Drive circuit, LED chip, and LED lighting device
By introducing a leakage current control unit into the driving circuit, generating and controlling the leakage current to maintain the opening of the thyristor, the problem of the thyristor being easily turned off is solved, and a stable luminous effect is achieved.
Patent Information
- Application Number
- CN202510108253.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-03-28
AI Technical Summary
In the prior art, the thyristor is prone to be turned off incorrectly, resulting in the problem of flashing the light emitting device.
A driving circuit is designed, including a drain current control unit, which maintains the opening of the thyristor by generating a first drain current upon detection of a rising edge of the output voltage and controlling it to drop to the second drain current at a predetermined slope for a certain period of time.
It effectively avoids the problem of wrongly shutting down the Thyristor, prevents the light emitting device from flickering, and ensures lighting effect.
Smart Images
Figure CN119729947A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of lighting circuits, and more specifically, to a driving circuit, an LED chip, and an LED lighting device. Background Art
[0002] Thyristor dimming is a commonly used dimming method. When the driving circuit of the light-emitting device is connected to the thyristor regulator, when the thyristor regulator is turned on, a minimum holding current is required to maintain the normal opening of the thyristor regulator. If the current is less than the minimum holding current, the thyristor regulator will be turned off.
[0003] When the grid voltage connected to the thyristor regulator is lower than the conduction voltage of the light emitting device, an additional bleeder current needs to be introduced to maintain the normal opening of the thyristor regulator. However, if the existing bleeder current control circuit directly uses the minimum maintenance current as the bleeder current for opening the thyristor regulator, the thyristor regulator may be easily turned off by mistake, causing the light emitting device to flicker. Summary of the invention
[0004] The present application proposes a driving circuit, an LED chip and an LED lighting device to solve the technical problem in the related art that a thyristor regulator is easily shut down by mistake and causes the light-emitting device to flicker.
[0005] In a first aspect, an embodiment of the present application provides a driving circuit for driving a light-emitting device to emit light, including: A discharge current control unit, which is electrically connected between the thyristor regulator and the light-emitting device, generates a first discharge current to keep the thyristor regulator turned on when a rising edge of the output voltage is detected, and controls the first discharge current to decrease to a second discharge current according to a first predetermined slope and maintain the first predetermined time; The output voltage is obtained based on the voltage after the thyristor regulator processes the phase of the line network voltage, and the second discharge current is not less than the current threshold for maintaining the thyristor regulator turned on.
[0006] In a possible implementation, the discharge current control unit includes: an edge detection module, a ramp generator, and a discharge current generation module; The first end of the edge detection module and the first end of the discharge current generation module are both electrically connected between the thyristor regulator and the light emitting device; the second end of the discharge current generation module is used for grounding; the second end of the edge detection module is electrically connected to the first end of the ramp generator, and the second end of the ramp generator is electrically connected to the third end of the discharge current generation module; The edge detection module is used to output a first detection signal when a rising edge of the output voltage is detected; The ramp generator is used to control the ramp voltage at the second end of the ramp generator to decrease from a predetermined voltage according to a second predetermined slope when receiving the first detection signal; The discharge current generating module is used to generate a first discharge current based on a predetermined voltage, and in the process of changing the ramp voltage, control the first discharge current to decrease to a second discharge current according to a first predetermined slope and maintain it for a first predetermined time.
[0007] In a possible implementation, the ramp generator is specifically used to control the predetermined voltage to decrease according to a second predetermined slope until it decreases to zero.
[0008] In one possible implementation, the edge detection module is further configured to output a second detection signal to the ramp generator when detecting that the output voltage drops to a voltage threshold, so that the ramp generator resets the ramp voltage at the second end of the ramp generator to a predetermined voltage based on the second detection signal.
[0009] In a possible implementation, the discharge current generating module includes: an operational amplifier module and a first transistor; The second reference voltage is input to the first positive input terminal of the operational amplifier module, and the second positive input terminal of the operational amplifier module serves as the third terminal of the discharge current generating module; The first inverting input terminal and the second inverting input terminal of the operational amplifier module are respectively grounded and electrically connected to the second terminal of the first transistor; The output end of the operational amplifier module is electrically connected to the control end of the first transistor, and the first end and the second end of the first transistor serve as the first end and the second end of the discharge current generating module respectively.
[0010] In a possible implementation, the operational amplifier module includes: a first operational amplifier, a second operational amplifier, and an adder; The positive input terminal and the negative input terminal of the first operational amplifier are respectively used as the first positive input terminal and the second negative input terminal of the operational amplifier module; The positive input terminal and the negative input terminal of the second operational amplifier are used as the second positive input terminal and the first negative input terminal of the operational amplifier module respectively; The output end of the first operational amplifier and the output end of the second operational amplifier are electrically connected to the adder respectively, and the output end of the adder serves as the output end of the operational amplifier module.
[0011] In a possible implementation, the driving circuit further includes: an output unit; The first end of the output unit is used to be electrically connected to the second end of the light emitting device, the first end of the discharge current control unit is used to be electrically connected to the first end of the light emitting device, and the second end of the output unit is electrically connected to the second end of the discharge current control unit; The output unit is used to control the second end of the output unit to be connected with the second end of the light-emitting device when the output voltage is not less than the lamp voltage threshold, so that the second end of the discharge current control unit is disconnected from the first end of the light-emitting device; when the output voltage is less than the lamp voltage threshold, the second end of the output unit is controlled to be disconnected from the second end of the light-emitting device, so that the second end of the discharge current control unit is connected to the first end of the light-emitting device.
[0012] In a possible implementation, the output unit includes: a third operational amplifier, an adjustment resistor, and a second transistor; The first reference voltage is input to the positive input terminal of the third operational amplifier, and the negative input terminal of the third operational amplifier is electrically connected to the first end of the adjustment resistor; An output terminal of the third operational amplifier is electrically connected to a control terminal of the second transistor; The first end of the second transistor serves as the first end of the output unit, and the second end of the second transistor is electrically connected to the second end of the regulating resistor and serves together as the second end of the output unit.
[0013] In a possible implementation, the driving circuit further includes: a constant power unit; The first end and the second end of the constant power unit are electrically connected to the first end and the third end of the output unit respectively; The constant power unit is used to control the constant power output current output from the second end of the constant power unit to decrease when the input voltage of the first end of the output unit is lower than the first preset voltage or the input voltage of the first end of the output unit is higher than the second preset voltage, so as to reduce the voltage drop from the third end of the output unit to the second end of the output unit and increase the output voltage of the second end of the output unit.
[0014] In a possible implementation, the driving circuit further includes: a rectifier bridge group, a diode and a first capacitor; The input end of the rectifier bridge group is used to be electrically connected to the thyristor regulator, the discharge current control unit is connected between the output end of the rectifier bridge group and the positive electrode of the diode, the negative electrode of the diode is electrically connected to the first end of the first capacitor, and the first end and the second end of the first capacitor are respectively used to be electrically connected to the first end and the second end of the light emitting device; The rectifier bridge group is used to convert the line network voltage into an output voltage after the phase is cut by the thyristor regulator.
[0015] In a second aspect, an embodiment of the present application provides an LED chip, comprising: a thyristor regulator, a light-emitting device, and a driving circuit according to the first aspect; The thyristor regulator is electrically connected to the discharge current control unit and the light emitting device; the light emitting device is an LED lamp.
[0016] In a third aspect, an embodiment of the present application provides an LED lighting device, comprising: the LED chip of the second aspect.
[0017] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include: The driving circuit of the embodiment of the present application includes a discharge current control unit, which can be electrically connected between the thyristor regulator and the light-emitting device. When the rising edge of the output voltage is detected, the first discharge current is generated to maintain the thyristor regulator on, and the first discharge current is controlled to decrease to the second discharge current according to the first predetermined slope and maintain the first predetermined time. Since the output voltage is obtained based on the voltage after the thyristor regulator processes the line network voltage phase, the discharge current control unit can be turned on with a larger first discharge current at the moment of detecting the rising edge of the output voltage after the phase processing, and the first discharge current is decreased to the second discharge current in a ramp-like manner. Since the second discharge current is not less than the current threshold for maintaining the thyristor regulator on, the embodiment of the present application can decrease the discharge current in a ramp-like manner to the maintenance current size of the thyristor regulator, instead of directly using the minimum maintenance current as the discharge current for the thyristor regulator to turn on, thereby avoiding the problem that the thyristor regulator is easily turned off by mistake, and thus will not cause the light-emitting device to flicker, and ensure the lighting effect.
[0018] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A schematic diagram of a structure in which a driving circuit provided in an embodiment of the present application is connected to a thyristor regulator and a light-emitting device; Figure 2 A schematic diagram of a waveform of a ramp voltage as the output voltage changes provided in an embodiment of the present application; Figure 3 A waveform diagram of a driving circuit provided in an embodiment of the present application; Figure 4 A schematic diagram of the structure of a discharge current generating module provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of an operational amplifier module provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of an output unit and a constant power unit electrically connected in an embodiment of the present application. Description of the drawings: 10-discharge current control unit, 101-edge detection module, 102-ramp generator, 103-discharge current generation module, 1031-operational amplifier module; 11- output unit; 12- Constant power unit; 20- Thyristor regulator. DETAILED DESCRIPTION
[0020] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.
[0021] It will be understood by those skilled in the art that, unless specifically stated, the "said" and "the" used herein may also include plural forms. It should be further understood that the wording "including" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the implementation of other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the present technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or it may refer to the connection relationship between the element and the other element through an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein refers to at least one of the items defined by the term, for example, "A and / or B" may be implemented as "A", or as "B", or as "A and B".
[0022] Research has found that thyristor dimming is a commonly used dimming method. The thyristor dimmer uses a phase control method to achieve dimming, that is, the thyristor dimmer is controlled to conduct in every half cycle of the sine wave to obtain the same conduction phase angle. By adjusting the chopping phase of the thyristor dimmer, the conduction phase angle can be changed to achieve dimming.
[0023] In the control system of electronic circuits, when a thyristor is connected, a minimum holding current is required to maintain the normal opening of the thyristor when the thyristor is turned on. If the system current is less than the minimum holding current, the thyristor will be turned off. When the line voltage is less than the LED turn-on voltage, an additional discharge current needs to be introduced to maintain the normal opening of the thyristor. However, since there will be a damping oscillation phenomenon when the discharge current is turned on, the polarity of the discharge current will oscillate between positive and negative during the damping oscillation time. If the minimum holding current is directly used as the opening discharge current, the thyristor will be mistakenly closed, causing the LED light to flicker.
[0024] The driving circuit, LED chip and LED lighting device provided in this application are intended to solve the above technical problems in the prior art.
[0025] The following is a detailed description of the technical solution of the present application and how the technical solution of the present application solves the above technical problems with specific embodiments. It should be noted that the following implementations can refer to, draw on or combine with each other, and the same terms, similar features and similar implementation steps in different implementations will not be described repeatedly.
[0026] See also Figure 1 As shown, the embodiment of the present application provides a structural schematic diagram of connecting a driving circuit with a thyristor regulator and a light emitting device. Figure 1 As shown, the driving circuit is used to drive the light-emitting device to emit light, and the driving circuit includes: a discharge current control unit 10. The discharge current control unit 10 is used to be electrically connected between the thyristor regulator 20 and the light-emitting device. When a rising edge of the output voltage is detected, a first discharge current is generated to keep the thyristor regulator 20 turned on, and the first discharge current is controlled to decrease to a second discharge current according to a first predetermined slope and maintained for a first predetermined time.
[0027] The output voltage is a voltage for driving the light-emitting device obtained after phase processing based on the thyristor regulator 20 , and the second discharge current is not less than a current threshold for maintaining the thyristor regulator 20 turned on.
[0028] Optionally, the discharge current control unit 10 generates a first discharge current when detecting a rising edge of the output voltage, and then directly decreases according to a first predetermined slope, and the first discharge current directly decreases to a second discharge current.
[0029] Specifically, the output voltage is used to drive the light-emitting device to emit light, and the light-emitting device may be an LED lamp. The rising edge is the edge at which the output voltage starts to rise.
[0030] The discharge current of the embodiment of the present application includes a first discharge current and a second discharge current, both of which can turn on the thyristor regulator 20. The phase processing of the thyristor regulator 20 can be a phase-cutting processing, and the thyristor regulator 20 adopts a phase control method to achieve dimming, that is, the thyristor regulator 20 is controlled to turn on in every half cycle of the sine wave to obtain the same conduction phase angle.
[0031] The driving circuit of the embodiment of the present application has a discharge current control unit 10, which can be electrically connected between the thyristor regulator 20 and the light-emitting device. When the rising edge of the output voltage is detected, the first discharge current is generated to maintain the thyristor regulator 20 on, and the first discharge current is controlled to decrease to the second discharge current according to the first predetermined slope and maintain the first predetermined time. Since the output voltage is obtained based on the voltage after the thyristor regulator 20 processes the line network voltage phase, the discharge current control unit 10 can be turned on with a larger first discharge current at the moment of detecting the rising edge of the output voltage after the phase processing, and the first discharge current is decreased to the second discharge current in a ramp-like manner. Since the second discharge current is not less than the current threshold for maintaining the thyristor regulator on, the embodiment of the present application can decrease the discharge current in a ramp-like manner to the maintenance current of the thyristor, instead of directly using the minimum maintenance current as the discharge current for turning on the thyristor regulator 20, thereby avoiding the problem that the thyristor regulator 20 is easily turned off by mistake, and thus will not cause the light-emitting device to flicker, and ensure the lighting effect.
[0032] The driving circuit of the embodiment of the present application can be applicable to the application field of LED chips with thyristor dimming, and can be specifically applied to the ramp-type discharge current control circuit and method for thyristor dimming.
[0033] The embodiment of the present application is to address the problem that the single-stage discharge current in the existing thyristor dimming circuit is prone to cause the LED lamp to flicker, and proposes a ramp-type discharge current control method. When the driving circuit detects the rising edge of the output voltage after the thyristor regulator 20 cuts the phase, it will first be turned on with a larger discharge current, and the discharge current will be reduced to the maintenance current of the thyristor in a ramp manner. The ramp-type discharge current of the embodiment of the present application is more efficient than the two-stage discharge current switching.
[0034] See also Figure 1 As shown, the discharge current control unit 10 includes: an edge detection module 101 , a ramp generator 102 and a discharge current generating module 103 .
[0035] The first end of the edge detection module 101 and the first end of the discharge current generating module 103 are both electrically connected between the thyristor regulator 20 and the light-emitting device; the second end of the discharge current generating module 103 is used for grounding; the second end of the edge detection module 101 is electrically connected to the first end of the ramp generator 102, and the second end of the ramp generator 102 is electrically connected to the third end of the discharge current generating module 103.
[0036] The edge detection module 101 is used to output a first detection signal when a rising edge of the output voltage is detected. The ramp generator 102 is used to control the ramp voltage at the second end of the ramp generator 102 to decrease from a predetermined voltage according to a second predetermined slope when receiving the first detection signal. The discharge current generation module 103 is used to generate a first discharge current based on a predetermined voltage, and during the change of the ramp voltage, control the first discharge current to decrease to a second discharge current according to a first predetermined slope and maintain a first predetermined time.
[0037] Optionally, the second end of the discharge current generating module 103 may be grounded via a predetermined resistor. The discharge current generated by the discharge current generating module 103 is the current after the discharge current generating module 103 is turned on.
[0038] See also Figure 1 As shown, the driving circuit further includes: an output unit 11. A first end of the output unit 11 is used to be electrically connected to a second end of the light emitting device, a first end of the discharge current control unit 10 is used to be electrically connected to a first end of the light emitting device, and a second end of the output unit 11 is electrically connected to a second end of the discharge current control unit 10.
[0039] The output unit 11 is used to control the second end of the output unit 11 to be connected with the second end of the light-emitting device when the output voltage is not less than the lamp voltage threshold, so that the second end of the discharge current control unit 10 is disconnected from the first end of the light-emitting device; when the output voltage is less than the lamp voltage threshold, the second end of the output unit 11 is controlled to be disconnected from the second end of the light-emitting device, so that the second end of the discharge current control unit 10 is connected to the first end of the light-emitting device.
[0040] Specifically, the lamp voltage threshold is the minimum voltage for driving the light-emitting device to emit light. When the output unit 11 is turned on, the discharge current control unit 10 is turned off and does not work. When the output unit 11 is turned off, the discharge current control unit 10 is turned on to provide a discharge current. After the second discharge current is maintained for a first predetermined time, the output unit 11 is turned on, and the discharge current control unit 10 is turned off and does not work.
[0041] Specifically, the second end of the output unit 11 is electrically connected to the second end of the discharge current generating module 103 .
[0042] In some embodiments, the driving circuit further includes: a rectifier bridge group, a diode and a first capacitor.
[0043] The input end of the rectifier bridge group is used to be electrically connected to the thyristor regulator 20, the discharge current control unit 10 is connected between the output end of the rectifier bridge group and the positive electrode of the diode, the negative electrode of the diode is electrically connected to the first end of the first capacitor, and the first end and the second end of the first capacitor are respectively used to be electrically connected to the first end and the second end of the light-emitting device.
[0044] The rectifier bridge group is used to convert the line network voltage into an output voltage after the phase is cut by the thyristor regulator 20.
[0045] See also Figure 1 As shown, Z1 represents a rectifier bridge group, D0 is a diode, C0 is a first capacitor, R1 is a first output resistor, R2 is a second output resistor, and ZD is an LED lamp. 120Vac is the line voltage, OUT is the input voltage VOUT, REXT1 corresponds to the second end of the output unit 11, REXT2 corresponds to the second end of the discharge current generating module 103, TRIAC represents the first end of the discharge current generating module 103, Vslope represents the slope voltage of the second end of the slope generator 102, VREF1 is the first reference voltage, VREF2 is the second reference voltage, and the first output resistor R1 is grounded.
[0046] In some embodiments, the ramp generator 102 is specifically configured to control the predetermined voltage to decrease according to a second predetermined slope until it decreases to zero.
[0047] In some embodiments, the edge detection module 101 is further configured to output a second detection signal to the ramp generator 102 when detecting that the output voltage drops to a voltage threshold, so that the ramp generator 102 resets the ramp voltage at the second end of the ramp generator 102 to a predetermined voltage based on the second detection signal.
[0048] Optionally, the edge detection module 101 may adopt an edge detection circuit capable of performing voltage detection.
[0049] See also Figure 2 As shown, the embodiment of the present application provides a waveform diagram of a ramp voltage changing with the output voltage. Figure 2 As shown, VBUS represents the output voltage, and Vslope represents the slope voltage. The slope generator 102 is initially maintained at a fixed voltage value (i.e., a predetermined voltage). After the edge detection module 101 detects the rising edge of the output voltage VBUS after the thyristor phase-cutting, the slope generator 102 generates a voltage that decreases in a ramp until it reaches zero. When the output voltage VBUS drops to the falling edge threshold of the edge detection module 101, the slope generator 102 is reset to the initial fixed voltage value.
[0050] Combination Figure 1 and Figure 2 As shown, in each mains cycle, the driving circuit of the embodiment of the present application obtains a chopped steamed bun-shaped voltage waveform after the sinusoidal mains passes through the thyristor phase cutting and the rectifier bridge group Z1. The magnitude of the OUT current of the embodiment of the present application is determined by the REXT1 port voltage and the first output resistor R1; the discharge current of the driving circuit is jointly determined by the REXT2 port voltage, the first output resistor R1 and the second output resistor R2.
[0051] The working principle of the driving circuit of the embodiment of the present application includes: in each voltage cycle, when the output voltage is lower than the LED lamp voltage, the output unit 11 is turned off, and the discharge current control unit 10 (i.e., the discharge current generation module 103) provides the maintenance current of the thyristor regulator 20, and the current value is determined by the REXT2 port voltage, the first output resistor R1 and the second output resistor R2. When the line network voltage gradually increases and is greater than the LED lamp voltage, the output unit 11 is turned on, and since the REXT1 voltage is higher than the REXT2 voltage, the discharge current control unit 10 (i.e., the discharge current generation module 103) is turned off. The OUT current of the output unit 11 is the REXT1 port voltage divided by the sum of the first output resistor R1 and the second output resistor R2.
[0052] See also Figure 3 As shown, the embodiment of the present application provides a waveform diagram of a driving circuit. Figure 3 As shown in FIG. 1 , the TRIAC current represents the discharge current generated by the discharge current control unit 10 or the discharge current generating module 103, and the OUT current represents the output current of the output unit 11. Figure 2 The slope voltage in the waveform changes in accordance with the output voltage, and will not be described again.
[0053] In some embodiments, the discharge current generating module 103 includes: an operational amplifier module 1031 and a first transistor.
[0054] The second reference voltage is input to the first positive input terminal of the operational amplifier module 1031, and the second positive input terminal of the operational amplifier module 1031 serves as the third terminal of the discharge current generating module 103; the first reverse input terminal and the second reverse input terminal of the operational amplifier module 1031 are respectively grounded and electrically connected to the second terminal of the first transistor; the output terminal of the operational amplifier module 1031 is electrically connected to the control terminal of the first transistor, and the first terminal and the second terminal of the first transistor serve as the first terminal and the second terminal of the discharge current generating module 103 respectively.
[0055] See also Figure 4 As shown, the present embodiment provides a schematic diagram of the structure of a discharge current generating module 103. Figure 4 As shown, VREF2 represents the second reference voltage, Vslope represents the slope voltage, GND represents grounding, TRIAC represents the first end of the discharge current generating module 103, and REXT2 represents the second end of the discharge current generating module 103. M1 represents the first transistor, and M1 can be selected from NMOS transistors. The operational amplifier module 1031 includes a four-input operational amplifier.
[0056] In some embodiments, the operational amplifier module 1031 includes: a first operational amplifier, a second operational amplifier, and an adder. The positive input terminal and the reverse input terminal of the first operational amplifier are respectively used as the first positive input terminal and the second reverse input terminal of the operational amplifier module 1031; the positive input terminal and the reverse input terminal of the second operational amplifier are respectively used as the second positive input terminal and the first reverse input terminal of the operational amplifier module 1031; the output terminal of the first operational amplifier and the output terminal of the second operational amplifier are respectively electrically connected to the adder, and the output terminal of the adder is used as the output terminal of the operational amplifier module 1031.
[0057] Specifically, the output terminal of the operational amplifier module 1031 outputs a voltage, and the voltage can control the current of the first transistor to be a set discharge current.
[0058] See also Figure 5 As shown, the present embodiment provides a schematic diagram of the structure of an operational amplifier module 1031. Figure 5 As shown, Av1 represents the amplification factor of the first operational amplifier, Av2 represents the amplification factor of the second operational amplifier, Add represents the adder, VREF2 represents the second reference voltage, Vslope represents the slope voltage, GND represents the ground, and REXT2 represents the port voltage of the second end of the discharge current generating module 103.
[0059] based on Figure 4 or Figure 5 The circuit structure shown in the figure shows that the relationship between the REXT2 port voltage VREXT2 and the slope voltage Vslope is: Av1×(VREF2-VREXT2)+Av2×Vslope=0. Therefore, the REXT2 port voltage VREXT2 is: VREF2+Av2 / Av1×Vslope. Therefore, the first predetermined slope of the discharge current in the embodiment of the present application is the second predetermined slope of the slope voltage Vslope multiplied by Av2 divided by Av1.
[0060] After detecting the rising edge of the phase-cutting of the thyristor regulator 20, the edge detection module 101 of the embodiment of the present application controls the ramp generator 102 to generate a ramp voltage, and the ramp generator 102 inputs the ramp voltage to the discharge current generation module 103. The discharge current generation module 103 finally generates a discharge current with a ramp-like change and stabilizes at the maintenance current of the thyristor regulator 20 until the output unit 11 is turned on.
[0061] Continue to see Figure 3As shown, when the VBUS voltage rises, the discharge current generating module 103 generates a discharge current which is first turned on with a current of (VREF2+Av2 / Av1×Vslope) / (R1+R2) and then ramps down to the thyristor's holding current, which is set by the first output resistor R1 and the second output resistor R2, and is VREF2 / (R1+R2). The thyristor holding current will be maintained until the output unit 11 is turned on.
[0062] In some embodiments, the output unit 11 includes: a third operational amplifier, an adjustment resistor, and a second transistor.
[0063] The first reference voltage is input to the positive input terminal of the third operational amplifier, and the reverse input terminal of the third operational amplifier is electrically connected to the first end of the adjusting resistor; the output terminal of the third operational amplifier is electrically connected to the control terminal of the second transistor; the first end of the second transistor serves as the first end of the output unit 11, and the second end of the second transistor is electrically connected to the second end of the adjusting resistor and together serves as the second end of the output unit 11.
[0064] Specifically, the output terminal of the third operational amplifier outputs a voltage, and this voltage can control the current of the second transistor to be the set generated OUT current.
[0065] In some embodiments, the driving circuit further includes: a constant power unit 12. A first end and a second end of the constant power unit 12 are electrically connected to a first end and a third end of the output unit 11, respectively.
[0066] The constant power unit 12 is used to control the constant power output current output from the second end of the constant power unit 12 to decrease when the input voltage of the first end of the output unit 11 is lower than the first preset voltage or the input voltage of the first end of the output unit 11 is higher than the second preset voltage, so as to reduce the voltage drop from the third end of the output unit 11 to the second end of the output unit 11 and increase the output voltage of the second end of the output unit 11.
[0067] Optionally, the first preset voltage and the second preset voltage can be set according to actual conditions, and the first preset voltage is not greater than the second preset voltage.
[0068] See also Figure 6 As shown, the embodiment of the present application provides a schematic diagram of a structure in which an output unit 11 and a constant power unit 12 are electrically connected. Figure 6 As shown, AMP represents the third operational amplifier, R3 represents the adjusting resistor, M2 represents the second transistor, and M2 can be an NMOS transistor.
[0069] The first reference voltage VREF1 of the output unit 11 of the embodiment of the present application sets a suitable port voltage for the REXT1 port, and the constant power unit 12 outputs a control signal (i.e., a constant power current) to the third end of the output unit 11. The control signal generates a corresponding voltage drop on the adjustment resistor R3 according to the size of the line network voltage, and the adjustment resistor R3 can reduce the REXT1 port voltage. At the same time, since the constant power output current output by the second end of the constant power unit 12 is reduced, the voltage drop from the third end of the output unit 11 to the second end of the output unit 11 is reduced, and the output voltage of the second end of the output unit 11 is increased, that is, the REXT1 port voltage is increased.
[0070] In the embodiment of the present application, when the grid voltage fluctuates, the input voltage (i.e., OUT voltage) of the first end of the output unit 11 may be lower than the first predetermined voltage or the input voltage of the first end of the output unit 11 may be higher than the second predetermined voltage. At this time, the constant power unit 12 may control the constant power output current output by the second end of the constant power unit 12 to decrease, thereby reducing the voltage drop from the second end of the output unit 11 to the third end of the output unit 11, increasing the output voltage of the third end of the output unit 11, and increasing the output current of the third end of the output unit 11, which is equivalent to increasing the output power of the light-emitting device, thereby improving the constant power effect of the light-emitting device.
[0071] Based on the same inventive concept, an embodiment of the present application provides an LED chip, including: a thyristor regulator 20, a light-emitting device and a driving circuit of an embodiment of the present application. The thyristor regulator 20 is electrically connected to the discharge current control unit 10 and the light emitting device; the light emitting device is an LED lamp.
[0072] The application in the embodiments of the present application can at least achieve the following technical effects: the LED chip in the embodiments of the present application has a discharge current control unit 10, which can be electrically connected between the thyristor regulator 20 and the light-emitting device. When the rising edge of the output voltage is detected, a first discharge current is generated to keep the thyristor regulator 20 turned on, and the first discharge current is controlled to drop to a second discharge current according to a first predetermined slope and maintained for a first predetermined time. Since the output voltage is obtained based on the voltage after the thyristor regulator 20 phase-processes the line voltage, the discharge current control unit 10 can be turned on with a larger first discharge current at the moment of detecting the rising edge of the output voltage after the phase processing, and the first discharge current is reduced to the second discharge current in a ramp-like manner. Since the second discharge current is not less than the current threshold for maintaining the opening of the thyristor regulator, the embodiment of the present application can reduce the discharge current to the maintenance current of the thyristor in a ramp-like manner, instead of directly using the minimum maintenance current as the discharge current for turning on the thyristor regulator 20, thereby avoiding the problem of the thyristor regulator 20 being easily turned off by mistake, and thus will not cause the light-emitting device to flicker, thereby ensuring the lighting effect.
[0073] Based on the same inventive concept, an embodiment of the present application provides an LED lighting device, including: an LED chip of an embodiment of the present application.
[0074] The LED lighting device provided in the embodiment of the present application includes the LED chip of the embodiment of the present application, and the LED chip includes a driving circuit. The LED lighting device has the same inventive concept and the same beneficial effects as the various embodiments described in the previous driving circuit. The contents not shown in detail in the LED lighting device can be referred to the various embodiments described in the previous embodiments, and will not be repeated here.
[0075] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, changed, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the related art that are similar to those disclosed in this application may also be alternated, changed, rearranged, decomposed, combined, or deleted.
[0076] In the description of the present application, the directions or positional relationships indicated by words such as "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the exemplary directions or positional relationships shown in the accompanying drawings. They are for the convenience of describing or simplifying the description of the embodiments of the present application, and do not indicate or imply that the referred device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present application.
[0077] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.
[0078] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0079] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.
[0080] The above is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the scheme of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.
Claims
1. A driving circuit, characterized in that: Used to drive the light-emitting device to emit light, including: A discharge current control unit, which is electrically connected between the thyristor regulator and the light-emitting device, generates a first discharge current to keep the thyristor regulator turned on when a rising edge of the output voltage is detected, and controls the first discharge current to decrease to a second discharge current according to a first predetermined slope and maintain it for a first predetermined time; The output voltage is obtained based on the voltage after the thyristor regulator processes the phase of the line network voltage, and the second discharge current is not less than a current threshold for maintaining the thyristor regulator turned on.
2. The driving circuit according to claim 1, characterized in that: The discharge current control unit includes: an edge detection module, a ramp generator and a discharge current generation module; The first end of the edge detection module and the first end of the discharge current generation module are both electrically connected between the thyristor regulator and the light emitting device; the second end of the discharge current generation module is used for grounding; the second end of the edge detection module is electrically connected to the first end of the ramp generator, and the second end of the ramp generator is electrically connected to the third end of the discharge current generation module; The edge detection module is used to output a first detection signal when a rising edge of the output voltage is detected; The ramp generator is used to control the ramp voltage at the second end of the ramp generator to decrease from a predetermined voltage according to a second predetermined slope when receiving the first detection signal; The discharge current generating module is used to generate the first discharge current based on the predetermined voltage, and control the first discharge current to decrease to a second discharge current according to a first predetermined slope and maintain it for a first predetermined time during the change process of the ramp voltage.
3. The driving circuit according to claim 2, characterized in that: The ramp generator is specifically used to control the predetermined voltage to decrease according to a second predetermined slope until it decreases to zero.
4. The driving circuit according to claim 2, characterized in that: The edge detection module is further configured to output a second detection signal to the ramp generator when detecting that the output voltage drops to a voltage threshold, so that the ramp generator resets the ramp voltage at the second end of the ramp generator to the predetermined voltage based on the second detection signal.
5. The driving circuit according to claim 2, characterized in that: The discharge current generating module comprises: an operational amplifier module and a first transistor; The first positive input terminal of the operational amplifier module inputs a second reference voltage, and the second positive input terminal of the operational amplifier module serves as the third terminal of the discharge current generating module; The first inverting input terminal and the second inverting input terminal of the operational amplifier module are respectively grounded and electrically connected to the second end of the first transistor; The output end of the operational amplifier module is electrically connected to the control end of the first transistor, and the first end and the second end of the first transistor serve as the first end and the second end of the discharge current generating module respectively.
6. The driving circuit according to claim 5, characterized in that: The operational amplifier module includes: a first operational amplifier, a second operational amplifier and an adder; The positive input terminal and the negative input terminal of the first operational amplifier serve as the first positive input terminal and the second negative input terminal of the operational amplifier module respectively; The positive input terminal and the negative input terminal of the second operational amplifier serve as the second positive input terminal and the first negative input terminal of the operational amplifier module respectively; The output end of the first operational amplifier and the output end of the second operational amplifier are electrically connected to the adder respectively, and the output end of the adder serves as the output end of the operational amplifier module.
7. The driving circuit according to claim 1, characterized in that: Also includes: Output unit; The first end of the output unit is used to be electrically connected to the second end of the light emitting device, the first end of the discharge current control unit is used to be electrically connected to the first end of the light emitting device, and the second end of the output unit is electrically connected to the second end of the discharge current control unit; The output unit is used to control the second end of the output unit to be connected with the second end of the light-emitting device when the output voltage is not less than the lamp voltage threshold, so that the second end of the discharge current control unit is disconnected from the first end of the light-emitting device; when the output voltage is less than the lamp voltage threshold, control the second end of the output unit to be disconnected from the second end of the light-emitting device, so that the second end of the discharge current control unit is connected to the first end of the light-emitting device.
8. The driving circuit according to claim 7, characterized in that: The output unit includes: a third operational amplifier, an adjustment resistor, and a second transistor; The first reference voltage is input to the positive input terminal of the third operational amplifier, and the negative input terminal of the third operational amplifier is electrically connected to the first end of the regulating resistor; The output terminal of the third operational amplifier is electrically connected to the control terminal of the second transistor; The first end of the second transistor serves as the first end of the output unit, and the second end of the second transistor is electrically connected to the second end of the regulating resistor and serves together as the second end of the output unit.
9. The driving circuit according to claim 7, characterized in that: Also includes: Constant power unit; The first end and the second end of the constant power unit are electrically connected to the first end and the third end of the output unit respectively; The constant power unit is used to control the constant power output current output by the second end of the constant power unit to decrease when the input voltage at the first end of the output unit is lower than the first preset voltage or the input voltage at the first end of the output unit is higher than the second preset voltage, so as to reduce the voltage drop from the third end of the output unit to the second end of the output unit and increase the output voltage of the second end of the output unit.
10. The driving circuit according to claim 1, characterized in that: Also includes: A rectifier bridge group, a diode and a first capacitor; The input end of the rectifier bridge group is used to be electrically connected to the thyristor regulator, the discharge current control unit is connected between the output end of the rectifier bridge group and the positive electrode of the diode, the negative electrode of the diode is electrically connected to the first end of the first capacitor, and the first end and the second end of the first capacitor are respectively used to be electrically connected to the first end and the second end of the light emitting device; The rectifier bridge group is used to convert the line network voltage into the output voltage after the phase is cut by the thyristor regulator.
11. An LED chip, characterized in that: include: A thyristor regulator, a light emitting device, and a driving circuit as claimed in any one of claims 1 to 10; The thyristor regulator is electrically connected to the discharge current control unit and the light emitting device; the light emitting device is an LED lamp.
12. An LED lighting device, characterized in that: include: The LED chip as claimed in claim 11.