CN109041348A

CN109041348A - Adaptive circuit module, the LED drive circuit with controllable silicon dimmer and method

Info

Publication number: CN109041348A
Application number: CN201811007069.1A
Authority: CN
Inventors: 王曙光; 杨林伟; 陈晓亮
Original assignee: Xiamen Bi Yi Microelectronics Technology Co Ltd
Current assignee: Xiamen Bi Yi Microelectronics Technology Co Ltd
Priority date: 2018-08-31
Filing date: 2018-08-31
Publication date: 2018-12-18
Anticipated expiration: 2038-08-31
Also published as: CN109041348B

Abstract

Present invention discloses a kind of adaptive circuit module, LED drive circuit and method with controllable silicon dimmer, LED drive circuit includes controllable silicon dimmer, rectification circuit, leadage circuit, constant-current control circuit, adaptive circuit module；Adaptive circuit module is separately connected rectification circuit, leadage circuit, constant-current control circuit, and rectification circuit connects controllable silicon dimmer；The leadage circuit connects constant-current control circuit, and constant-current control circuit connects LED light, and the adaptive circuit module is used to adaptively control the leakage current in leadage circuit according at least to the opening imformation of controllable silicon dimmer.The compatible all controllable silicon dimmers of the present invention, and the pulse current of different amplitudes or distinct pulse widths or different frequency can be generated according to different controllable silicon dimmers to control the unlatching of controllable silicon dimmer, to improve the not efficiency of homologous ray and compatible all controllable silicon dimmers to the maximum extent.

Description

Self-adaptive circuit module, LED driving circuit with silicon controlled rectifier dimmer and method

Technical Field

The invention belongs to the technical field of power electronics, and particularly relates to a self-adaptive circuit module, an LED driving circuit and an LED driving method thereof.

Background

The silicon controlled dimming is a commonly used dimming method at present. The silicon controlled dimmer adopts a phase control method to realize dimming, namely the silicon controlled dimmer is controlled to be conducted in each half cycle of sine wave to obtain the same conduction phase angle. By adjusting the chopping phase of the silicon controlled dimmer, the size of the conduction phase angle can be changed, and dimming is realized.

Thyristor dimmers were originally used to dim incandescent lamps, and with the popularity of LED light sources, more and more LED driving circuits have adopted thyristor dimmers as dimming means. However, the system efficiency of the existing LED driving circuit still needs to be improved, and it is difficult to be compatible with all the triac dimmers.

Referring to fig. 1, a one-way thyristor, also called a thyristor, is shown in fig. 1-a, and can be divided into three terminals of four silicon regions P, N, P, N and A, K, G. As soon as the drawing is cut into two halves as shown in fig. 1-b, it can be easily understood that a unidirectional thyristor is composed of a PNP transistor and an NPN transistor as main components as shown in fig. 1-c.

Turning on the power control circuit based on fig. 1-C as shown in fig. 2, when the positive electrode-negative electrode (a-K) is connected with the positive voltage V, the transistor Q2 will conduct in the positive direction as long as the gate G is connected with the trigger power Vg, the turn-on moment Q1 is just similar to the turn-on of a load connected with the collector of Q1 and the positive electrode of the power, and then Q1 is also conducted under the pull current of Q2, at this time, since C is charged, even if the trigger power Vg of the G pole is disconnected, Q1 and Q2 can maintain the conducting state under the interaction, and Q1 and Q2 will be cut off again only after the power voltage V becomes quite small.

Compared with a unidirectional thyristor, the bidirectional thyristor has the biggest difference in principle that bidirectional conduction can be realized, the anode and the cathode are not needed, T1 and T2 are used instead, the structural schematic diagram is shown in figure 3-a, if the difference of G level is not considered, the bidirectional thyristor is divided into figure 3-b, and the bidirectional thyristor is equivalent to the connection of two unidirectional thyristors which are reversely connected in parallel and is shown in figure 3-c.

Referring to fig. 4, fig. 4 is a schematic diagram of a triac dimmer. The turn-on of the thyristor dimmer requires a large current, but the maintenance conduction does not require a large current, and the turn-off of the dimmer has a process, requires time, and does not change abruptly according to the characteristics of the triode, as shown in table 1.

TABLE 1 ON-OFF CONDITIONS TABLE OF SILICON CONTROLLED LIGHT REGULATOR

As shown in fig. 5, the existing triac dimmer control circuit is controlled by a constant current IL, and is not divided into segments, and the size of IL can be adjusted only by adjusting a resistor R1, so that it is difficult to be compatible with all dimmers, and the efficiency is low. The conventional scheme driving waveforms are shown in fig. 6.

The existing solutions mainly have the following disadvantages: (1) for example, when the triac dimmer is turned on and the bus voltage VBUS on the rectified dc bus exceeds the starting voltage VLED of the LED, the operating current of the LED will generate enough current for normally turning on or maintaining the triac dimmer, and no bleeding current needs to be generated, and the bleeding current IL will cause extra loss; (2) the leakage current can only be adjusted through R1, and the current cannot be adjusted when R1 is fixed, so that the current is difficult to be compatible with all dimmers.

In view of the above, there is a need to design an LED driving circuit to overcome the above-mentioned drawbacks of the existing LED driving circuits.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: a self-adaptive circuit module is provided, which can improve the efficiency of different systems to the maximum extent and is compatible with all silicon controlled dimmers.

Meanwhile, the invention provides the LED driving circuit with the silicon controlled dimmer, which can improve the efficiency of different systems to the maximum extent and is compatible with all the silicon controlled dimmers.

In addition, the invention also provides a driving method of the LED driving circuit with the silicon controlled dimmer, which can improve the efficiency of different systems to the maximum extent and can be compatible with all the silicon controlled dimmers.

In order to solve the technical problems, the invention adopts the following technical scheme:

an adaptive circuit module applied to an LED driving circuit with a thyristor dimmer, the adaptive circuit module comprising:

the timer is used for detecting the starting time position of the silicon controlled dimmer;

the detector is coupled with the timer and the direct current bus and is used for detecting whether the silicon controlled rectifier dimmer is normally started or not;

and the controller is respectively coupled with the timer, the detector and the bleeder circuit and is used for adaptively controlling the bleeder current of the bleeder circuit according to the feedback results of the timer and the detector.

As a preferred scheme of the present invention, the bleed current includes a pulse current, and the amplitude or pulse width or frequency of the pulse current is adjusted according to the information of whether the dimmer is normally turned on, so that the pulse current reaches the minimum current for normally turning on the corresponding thyristor dimmer; or,

the leakage current comprises direct current, and the magnitude of the direct current is adjusted according to the information whether the dimmer is normally started or not, so that the direct current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer.

As a preferred aspect of the present invention, the controller, which uses pulse current control to adjust the amplitude or the pulse width or the frequency of the pulse current according to the information whether the dimmer is normally turned on, includes:

if the detector detects that the dimmer can be normally opened in N continuous periods, reducing the amplitude of the bleeder current or reducing the pulse width or reducing the frequency according to a given proportion to reduce the average value of the bleeder current; then continuously detecting whether the dimmer can be normally started in N continuous periods; if the dimmer can be normally started in N continuous periods, continuously reducing the amplitude of the leakage current or reducing the pulse width or reducing the frequency according to a given proportion; in the same way, increasing the amplitude or pulse width or frequency of the discharge current to the value which enables the dimmer to be normally turned on last time and then keeping the value unchanged until the detector detects that the dimmer cannot be normally turned on in N continuous periods, wherein the period is the period after the power supply is rectified, N is more than or equal to 2, and N is a natural number;

if the detector detects that the dimmers can not be normally opened in N continuous periods, increasing the amplitude of the bleeder current or increasing the pulse width or increasing the frequency according to a given proportion to increase the average value of the bleeder current; then continuously detecting whether the dimmer can be normally started in N continuous periods; if the dimmer can not be normally started in N continuous periods, continuously increasing the amplitude of the bleeder current or increasing the pulse width or increasing the frequency according to a given proportion; and repeating the steps until the detector detects that the dimmer can be normally opened in N continuous periods, and keeping the amplitude, the pulse width and the frequency of the discharge current unchanged.

As a preferable aspect of the present invention, the controller, which controls the dc current according to a result of detecting whether the dimmer is normally turned on, includes:

under the given initial condition, if the dimmer can be normally started in N continuous periods, reducing the current value according to the proportion set each time until the dimmer can not be normally started, regulating the current value back to the last value, and then fixing the current value, wherein the period is the period after the power supply is rectified, N is more than or equal to 2, and N is a natural number;

under the given initial condition, if the dimmer can not be normally started in N continuous periods, the current value is increased according to the proportion set every time until the dimmer is normally started, and the current value is fixed.

As a preferred aspect of the present invention, the adaptive circuit module further includes an LED turn-on detection unit for detecting whether the LED lamp is turned on, and the controller controls the LED lamp according to a feedback result of the LED turn-on detection unit, the timer, and the detector:

if the LED lamp is started at the starting time of the dimmer, the current does not need to be discharged at the moment;

if the LED lamp is not started at the starting time of the dimmer and the starting position of the dimmer exceeds 50% T, no current is required to be discharged at the moment;

if the LED lamp is not turned on at the time when the dimmer is turned on, and the position where the dimmer is turned on is less than 50% T, the current needs to be discharged at this time.

As a preferred aspect of the present invention, when the LED lamp is turned off and the time position exceeds 50% T, a pulse current with a low frequency or a low pulse width is provided to ensure that the bus voltage can follow the commercial power, and when the bus voltage further decreases to a threshold voltage, a bleed current is provided to reset the triac dimmer.

As a preferred scheme of the present invention, the LED turn-on detection unit includes a zeroth comparator, a first input terminal of the zeroth comparator is coupled to a reference voltage, and a second input terminal of the zeroth comparator is coupled to the constant current control circuit.

As a preferred aspect of the present invention, the controller includes a fourth comparator, a fifth comparator, a sixth comparator, an SR flip-flop, and a sixth capacitor; the controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

the non-inverting input terminal of the fourth comparator 31 is connected to the first terminal of the sixth capacitor, the inverting input terminal of the fifth comparator 32, and the inverting input terminal of the sixth comparator 33, respectively;

the inverting input end of the fourth comparator is connected with a second reference voltage, and the output end of the fourth comparator is connected with the SR trigger; the second end of the sixth capacitor is grounded; the non-inverting input end of the fifth comparator is connected with a third reference voltage, and the output end of the fifth comparator is connected with the SR trigger;

the non-inverting input end of the sixth comparator is connected with a reference voltage, the output end of the sixth comparator is connected with the enabling port of the first power amplifier, the non-inverting input end of the first power amplifier is connected with a fourth reference voltage, the fourth reference voltage determines the amplitude of the bleeder current, and the inverting input end of the first power amplifier is connected with the first end of the first resistor and the source electrode of the first power tube; the output end of the operational amplifier is connected with the grid electrode of the first power tube, the source electrode of the first power tube is connected with the bus voltage, and the second end of the first resistor is grounded;

generating a triangular wave signal by utilizing the charge and discharge of the sixth capacitor, comparing the triangular wave signal with the reference voltage to generate a pulse signal, and controlling the generation of the leakage current by the pulse signal; wherein the pulse width is adjusted by adjusting the magnitude of the reference voltage; adjusting any one or more of the charging and discharging current of the triangular wave signal, the capacitance, the second reference voltage and the third reference voltage to adjust the frequency; and adjusting the fourth reference voltage to adjust the amplitude.

As a preferable scheme of the present invention, the detector includes a first switch, a second switches, a +1 capacitors, an and gate, and a comparators, where a is an integer greater than or equal to 1;

the first ends of the first switch and the second switches are respectively connected with the second end of the third resistor; the second ends of the first switches are respectively connected with the inverting input ends of the comparators, the second ends of the second switches are respectively connected with the non-inverting input ends of the different comparators, the second ends of the second switches are respectively connected with the first ends of the different capacitors, and the second ends of the capacitors are grounded; the output end of each comparator is connected with the input end of the AND gate, and the output end of the AND gate provides a detection result.

An LED driver circuit having a thyristor dimmer, the LED driver circuit comprising: the device comprises a silicon controlled dimmer, a rectifying circuit, a bleeder circuit, a constant current control circuit and a self-adaptive circuit module;

the self-adaptive circuit module is respectively connected with the rectifying circuit, the bleeder circuit and the constant current control circuit, the rectifying circuit is connected with the silicon controlled rectifier dimmer, the bleeder circuit is connected with the constant current control circuit, the constant current control circuit is connected with the LED lamp, and the self-adaptive circuit module is used for self-adaptively controlling the bleeder current in the bleeder circuit at least according to the opening information of the silicon controlled rectifier dimmer.

As a preferred scheme of the present invention, the self-adaptive circuit module drives the scr dimmer through a predetermined pulse current, then detects whether the scr dimmer is normally turned on, and then appropriately adjusts the amplitude or pulse width or frequency of the pulse current according to the detection result, so that the pulse current reaches the minimum current for normally turning on the corresponding scr dimmer;

or the self-adaptive circuit module adopts direct current control with adjustable current value; and directly adjusting the magnitude of the discharge current according to the result of detecting whether the dimmer is normally started, so that the direct current reaches the minimum current of normally starting the corresponding silicon controlled dimmer.

As a preferable aspect of the present invention, the adaptive circuit module includes: the detector, the timer and the controller are respectively connected with the detector and the timer;

the detector is used for detecting whether the silicon controlled rectifier dimmer is normally started or not and sending a detection result to the controller;

the timer is used for detecting the opening position of the silicon controlled dimmer and feeding back acquired information to the detector and the controller;

the controller is used for driving the silicon controlled rectifier dimmer through pulse current with preset fixed amplitude, frequency and pulse width; and after the silicon controlled dimmer is not normally started, adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result to enable the pulse current to reach the minimum current for normally starting the corresponding silicon controlled dimmer.

As a preferred scheme of the present invention, the adaptive circuit module further includes an LED turn-on detection unit for detecting whether the LED lamp is turned on; the controller controls according to the LED starting detection unit, the timer and the feedback result of the detector;

if the LED lamp is not started at the starting time of the silicon controlled dimmer, and the starting time of the silicon controlled dimmer is less than 50% T as known by the counter, the leakage current of the starting interval of the silicon controlled dimmer is needed, wherein T is the period of the power supply after rectification; the initialization state provides an initialization current which has set amplitude, frequency and pulse width;

the controller judges whether the dimmer can be normally started in continuous N periods according to the state of the dimmer detected by the detector, if so, the first step is carried out, otherwise, the second step is carried out;

the method comprises the steps of firstly, if the detector detects that the dimmer can be normally started in N continuous periods, reducing the average value of the leakage current, then continuously detecting whether the dimmer can be normally started in the N continuous periods, if the dimmer can be normally started in the N continuous periods, continuously reducing the average value of the leakage current, and so on, until the detector detects that the dimmer can not be normally started in the N continuous periods, increasing the average value of the leakage current to a value which can normally start the dimmer last time, and then keeping the value unchanged, wherein N is more than or equal to 2, and N is a natural number;

②, if the detector detects that the dimmer can not be normally started in N continuous periods, the average value of the leakage current is increased, then whether the dimmer can be normally started in N continuous periods is continuously detected, if the dimmer can not be normally started in N continuous periods, the average value of the leakage current is continuously increased, and the like until the detector detects that the dimmer can be normally started in N continuous periods, the average value of the leakage current is kept unchanged.

As a preferred aspect of the present invention, the bleeding circuit is configured to provide a bleeding current; the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

the output end of the first power amplifier is connected with the grid electrode of the first power tube, the drain electrode of the first power tube is connected with the bus, and the source electrode of the first power tube is respectively connected with the first end of the first resistor and the inverting input end of the first power amplifier; the non-inverting input end of the first power amplifier is connected with a first main reference voltage, the first power amplifier is connected with the controller, and the second end of the first resistor is connected with the constant current control circuit;

the constant current control circuit comprises a second power amplifier, a second power tube and a second resistor;

the output end of the second power amplifier is connected with the grid electrode of a second power tube, the drain electrode of the second power tube is connected with a second main reference voltage, and the source electrode of the second power tube is respectively connected with the first end of a second resistor, the inverted input end of the second power amplifier, the second end of a first resistor and the inverted input end of a zero comparator; the non-inverting input end of the second power amplifier is connected with a second main reference voltage, and the second end of the second resistor is grounded.

An LED driving method of an LED driving circuit having a thyristor dimmer, the LED driving method comprising:

detecting the opening position of the silicon controlled dimmer;

detecting whether the silicon controlled rectifier dimmer is normally started or not; and

and adaptively adjusting the discharge current in the driving circuit according to the information whether the silicon controlled dimmer is normally started and the information of the starting position of the silicon controlled dimmer.

As a preferred scheme of the invention, the thyristor dimmer is driven by a preset pulse current, then whether the thyristor dimmer is normally started is detected, and the amplitude value or the pulse width or the frequency of the pulse current is adjusted according to the detection result, so that the pulse current reaches the minimum current for normally starting the corresponding thyristor dimmer;

or, the direct current with adjustable current value is adopted for controlling; and directly adjusting the magnitude of the discharge current according to the result of detecting whether the dimmer is normally started, so that the direct current reaches the minimum current of normally starting the corresponding silicon controlled dimmer.

As a preferred aspect of the present invention, a thyristor dimmer is driven by a pulse current of a predetermined fixed amplitude, frequency and pulse width; after the fact that the silicon controlled rectifier dimmer is not normally started is known, the amplitude value or the pulse width or the frequency of the pulse current is adjusted according to the detection result, and the pulse current reaches the minimum current of normally starting the corresponding silicon controlled rectifier dimmer.

The invention has the beneficial effects that: the self-adaptive circuit module, the LED driving circuit with the silicon controlled light modulator and the driving method thereof can be compatible with all the silicon controlled light modulators, and the silicon controlled light modulator can be controlled to be turned on according to pulse currents with different amplitude values or different pulse widths generated by different silicon controlled light modulators, so that the efficiency of different systems can be improved to the maximum extent, and all the silicon controlled light modulators can be compatible.

Drawings

Fig. 1 is a schematic diagram of a one-way thyristor structure.

Fig. 2 is a working principle diagram of a unidirectional thyristor.

Fig. 3 is a schematic diagram of a triac structure.

Fig. 4 is a schematic diagram of a thyristor dimmer.

Fig. 5 is a driving schematic diagram of a conventional triac dimmer circuit.

Fig. 6 is a conventional driving waveform diagram of a conventional triac dimming circuit.

Fig. 7 is a circuit diagram of an LED driving circuit according to an embodiment of the invention.

Fig. 8 is a timing diagram illustrating an operation of an LED driving circuit according to an embodiment of the invention.

Fig. 9 is a circuit diagram of a detector in an LED driving circuit according to an embodiment of the invention.

Fig. 10 is a schematic diagram of a detector in an LED driving circuit according to an embodiment of the invention.

Fig. 11 is a schematic diagram of a counter in an LED driving circuit according to an embodiment of the present invention.

FIG. 12 is a functional block diagram of a controller according to an embodiment of the present invention.

Fig. 13 is a block diagram of a flow of a controller adjusting a pulse current according to an embodiment of the invention.

Fig. 14 is a circuit diagram of a pulse width modulation circuit in an LED driving circuit according to an embodiment of the invention.

Fig. 15 is a schematic diagram of a pulse width modulation circuit in an LED driving circuit according to an embodiment of the invention.

Fig. 16 is a schematic diagram of a normal waveform detected by a detector in an LED driving circuit according to a fifth embodiment of the present invention.

Fig. 17 is a schematic diagram of an abnormal waveform detected by a detector in an LED driving circuit according to a fifth embodiment of the present invention.

Fig. 18 is a timing diagram of a controller controlling according to feedback in an adaptive circuit module according to an embodiment of the present invention.

Fig. 19 is a timing diagram of the controller controlling according to feedback in the adaptive circuit module according to an embodiment of the present invention.

Fig. 20 is a schematic circuit diagram of a controller in an adaptive circuit module according to a sixth embodiment of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

The description in this section is for several exemplary embodiments only, and the present invention is not limited only to the scope of the embodiments described. It is within the scope of the present disclosure and protection that the same or similar prior art means and some features of the embodiments may be interchanged.

"coupled" or "connected" in this specification includes both direct and indirect connections, such as through some active device, passive device, or electrically conductive medium. "plurality" means two or more.

Example one

Referring to fig. 7, the present invention discloses an adaptive circuit module applied to an LED driving circuit with a silicon controlled dimmer, the adaptive circuit module comprising: timer 1, detector 2, controller 3, detector 2, timer 1 are connected respectively to controller 3.

The timer 1 is used for detecting the time position of the start of the silicon controlled rectifier dimmer and feeding back the acquired information to the detector and the controller.

The detector 2 is coupled to the timer and the dc bus, and is configured to obtain a time position of the thyristor dimmer and a bus voltage VBUS, further detect whether the thyristor dimmer is normally turned on according to the time position of the thyristor dimmer and a variation trend of the bus voltage VBUS, and feed back a detection result to the controller.

The controller 3 is respectively connected with the detector 2 and the timer 1 and is used for adaptively controlling the discharge current according to the information whether the silicon controlled dimmer is normally started and the information of the starting position of the silicon controlled dimmer.

In one embodiment, the bleed current comprises a pulsed current comprising a plurality of current pulses in succession. And the controller 3 adjusts the amplitude or the pulse width or the frequency of the pulse current according to the information whether the dimmer is normally started, so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer. Specifically, in one cycle, the controller 3 is configured to drive a thyristor dimmer by presetting a pulse current of fixed amplitude, frequency and pulse width; the method can also be used for adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result after the silicon controlled dimmer is not normally started, so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled dimmer.

In addition, the adaptive circuit module may further include a zeroth comparator 4 for detecting whether the LED lamp 9 is turned on; the controller 3 controls the bleeding current differently according to different feedback results of the zero-th comparator 4, the timer 1 and the detector 2. Of course, the zeroth comparator 4 may also be part of the controller 3.

The working principle of the self-adaptive circuit module of the invention is as follows:

[ working timing diagram ]

Referring to FIG. 8 and Table 1, the duty cycle T is divided into intervals T0-T2, T2-T3, T3-T4, T4-T5, and T5-T0; maintaining the T5 state in the interval of T0-T2; in the interval of T2-T3, the TRIAC is turned on; the LED lamp is conducted between T3 and T4; in the interval of T4-T5, the LED lamp is turned off; VBUS < VF1 in the interval from T5 to T0.

The T4-T5 section only needs to ensure that the VBUS voltage can change along with the mains supply, and does not need to completely turn on the silicon controlled dimmer, so that pulse current with very low frequency and pulse width can be supplied.

In the sections T5 to T0, since VBUS is already low, the triac dimmer needs to be turned on completely, and the triac dimmer can be reset again when the bus voltage before rectification is normal zero crossing, so that the dimmer is driven by a large current to be turned on.

TABLE 2 working timing sequence chart

[ DETECTOR ]

Referring to fig. 7, the adaptive circuit module further includes a voltage dividing resistor, where the voltage dividing resistor includes a third resistor R3 and a fourth resistor R4; the first end of the third resistor is connected with the direct current bus, the second end of the third resistor is respectively connected with the first ends of the detector 2, the timer 1 and the fourth resistor R4, and the second end of the fourth resistor R4 is grounded.

Referring to fig. 9 and 10, the detector 2 includes a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first comparator 21, a second comparator 22, a third comparator 23, an and gate 24, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

The first end of the first switch S1, the first end of the second switch S2, the first end of the third switch S3, and the first end of the fourth switch S4 are respectively connected to the second end of the third resistor R3. A second terminal of the first switch S1 is connected to the first terminal of the second capacitor C2, the inverting input terminal of the first comparator 21, the inverting input terminal of the second comparator 22, and the inverting input terminal of the third comparator 23, respectively, and a second terminal of the second capacitor C2 is grounded. The second end of the second switch S2 is connected to the first end of the third capacitor C3 and the non-inverting input terminal of the first comparator 21, respectively, and the second end of the third capacitor C3 is grounded. The second terminal of the third switch S3 is connected to the first terminal of the fourth capacitor C4 and the non-inverting input terminal of the second comparator 22, respectively, and the second terminal of the fourth capacitor C4 is grounded. A second end of the fourth switch S4 is connected to the first end of the fifth capacitor C5 and the non-inverting input terminal of the third comparator 23, respectively, and a second end of the fifth capacitor C5 is grounded. The output end of the first comparator 21, the output end of the second comparator 22 and the output end of the third comparator 23 are respectively connected with the input end of the and gate 24.

When the dimmer is turned on, the first switch S1 is opened, the voltage at this time is sampled, and then the first switch S1 is turned off. And starting S2 sampling voltage after delaying M%. T (T is the time of the whole period). And similarly, sampling is carried out for N times (the sampling time point of each time cannot exceed 50% T), and if the voltage sampled later is higher than that sampled for the first time, the EN outputs high potential to indicate that the silicon controlled rectifier dimmer is normally started. M is a constant greater than 0 and less than 10.

[ TIMEPIECE ]

Referring to fig. 11, the timer 1 is used to detect the position of the dimmer on and count the number of cycles of VBUS. The dimmer on count is the period of time that the VBUS voltage is counted as being lower than VF 1. And VBUS jumps from below a certain threshold to above the threshold during this time.

[ CONTROLLER ]

Please refer to fig. 12 to 15. FIG. 12 shows a functional block diagram of a controller according to an embodiment of the present invention. The controller receives the outputs of the timer, detector and comparator, the logic control circuit determines the condition, and the pulse modulation circuit further provides and adjusts the VPWM signal.

Fig. 13 shows a block flow diagram of a controller adjusting a pulse current according to an embodiment of the invention. Firstly, whether the pulse signal needs to be adjusted is judged according to a signal whether the LED is started when the silicon controlled rectifier dimmer is started and a signal whether the time position of the silicon controlled rectifier dimmer is started to exceed 50% T. If the LED is not started when the silicon controlled dimmer is started and the starting time position is less than 50% T, pulse current needs to be provided and is adjusted according to the conditions of N periods; if the LED is not started when the silicon controlled dimmer is started, the starting time position exceeds 50% T, or the LED is already started when the silicon controlled dimmer is started, pulse current is not needed, and the EN judgment period is not counted.

And then, judging whether the silicon controlled rectifier dimmer is normally started in N periods according to a judgment signal EN output by the detector, increasing or decreasing the discharge current corresponding to the pulse current, and correspondingly adjusting the current pulse by adjusting the parameter of a pulse width modulation circuit in the controller.

Fig. 14 shows a circuit schematic diagram of a pulse width modulation circuit in a controller, the pulse width modulation circuit of the controller 3 includes a switch, a charging current source, a discharging current source, a fourth comparator 31, a fifth comparator 32, a sixth comparator 33, an SR flip-flop, a sixth capacitor C6, a first power transistor Q1, and a fifth resistor R5 according to an embodiment of the invention. The controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier EA1, a first power tube Q1 and a first resistor R1.

The first end of the change-over switch can be switched between the charging current source and the discharging current source, and the output end of the SR trigger sends a signal to the change-over switch; the second end of the switch is connected to the first end of the sixth capacitor, the non-inverting input of the fourth comparator 31, the inverting input of the fifth comparator 32, and the inverting input of the sixth comparator 33, respectively.

The inverting input end of the fourth comparator 31 is connected with a second reference voltage VREF2, and the output end of the fourth comparator 31 is connected with an SR flip-flop; a second end of the sixth capacitor C6 is grounded; the non-inverting input terminal of the fifth comparator 32 is connected to the third reference voltage VREF3, and the output terminal of the fifth comparator 32 is connected to the SR flip-flop.

The non-inverting input end of the sixth comparator 33 is connected with a reference voltage VF2, the output end of the sixth comparator 33 is connected with an EN port of a first power amplifier EA1, the non-inverting input end of the first power amplifier EA1 is connected with a fourth reference voltage VREF4, the fourth reference voltage VREF4 determines the amplitude of a bleeder current Ibld, and the inverting input end of the first power amplifier EA1 is connected with the first end of a first resistor R1 and the source electrode of a first power tube Q1; the output end of the operational amplifier is connected with the grid electrode of the first power tube Q1, the source electrode of the first power tube Q1 is connected with the bus voltage VBUS, and the second end of the first resistor R1 is grounded.

Wherein VREF2 and VREF3 are reference voltages that generate the lower limit and the upper limit of the triangular wave signal, respectively; VF2 is a reference voltage that controls the pulse width; VREF4 in fig. 14 corresponds to Ref2 in fig. 7.

Pulse current modulation principle: with sufficient charge to the capacitor, a triangular wave signal Vtrig is generated, which is then compared to a reference voltage VF2 to generate a pulse signal VPWM, which controls the generation of current. The pulse width may be adjusted by adjusting the magnitude of the VF 2; the frequency can be adjusted by adjusting the charging and discharging current of the Vtrip, the capacitance, VREF2 and VREF 3; adjusting VREF4 may adjust the amplitude.

The control principle of the controller is as follows:

in the first case:

as shown in the timing chart of fig. 8, when the dimmer is turned on at a large angle and the LED lamp is not turned on at time T2, a Bleed current (i.e., a Bleed current Ibld) from T2 to T3 is required. The initialization state (when just powered on) provides initialization current with set amplitude, frequency and pulse width; in the adjusting process, the fixed amplitude, the fixed frequency and the adjustable pulse width are adopted, or the fixed frequency, the fixed pulse width and the adjustable amplitude are adopted, or the fixed amplitude, the fixed pulse width and the adjustable frequency are adopted.

1. If the EN output is high in N continuous periods, reducing the amplitude or the pulse width or the frequency according to a given proportion; then, continuously detecting whether EN is all high or not in N periods; if the voltage is always high, continuously reducing the amplitude or the pulse width or the frequency according to a given proportion; and so on, until EN goes low, the amplitude or pulse width or frequency is increased back to the last value and then remains unchanged.

2. If not all EN are high in N continuous periods, increasing the amplitude or increasing the pulse width or increasing the frequency according to a given proportion; then, continuously detecting whether EN is all high or not in N periods; if not, continuing to increase the amplitude or the pulse width or the frequency according to a given proportion; and by analogy, the amplitude, the pulse width and the frequency are kept unchanged until the EN output is all high level.

In the second case:

referring to fig. 18, at time T2 when the dimmer is turned on, the VBUS voltage is already higher than the LED lamp turn-on voltage, and the ILED may act as a Bleed current, and the dimmer may keep turning on normally, without the Bleed current of the period T2 to T3.

In the third case:

referring to fig. 19, T2 when the dimmer is turned on exceeds 50% T, and the VBUS voltage is already lower than the LED lamp turn-on voltage, and the LED is in the off state, without the need for the black current in the period T2 to T3.

Example two

Referring to fig. 7, the present invention discloses an adaptive circuit module applied to an LED driving circuit with a silicon controlled dimmer, the adaptive circuit module comprising: detector 2, timer 1, controller 3, detector 2, timer 1 are connected respectively to controller 3.

The detector 2 is used for detecting whether the silicon controlled rectifier dimmer is normally started or not, and feeding back a detection result to the controller 3. The timer 1 is used for detecting the opening position after the silicon controlled dimmer is opened and feeding back the acquired information to the detector 2 and the controller 3; the counter 1 is also used to count the number of cycles of VBUS.

The controller 3 is used for adaptively controlling the discharge current according to the information whether the silicon controlled dimmer is normally opened and the time information of the opening position of the silicon controlled dimmer. The controller 3 drives the thyristor dimmer by a preset pulse current (with a set amplitude, frequency and pulse width); and after the silicon controlled dimmer is not normally started, adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result (the pulse current modulation circuit of the controller realizes the function) so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled dimmer.

In addition, the self-adaptive circuit module further comprises a zeroth comparator 4 for detecting whether the LED lamp is turned on; the non-inverting input end of the zero comparator 4 is connected with a third main reference voltage Ref3, and the inverting input end of the zero comparator is connected with a constant current control circuit; the third main reference voltage Ref3 is used to detect whether the LED lamp is normally turned on.

Besides the zero-th comparator, the LED turn-on detection unit may also adopt other forms, such as a current detection manner, a current sensor, other types of current detection circuits, and the like.

The controller 3 controls the bleeding current differently according to different feedback results of the zero-th comparator 4, the timer 1 and the detector 2. Of course, the zeroth comparator 4 may also be part of the controller.

The controller 3 performs different control processes according to different feedback results of the zeroth comparator 4, the timer 1 and the detector 2;

(1) referring to fig. 18, according to the feedback result of the zero-th comparator 4, if the LED lamp is turned on at the time when the dimmer is turned on, the bleed current Ibld does not need to be adjusted at this time;

(2) referring to fig. 19, according to the feedback result of the zero-th comparator 4, if the LED lamp is not turned on at the time of turning on the dimmer, and the counter knows that the time of turning on the dimmer is over 50% T, it indicates that the voltage at the time of turning on the dimmer is insufficient to turn on the LED lamp, so that the bleed current Ibld is not required to be adjusted;

(3) referring to fig. 8, according to the feedback result of the zero comparator 4, if the scr dimmer is turned on at time T2, the LED lamp is not turned on, and the counter knows that the turn-on time of the dimmer is less than 50% T, then the leakage current Ibld in the turn-on interval of the scr dimmer, i.e., the interval from T2 to T3, is required; the initialization state (when just powered on) provides initialization current with set amplitude, frequency and pulse width; in the adjusting process, the fixed amplitude, the fixed frequency and the adjustable pulse width are adopted, or the fixed frequency, the fixed pulse width and the adjustable amplitude are adopted, or the fixed amplitude, the fixed pulse width and the adjustable frequency are adopted.

if the detector detects that the dimmer is normally started in N continuous periods, the amplitude of the bleeder current Ibld is reduced or the pulse width is reduced or the frequency is reduced according to a given proportion (which can be a set proportion or a set value, an uncertain value, a proportion or even a random value in a certain range) to reduce the average value of the bleeder current Ibld, then whether the dimmer can be normally started in the N continuous periods is continuously detected, if the dimmer can be normally started in the N continuous periods, the amplitude of the bleeder current Ibld is continuously reduced or the pulse width is reduced or the frequency is reduced according to the given proportion, and the like until the detector detects that the dimmer can not be normally started in the N continuous periods, the amplitude or the pulse width or the frequency of the bleeder current Ibld is increased to the value which can normally start the dimmer last time, and then the amplitude or the pulse width or the frequency is kept unchanged, wherein N is more than or equal to 2 and is a natural number;

②, if the detector detects that the dimmer cannot be normally started in N continuous periods, increasing the amplitude of the bleeder current Ibld or increasing the pulse width or increasing the frequency to increase the average value of the bleeder current Ibld according to a given proportion (which can be a set proportion or a set value, an uncertain value, a proportion or even a random value in a certain range), then continuously detecting whether the dimmer can be normally started in the N continuous periods, if the dimmer cannot be normally started in the N continuous periods, continuously increasing the amplitude of the bleeder current Ibld or increasing the pulse width or increasing the frequency according to the given proportion, and so on until the detector detects that the dimmer can be normally started in the N continuous periods, keeping the amplitude, the pulse width and the frequency of the bleeder current Ibld unchanged.

Specifically, the control mode of the controller includes:

(1) referring to fig. 18, if the bus voltage VBUS is already higher than the LED lamp turn-on voltage at time T2 when the scr dimmer is turned on, the current ILED flowing through the LED lamp can serve as the bleed current Ibld, and the dimmer can be kept normally turned on, so the bleed current Ibld in the interval T2 to T3 is not needed;

(2) referring to fig. 19, if the time T2 when the triac dimmer is turned on exceeds 50% T, and the bus voltage VBUS is already lower than the LED lamp turn-on voltage, the LED is in the off state, and the bleed current Ibld in the interval from T2 to T3 is not needed;

(3) referring to fig. 8, if the thyristor dimmer is turned on at a larger angle and the LED lamp is not turned on at time T2, a Bleed current Ibld (Bleed current) from T2 to T3 is required; the initialization state (when just powered on) provides initialization current with set amplitude, frequency and pulse width; in the adjusting process, the fixed amplitude, the fixed frequency and the adjustable pulse width are adopted, or the fixed frequency, the fixed pulse width and the adjustable amplitude are adopted, or the fixed amplitude, the fixed pulse width and the adjustable frequency are adopted;

if the detector detects that the dimmer is normally opened (EN output is high) in N continuous periods, the amplitude is reduced or the pulse width is reduced or the frequency is reduced according to a given proportion, then whether the dimmer is normally opened (EN output is high) is continuously detected in N periods, if the dimmer is normally opened (EN output is high), the amplitude is continuously reduced or the pulse width is reduced or the frequency is continuously reduced according to the given proportion, and the like, until the detector detects that the dimmer cannot be normally opened (EN output is not high), the amplitude or the pulse width or the frequency is increased back to the last value, and then the value is kept unchanged, wherein N is more than or equal to 2, and N is a natural number;

if the detector detects that the dimmer can not be normally opened (EN is not all high) in N continuous periods, increasing the amplitude or increasing the pulse width or increasing the frequency according to a given proportion, then continuously detecting whether the dimmer is normally opened (EN output is not all high) in N periods, if the dimmer is not normally opened (EN is not all high), continuously increasing the amplitude or increasing the pulse width or increasing the frequency according to the given proportion, and so on until the detector detects that the dimmer is normally opened (EN output is all high), keeping the amplitude, the pulse width and the frequency unchanged;

wherein the working period T is divided into intervals of T0-T2, T2-T3, T3-T4, T4-T5 and T5-T0; maintaining the T5 state in the interval of T0-T2; in the interval of T2-T3, the silicon controlled dimmer is started; the LED lamp is conducted between T3 and T4; in the interval of T4-T5, the LED lamp is turned off; VBUS < VF1 in the interval of T5-T0; VF1 is a set detection voltage point;

in the interval from T4 to T5, only the bus voltage VBUS is required to be ensured to change along with the mains supply, the silicon controlled dimmer is not required to be completely started, and pulse current with very low frequency and pulse width can be supplied.

In the interval from T5 to T0, since the bus voltage VBUS is already low, the triac dimmer needs to be turned on completely, so that the unrectified bus voltage can be reset again at the normal zero crossing point, and a large current is needed to drive the triac dimmer to turn on.

Referring to fig. 14, the controller 3 includes a switch, a charging current source, a discharging current source, a fourth comparator 31, a fifth comparator 32, a sixth comparator 33, an SR flip-flop, a sixth capacitor C6, a first power transistor Q1, and a fifth resistor R5.

The inverting input end of the fourth comparator 31 is connected with the VREF2, and the output end of the fourth comparator 31 is connected with the SR flip-flop; a second end of the sixth capacitor C6 is grounded; the non-inverting input terminal of the fifth comparator 32 is connected to VREF3, and the output terminal of the fifth comparator 32 is connected to the SR flip-flop.

The non-inverting input end of the sixth comparator 33 is connected to the reference voltage VF2, the output end of the sixth comparator 33 is connected to the EN port of an operational amplifier (i.e., the first power amplifier EA1 of the bleeder circuit), the non-inverting input end of the operational amplifier is connected to VREF4, and the inverting input end of the operational amplifier is connected to the first end of the first resistor R1 and the source of the first power transistor Q1; the output end of the operational amplifier is connected with the grid electrode of the first power tube Q1, the source electrode of the first power tube Q1 is connected with the bus voltage VBUS, and the second end of the first resistor R1 is grounded.

Generating a triangular wave signal Vtrig by utilizing the charge and discharge of a capacitor, comparing the triangular wave signal with a reference voltage VF2 to generate a pulse signal VPWM, and controlling the generation of current by the pulse signal VPWM; the pulse width is adjusted by adjusting the magnitude of the reference voltage VF 2; the charging and discharging current of the triangular wave signal Vtrip, the capacitance and VREF2 and VREF3 can be adjusted to adjust the frequency; adjusting VREF4 adjusts the amplitude.

As shown in fig. 7, the adaptive circuit module further includes a voltage dividing resistor, where the voltage dividing resistor includes a third resistor R3 and a fourth resistor R4; the first end of the third resistor is connected with the direct current bus, the second end of the third resistor is respectively connected with the detector, the timer and the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is grounded.

The detector 2 comprises a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first comparator, a second comparator, a third comparator, an AND gate, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5.

The first end of the first switch S1, the first end of the second switch S2, the first end of the third switch S3, and the first end of the fourth switch S4 are respectively connected to the second end of the third resistor R3. A second end of the first switch S1 is connected to the first end of the second capacitor C2, the inverting input terminal of the first comparator, the inverting input terminal of the second comparator, and the inverting input terminal of the third comparator, respectively, and a second end of the second capacitor C2 is grounded. The second end of the second switch S2 is connected to the first end of the third capacitor C3 and the non-inverting input terminal of the first comparator, respectively, and the second end of the third capacitor C3 is grounded. The second end of the third switch S3 is connected to the first end of the fourth capacitor C4 and the non-inverting input terminal of the second comparator, respectively, and the second end of the fourth capacitor C4 is grounded. The second end of the fourth switch S4 is connected to the first end of the fifth capacitor C5 and the non-inverting input terminal of the third comparator, respectively, and the second end of the fifth capacitor C5 is grounded. And the output end of the first comparator, the output end of the second comparator and the output end of the third comparator are respectively connected with the input end of the AND gate.

EXAMPLE III

Referring to fig. 7, the present invention discloses an LED driving circuit with a scr dimmer, the LED driving circuit comprising: the device comprises a silicon controlled dimmer 8, a rectifying circuit 7, a discharge circuit 5, a constant current control circuit 6 and a self-adaptive circuit module.

The silicon controlled dimmer 8 is used for cutting off a point of a normal sine waveform to adjust the brightness of a rear LED lamp; the rectifying circuit 7 functions to convert alternating current into direct current; the structures of the bleeder circuit 5 and the constant current control circuit 6 are the same, and a stable current source is generated by using power amplification.

The self-adaptive circuit module is respectively connected with the rectifying circuit 7, the discharge circuit 5 and the constant current control circuit 6, and the rectifying circuit 7 is connected with the silicon controlled rectifier dimmer 8. The self-adaptive circuit module drives the silicon controlled rectifier light modulator 8 through a preset pulse current (the pulse modulation circuit in the controller provides an initial value of the pulse current, and the pulse modulation circuit outputs a pulse signal when the silicon controlled rectifier light modulator is powered on), then detects whether the silicon controlled rectifier light modulator is normally started, and properly adjusts the amplitude value or the pulse width or the frequency of the pulse current according to the detection result (realized through the pulse current modulation circuit), so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier light modulator.

The adaptive circuit module includes: detector 2, timer 1, controller 3, detector 2, timer 1 are connected respectively to controller 3. The detector 2 is used for detecting whether the silicon controlled rectifier dimmer is normally started or not and sending a detection result to the controller 3; the timer 1 is used for detecting the opening position of the silicon controlled dimmer and feeding back acquired information to the detector 2 and the controller 3; the controller 3 is used for driving the silicon controlled rectifier dimmer 8 by presetting pulse current with fixed amplitude, frequency and pulse width; and after the thyristor dimmer is not normally started, adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result to enable the pulse current to reach the minimum current for normally starting the corresponding thyristor dimmer 8.

In addition, the self-adaptive circuit module further comprises a zeroth comparator 4 for detecting whether the LED lamp is turned on; the non-inverting input end of the zero comparator 4 is connected with a third main reference voltage Ref3, and the inverting input end of the zero comparator 4 is connected with the constant current control circuit 6; the third main reference voltage Ref3 is used to detect whether the LED lamp is normally turned on.

The specific processing procedure of the adaptive circuit module can be referred to the description of the first embodiment.

The bleeder circuit 5 comprises a first power amplifier EA1, a first power tube Q1 and a first resistor R1. The output end of the first power amplifier EA1 is connected with the grid of a first power tube Q1, the drain of the first power tube Q1 is connected with a bus, and the source of the first power tube Q1 is respectively connected with the first end of a first resistor R1 and the inverting input end of a first power amplifier EA 1; the non-inverting input end of the first power amplifier EA1 is connected with a first main reference voltage Ref1, the first power amplifier EA1 is connected with the controller, and the second end of the first resistor R1 is connected with the constant current control circuit. The first main reference voltage Ref1 is a reference voltage that controls the bleed current.

The constant current control circuit 6 comprises a second power amplifier EA2, a second power tube Q2 and a second resistor R2. The output end of the second power amplifier EA2 is connected with the grid of a second power tube Q2, the drain of the second power tube Q2 is connected with a second main reference voltage Ref2, and the source of the second power tube Q2 is respectively connected with the first end of a second resistor R2, the inverting input end of a second power amplifier EA2, the second end of a first resistor R1 and the inverting input end of a zero comparator; the non-inverting input end of the second power amplifier EA2 is connected with a second main reference voltage, and the second end of the second resistor R2 is grounded. The second main reference voltage Ref2 is a reference voltage that controls the LED lamp current.

A first end of the rectifying circuit 7 is connected with the thyristor dimmer, a second end of the rectifying circuit is respectively connected with a first end of a third resistor R3, a drain electrode of a first power tube Q1 and an anode of a first diode D1, and a third end of the rectifying circuit is grounded;

the timer 1 is respectively connected with the second end of the third resistor R3 and the first end of the fourth resistor R4, and the timer is connected with the controller; the detector is respectively connected with the second end of the third resistor R3 and the first end of the fourth resistor R4, and the detector is connected with the controller; the second end of the fourth resistor R4 is grounded.

In this embodiment, the LED driving circuit further includes a first diode D1, a first capacitor C1; the cathode of the first diode D1 is connected to the first end of the first capacitor C1 and the anode of the LED lamp, and the drain of the second power tube Q2 is connected to the second end of the first capacitor C1 and the cathode of the LED lamp respectively. The first diode D1 is a diode for preventing current from flowing in the reverse direction, and the first capacitor C1 is used for reducing the current ripple of the LED lamp. Of course, the first diode D1 and the first capacitor C1 are not essential to the invention, and may be replaced by other circuits.

The invention also discloses an LED driving method of the LED driving circuit with the silicon controlled dimmer, which comprises the following steps: the method comprises the steps of driving the silicon controlled rectifier dimmer through a preset pulse current, detecting whether the silicon controlled rectifier dimmer is normally started or not, and adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result, so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer. The specific driving method of the present invention can be seen from the above description of the driving circuit.

Example four

The difference between this embodiment and the third embodiment is that, in this embodiment, the first diode D1 and the first capacitor C1 can be replaced by a stroboscopic circuit.

EXAMPLE five

The difference between this embodiment and the first, second, and third embodiments is that in this embodiment, the detector may adopt other manners. As shown in fig. 16 and 17, the number of rising edges or falling edges in i cycles is counted and compared with the number of cycles obtained by the counter. If the two are equal, the dimmer is considered to be normally switched on; if the number of the rising edges or the falling edges is more, the dimmer is turned on more and does not work normally.

EXAMPLE six

The difference between this embodiment and the first, second, and third embodiments is that in this embodiment, pulse current control may not be adopted, and the controller is configured to adopt direct current control with an adjustable current value, that is, adopt direct current as the bleed current, and directly adjust the magnitude of the bleed current Ibld according to a result of detecting whether the dimmer is normally turned on, so that the direct current reaches a minimum current for normally turning on the corresponding thyristor dimmer.

When the controller adopts direct current control with adjustable current value and directly adjusts the magnitude of the current Ibld according to the result of detecting whether the dimmer is normally opened, the controller is divided into two conditions:

(1) under the given initial condition, if the dimmer can be normally started, reducing the current value according to the proportion set every time until the dimmer can not be normally started, adjusting the current value back to the last value, and then fixing the current value;

(2) under the given initial condition, if the dimmer can not be normally started, the current value is increased according to the proportion set every time until the dimmer is normally started, and the value is fixed.

Referring to fig. 20, the controller includes a first operational amplifier, a third power transistor, a plurality of switches (switch S1-switch Sn), and a plurality of resistors; the non-inverting input end of the first operational amplifier is connected with a fifth reference voltage VREF5, the inverting input end of the first operational amplifier is connected with the source electrode of the third power tube, and the output end of the first operational amplifier is connected with the grid electrode of the third power tube.

The fifth reference voltage VREF5 (which is a fixed reference voltage) generates a plurality of reference voltages with decreasing arithmetic differences through the first operational amplifier, and then gates the required reference voltage as the fourth reference voltage VREF4 with the switches S1 to Sn.

The S1-Sn switch is controlled by a signal generated by the controller, and sequentially increases or decreases the reference voltage required by gating.

EXAMPLE seven

The difference between this embodiment and the first and second embodiments is that in this embodiment, the number of switches and comparators can be selected as required; the detector comprises a first switch S1, a second switches, a +1 capacitors, an AND gate and a comparators, wherein a is an integer greater than or equal to 1. And the output signals of the a comparators are subjected to an AND logic. In the first embodiment, a is 3, and a may have other values, such as 1, 2, 4, 5, 10, and the like.

The first ends of the first switch S1 and the second switches are respectively connected with the second end of a third resistor R3; the second end of the first switch S1 is respectively connected with the inverting input end of each comparator, the second end of each second switch is respectively connected with the non-inverting input end of different comparators, the second end of each second switch is respectively connected with the first end of different capacitors, and the second end of each capacitor is grounded; the output end of each comparator is connected with the input end of the AND gate.

Example eight

The difference between this embodiment and the first and second embodiments is that in this embodiment, the comparator in the adaptive circuit module may be a part of the controller (in the second embodiment, the comparator does not belong to a part of the controller and exists separately).

In summary, the adaptive circuit module, the LED driving circuit with the scr dimmer and the driving method thereof according to the present invention are compatible with all the scr dimmers, and can control the on/off of the scr dimmers according to the pulse currents with different amplitudes or different pulse widths or different frequencies generated by different scr dimmers, so as to improve the efficiency of different systems to the maximum and be compatible with all the scr dimmers.

The description and applications of the invention herein are illustrative and are not intended to limit the scope of the invention to the embodiments described above. Variations and modifications of the embodiments disclosed herein are possible, and alternative and equivalent various components of the embodiments will be apparent to those skilled in the art. It will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, and with other components, materials, and parts, without departing from the spirit or essential characteristics thereof. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.

Claims

1. An adaptive circuit module applied to an LED driving circuit with a silicon controlled rectifier dimmer, the adaptive circuit module comprising:

2. The adaptive circuit module of claim 1, wherein:

the discharge current comprises pulse current, and the amplitude or pulse width or frequency of the pulse current is adjusted according to the information whether the dimmer is normally started, so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer; or,

3. The adaptive circuit module according to claim 2, wherein the controller employs pulsed current control to adjust the amplitude or pulse width or frequency of the pulsed current based on information of whether the dimmer is normally on, including:

4. The adaptive circuit module according to claim 2, wherein the controller employs dc current control to adjust the magnitude of the dc current according to the result of detecting whether the dimmer is normally turned on, and the method comprises:

5. The adaptive circuit module according to claim 1, further comprising an LED on detection unit for detecting whether the LED lamp is on, wherein the controller controls according to feedback results of the LED on detection unit, the timer, and the detector:

6. The adaptive circuit module of claim 1, wherein when the LED lamp is off and the time position exceeds 50% T, a low frequency or low pulse width pulse current is provided to ensure that the bus voltage follows the mains voltage, and when the bus voltage further decreases to a threshold voltage, a bleed current is provided to reset the triac dimmer.

7. The adaptive circuit module of claim 5, wherein:

the LED starting detection unit comprises a zero comparator, wherein a first input end of the zero comparator is coupled with a reference voltage, and a second input end of the zero comparator is coupled with the constant current control circuit.

8. The adaptive circuit module of claim 1, wherein:

the controller comprises a selector switch, a charging current source, a discharging current source, a fourth comparator, a fifth comparator, a sixth comparator, an SR trigger and a sixth capacitor; the controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

the first end of the change-over switch can be switched between the charging current source and the discharging current source, and the output end of the SR trigger sends a signal to the change-over switch; the second end of the change-over switch is respectively connected with the first end of the sixth capacitor, the non-inverting input end of the fourth comparator, the inverting input end of the fifth comparator and the inverting input end of the sixth comparator;

9. The adaptive circuit module of claim 8, wherein:

the detector comprises a first switch, a second switches, a +1 capacitors, an AND gate and a comparators, wherein a is an integer greater than or equal to 1;

10. An LED driver circuit having a thyristor dimmer, the LED driver circuit comprising: the device comprises a silicon controlled dimmer, a rectifying circuit, a bleeder circuit, a constant current control circuit and a self-adaptive circuit module;

11. The LED driver circuit with a thyristor dimmer according to claim 10, wherein: the self-adaptive circuit module drives the silicon controlled rectifier dimmer through a preset pulse current, then detects whether the silicon controlled rectifier dimmer is normally started, and then properly adjusts the amplitude value or the pulse width or the frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer;

12. The LED driver circuit with a thyristor dimmer according to claim 10, wherein:

the adaptive circuit module includes: the detector, the timer and the controller are respectively connected with the detector and the timer;

13. The LED driver circuit with a thyristor dimmer according to claim 12, wherein:

the self-adaptive circuit module also comprises an LED starting detection unit for detecting whether the LED lamp is started; the controller controls according to the LED starting detection unit, the timer and the feedback result of the detector;

14. The LED driver circuit with a thyristor dimmer according to claim 10, wherein:

the bleeder circuit is used for providing a bleeder current; the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

15. An LED driving method of an LED driving circuit having a thyristor dimmer, the LED driving method comprising:

detecting the opening position of the silicon controlled dimmer;

16. The LED driving method according to claim 15, wherein:

driving the silicon controlled rectifier dimmer through a preset pulse current, detecting whether the silicon controlled rectifier dimmer is normally started or not, and adjusting the amplitude or pulse width or frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer;

17. The LED driving method according to claim 16, wherein:

driving a thyristor dimmer by presetting a pulse current with fixed amplitude, frequency and pulse width; after the fact that the silicon controlled rectifier dimmer is not normally started is known, the amplitude value or the pulse width or the frequency of the pulse current is adjusted according to the detection result, and the pulse current reaches the minimum current of normally starting the corresponding silicon controlled rectifier dimmer.