turned off; the first switch S1 is closed and the capacitor C2 is charged; third switch S3 is closed to ground and the value of signal 506 remains zero. When the primary current reaches the peak value Ipk, the voltage across the capacitor C2 should reach a maximum value Ipk × Rp. Thereafter, the signal 212 goes low, the switch SW is turned off, the first switch S1 and the third switch S3 are turned off, and the second switch S2 is closed, so that the voltage across the capacitor C2 is coupled out. This state is maintained until the switching tube SW is turned on again in the next period.
Setting the on-time of the switching tube SW as Ton, the off-time as Toff, the turn ratio of the primary and secondary windings of the transformer as N, and the average value Ieq of the signal 506 and the average value Io of the load current can be respectively expressed as:
Wherein,
is the average value of the secondary current Id. From the two formulae, obtain
Equation (4)
Equation (3) shows that the average Ieq of the signal 506 is proportional to the load current average Io, i.e. the signal 506 can reflect the load condition, and the monitoring of the load condition is achieved by sampling the primary side information.
In another embodiment, the signals for controlling the first switch S1, the second switch S2, and the third switch S3 may also be derived from other signals indicating the state of the switch tube SW, such as the output signal of the driver or the output signal 213 of the third winding Lt.
Fig. 7 is a driving circuit according to another embodiment of the present invention. The driving circuit of this embodiment is different from the driving circuit of the embodiment shown in fig. 4 in that primary side control is adopted, and the implementation principle of the PFC controller 450 is the same as that of the embodiment shown in fig. 4, and is not repeated here; the difference of the driving circuit with respect to the embodiment shown in fig. 5 is that the PFC controller 450 does not use a multiplier, but uses an on-time controller (on-time controller), and the implementation principle of the primary side control is the same as that of the embodiment shown in fig. 5, and is not repeated here.
It should be noted that the embodiments described are to be considered as illustrative and not restrictive. Numerous alternatives may be devised by those skilled in the art without departing from the scope of the invention. For example, although the embodiments are all based on flyback topologies, the present invention is equally applicable to other topologies in switching power supplies, such as BUCK-type (BUCK), BOOST-type (BOOST), BUCK-BOOST-type (BUCK-BOOST), single-ended primary inductive converter (SEPIC) type, forward-type, full-bridge type, half-bridge type, push-pull type, etc. For another example, although the PFC controller in the above-mentioned embodiment is in the critical Conduction Mode, the present invention is also applicable to the Discontinuous Conduction Mode (Discontinuous Conduction Mode) or the Continuous Conduction Mode (Continuous Conduction Mode). The signal types or signal specific values given in the embodiments may be present in other types or other specific values in other embodiments. As another example, in other embodiments according to the present invention, the filter circuit 220 may also include an inductive element or a combination of a capacitive element and an inductive element. The dimming signal generator may further comprise an RC circuit module to obtain the parameter with the controlled output amplitude. In addition, the LED driving circuit described above may be implemented as an independent device, or may be implemented in a lamp.
The foregoing relates to preferred embodiments or examples only, and numerous modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims and are not to be construed as limiting the scope of the invention. The specific embodiments described herein are merely illustrative and various modifications and equivalents may occur to those skilled in the art, which fall within the spirit and scope of the present invention. The protection scope covered by the utility model is subject to the appended claims. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of the claims and equivalents thereof.
Claims (14)
1. An LED driver circuit comprising:
a triac dimmer having an input coupled to an ac input voltage and an output from which a phase-cut voltage is output;
a rectifying circuit having an input coupled to an output of the triac dimmer and an output from which a dc signal is output;
a filter circuit having an input coupled to the output of the rectifier circuit and an output, the filtered signal coupled from the output of the filter circuit to an energy transfer element;
the voltage division circuit is coupled with the output end of the rectification circuit and outputs a voltage division signal from the output end of the voltage division circuit;
the input end of the dimming signal generator is coupled with the output end of the voltage division circuit;
characterized in that, the LED drive circuit further comprises:
the power factor correction controller receives the output signal of the dimming signal generator and the signal reflecting the LED brightness and outputs a driving signal from an output end;
and the input end of the driver is coupled with the output end of the power factor correction controller, and a switch control signal is output from the output end to control the switch tube, so that the filtered signal is coupled to the LED.
2. The driver circuit of claim 1, wherein the power factor correction controller is an active power factor correction circuit.
3. The driving circuit according to claim 1 or 2, wherein the pfc controller operates in one of a critical conduction mode, a continuous conduction mode, and an intermittent conduction mode.
4. The drive circuit of claim 1, wherein the energy transfer element is a transformer.
5. The drive circuit of claim 1, wherein the energy transfer element is an inductor.
6. A driver circuit according to claim 1 or 4, wherein the driver circuit is based on any one of a forward topology, a flyback topology, a half-bridge topology, a push-pull topology.
7. The driver circuit of claim 1 or 5, wherein the driver circuit is based on any one of a buck topology, a boost topology, a buck-boost topology, a single-ended primary inductor converter topology.
8. The driving circuit of claim 6, wherein the signal reflecting the brightness of the LED is from a primary side of a transformer.
9. The drive circuit of claim 8, wherein the drive circuit further comprises: and one input end of the equivalent load average current calculation module is coupled to one of the output end of the PFC controller, the output end of the driver and the output end of the auxiliary winding, the other input end of the equivalent load average current calculation module is coupled to a sampling signal reflecting the primary side current value of the transformer, and the output end of the equivalent load average current calculation module generates the signal reflecting the LED brightness and is coupled to the PFC controller.
10. The driving circuit of claim 9, wherein the equivalent load average current calculation module comprises:
a first switch, one end of which is coupled to a signal reflecting the primary side current;
a capacitor coupled between the other end of the first switch and ground;
a second switch, one end of which is coupled to the connection point of the first switch and the capacitor;
a third switch coupled between the other end of the second switch and ground;
the connection point between the second switch and the third switch outputs a signal reflecting the brightness of the LED;
the first switch, the second switch and the third switch are controlled by one of an output signal of the PFC controller, an output signal of the driver and an output signal of the auxiliary winding.
11. The driving circuit of claim 1, wherein the dimming signal generator outputs a pulse width modulation signal or an amplitude controlled signal according to the rectified phase cut voltage.
12. The drive circuit according to claim 1, wherein the power factor correction controller comprises:
the non-inverting end of the error amplifier is coupled with the output of the dimming signal generator, and the inverting end of the error amplifier is coupled with a signal reflecting the LED brightness;
a multiplier for multiplying the output signal of the error amplifier and the signal reflecting the DC signal to output a reference signal;
the comparator is used for receiving the reference signal at an inverting terminal and coupling a non-inverting terminal with a voltage signal reflecting the current flowing through the energy transmission element;
the current zero-crossing detector is coupled to the energy transmission element and used for detecting the energy transmission condition of the energy transmission element;
the output signal of the comparator is coupled to the reset end of the trigger, the set end of the trigger is coupled to the output end of the current zero-crossing detector and receives the output signal of the current zero-crossing detector, and the output end of the trigger is coupled to the driver.
13. The drive circuit according to claim 1, wherein the power factor correction controller comprises:
the non-inverting end of the error amplifier is coupled with the output of the dimming signal generator, and the inverting end of the error amplifier is coupled with a signal reflecting the LED brightness;
a current zero crossing detector coupled to the energy transfer element for detecting an energy transfer condition of the energy transfer element;
a conduction time length controller receiving an output signal of the error amplifier and an output signal of the current zero-crossing detector,
and the output signal of the conduction time length controller is coupled to the reset end of the trigger, the setting end of the trigger is coupled to the output end of the current zero-crossing detector and receives the output signal of the current zero-crossing detector, and the output end of the trigger is coupled to the driver.
14. A lamp provided with the driving circuit as claimed in claim 1.
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| CN102612203A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | LED (Light-Emitting Diode) illumination driving circuit with night light function |
| CN102612202A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | Flyback framework-based switch-type light-emitting diode (LED) illumination dimming method |
| CN102638169A (en) * | 2012-05-08 | 2012-08-15 | 矽力杰半导体技术(杭州)有限公司 | Control circuit and control method of flyback convertor and alternating current-direct current power converting circuit applying control circuit of flyback convertor |
| CN102752940A (en) * | 2012-07-19 | 2012-10-24 | 矽力杰半导体技术(杭州)有限公司 | High-efficiency LED (light-emitting diode) drive circuit and drive method thereof |
| CN103329618A (en) * | 2011-06-17 | 2013-09-25 | 马维尔国际贸易有限公司 | TRIAC dimming systems for solid-state loads |
| CN103716965A (en) * | 2013-12-30 | 2014-04-09 | 成都芯源系统有限公司 | LED driving device and control circuit and output current detection circuit thereof |
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-
2010
- 2010-05-19 CN CN2010201951247U patent/CN201839477U/en not_active Expired - Fee Related
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| CN103329618B (en) * | 2011-06-17 | 2016-06-29 | 马维尔国际贸易有限公司 | TRIAC light adjusting system for solid-state load |
| CN103329618A (en) * | 2011-06-17 | 2013-09-25 | 马维尔国际贸易有限公司 | TRIAC dimming systems for solid-state loads |
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| CN102612202A (en) * | 2011-12-05 | 2012-07-25 | 北方工业大学 | Flyback framework-based switch-type light-emitting diode (LED) illumination dimming method |
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| CN104254162A (en) * | 2013-06-25 | 2014-12-31 | 华东理工大学 | An LED constant current power supply |
| CN103716965B (en) * | 2013-12-30 | 2016-04-27 | 成都芯源系统有限公司 | LED driving device and control circuit and output current detection circuit thereof |
| CN103716965A (en) * | 2013-12-30 | 2014-04-09 | 成都芯源系统有限公司 | LED driving device and control circuit and output current detection circuit thereof |
| CN104535854B (en) * | 2014-06-13 | 2017-07-14 | 成都芯源系统有限公司 | LED driving device, controller thereof and dimming mode detection method |
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| CN105282907A (en) * | 2014-07-07 | 2016-01-27 | 盛群半导体股份有限公司 | Light emitting diode backlight driving device |
| CN105282907B (en) * | 2014-07-07 | 2017-08-25 | 盛群半导体股份有限公司 | LED backlight drive device |
| CN104142420A (en) * | 2014-08-04 | 2014-11-12 | 黄钦阳 | Transformer secondary winding zero current detecting circuit used for LED driving power source |
| CN105338687A (en) * | 2014-08-09 | 2016-02-17 | 绿仕环保科技（上海）有限公司 | Intelligent switch panel for LED lamp |
| CN105338687B (en) * | 2014-08-09 | 2018-09-14 | 路晟（上海）科技有限公司 | intelligent switch panel for LED lamp |
| CN106304504A (en) * | 2016-09-30 | 2017-01-04 | 成都捷科菲友信息技术有限公司 | A kind of off-line type LED drive circuit |
| CN107071958A (en) * | 2016-12-29 | 2017-08-18 | 深圳市拓革科技有限公司 | It is a kind of can multi-mode operation primary side adjustment LED drive circuit and control method |
| CN108507561A (en) * | 2018-03-05 | 2018-09-07 | 华南理工大学 | A kind of VLC based on mobile terminal and IMU fusion and positioning methods |
| CN109587884A (en) * | 2018-12-21 | 2019-04-05 | 肖志蓝 | A kind of adjusting circuit and its working method for LED light colour temperature and brightness regulation |
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