CN220985895U

CN220985895U - Dimming circuit and lighting system

Info

Publication number: CN220985895U
Application number: CN202322743615.0U
Authority: CN
Inventors: 陈小平
Original assignee: Meixinsheng Technology Beijing Co ltd
Current assignee: Meixinsheng Technology Beijing Co ltd
Priority date: 2023-10-12
Filing date: 2023-10-12
Publication date: 2024-05-17
Anticipated expiration: 2033-10-12

Abstract

The application provides a dimming circuit and a lighting system, and relates to the technical field of lighting control. The circuit comprises: the device comprises a dimmer, a rectifier bridge, a charge-discharge branch and a load branch; the dimmer is connected with a rectifier bridge, and the rectifier bridge is connected with a charge and discharge branch and a load branch; the dimmer is used for controlling the charge and discharge branch and the load branch according to the input current and the input voltage; the rectifier bridge is used for splitting the input current into a first branch current input into the charge-discharge branch and a second branch current input into the load branch under the condition that the input voltage is larger than the working voltage of the load branch; the first branch current is used for charging the charging and discharging branch circuit, and the second branch current is used for providing electric energy for the load branch circuit; the charging and discharging branch circuit is also used for providing discharging current for the load branch circuit based on the electric energy stored by charging under the condition that the input voltage is less than or equal to the working voltage of the load branch circuit; wherein the discharge current provides electrical energy to the load branch.

Description

Dimming circuit and lighting system

Technical Field

The application relates to the technical field of illumination control, in particular to a dimming circuit and an illumination system.

Background

Along with the development of the application of the LED lighting fixture, the application of the dimmer for dimming the LED lighting fixture is also becoming wider and wider. However, because there is a power difference between the current dimmer and the LED lamp, the power of the dimmer is larger than that of the LED lamp, resulting in too small current flowing through the dimmer during operation, and the dimmer works abnormally, so that the on time of the LED lamp needs to be reduced to increase the current, the compatibility is poor, the stroboscopic situation is serious, and the lighting effect of the lighting system is poor.

Disclosure of utility model

Accordingly, an objective of the present application is to provide a dimming circuit and a lighting system, so as to solve the problem of poor lighting effect of the lighting system in the prior art.

In order to solve the above problems, an embodiment of the present application provides a dimming circuit, including: the device comprises a dimmer, a rectifier bridge, a charge-discharge branch and a load branch;

the light modulator is connected with the rectifier bridge, and the rectifier bridge is connected with the charge and discharge branch circuit and the load branch circuit;

the dimmer is used for controlling the charge and discharge branch circuit and the load branch circuit according to input current and input voltage;

The rectifier bridge is used for splitting the input current into a first branch current input to the charge and discharge branch and a second branch current input to the load branch under the condition that the input voltage is larger than the working voltage of the load branch; the first branch current is used for charging the charging and discharging branch circuit, and the second branch current is used for providing electric energy for the load branch circuit;

The charging and discharging branch circuit is further used for providing a discharging current for the load branch circuit based on the stored electric energy in a charging mode under the condition that the input voltage is smaller than or equal to the working voltage of the load branch circuit; wherein the discharge current provides electrical energy to the load branch.

In the implementation process, a dimmer is arranged in the dimming circuit to perform dimming control on the load branch. When the input voltage is larger than the working voltage of the load branch, the rectifier bridge divides the input current output by the dimmer so as to flow through the charge and discharge branch and the load branch respectively. The charging and discharging branch circuit can be charged according to the first branch current flowing through the charging and discharging branch circuit, and the load branch circuit can be conducted to work according to the second branch current flowing through the charging and discharging branch circuit. And under the condition that the input voltage is smaller than or equal to the working voltage of the load branch, the charge and discharge branch stops charging, and discharge current is provided for the load branch based on the electric energy stored by charging, so that the load branch continues to conduct work, the conduction time of the load branch is prolonged, the stroboscopic condition on the load branch and the ripple wave of current are reduced, the lighting efficiency is improved, and the compatibility of the dimming circuit is effectively improved.

Optionally, the circuit further comprises: a dimmer current bias branch; the dimmer current bias branch is connected with the rectifier bridge;

The rectifier bridge is used for inputting initial current flowing through the dimmer into the dimmer current bias branch circuit when the dimmer is closed; the dimmer current bias branch is used for charging the dimmer based on the initial current, so that the input current flowing through the dimmer is greater than or equal to the maintenance current of the dimmer, and the dimmer is started.

In the implementation process, when the current flowing through the dimmer is smaller than the maintenance current of the dimmer, the dimmer cannot be started normally, so that abnormal dimming and other conditions are caused, and therefore, a corresponding dimmer current bias branch circuit is further arranged in the circuit, under the condition that the dimmer is closed, the initial current output by the dimmer is input into the dimmer current bias branch circuit by the rectifier bridge, and the dimmer is charged by the dimmer current bias branch circuit based on the initial current, so that the input current finally flowing through the dimmer is larger than or equal to the maintenance current of the dimmer, and the dimmer is started to perform dimming operation. The dimmer can be charged under the conditions that the power difference between the dimmer and the load branch circuit is larger and the initial current flowing through the dimmer is smaller, so that the dimmer can be started normally, the dimmer is suitable for dimmers and load lamps with different power levels, and the compatibility of a dimming circuit is effectively improved.

Optionally, the rectifier bridge is configured to input the input current output by the dimmer into the dimmer current bias branch when the dimmer is on and the input voltage is lower than the operating voltage of the load branch; the dimmer current bias branch is operable to maintain the dimmer on based on the input current.

In the implementation process, since the input voltage will change periodically, when the dimmer is turned on, the input current flowing through the dimmer will also decrease under the condition that the input voltage is lower than the working voltage of the load branch, and the reduced input current may be lower than the maintenance current of the dimmer, so that the dimmer has frequent switching in the use process, and the normal operation of the dimmer is affected. The current bias branch of the dimmer can be continuously conducted to charge the dimmer under the condition that the dimmer is started and the input voltage is lower than the working voltage, so that the continuous conduction of the dimmer is maintained under the condition that the input voltage is smaller, the frequent switching condition of the dimmer is effectively reduced, the dimming effect of the dimmer is optimized, and the lighting efficiency is improved.

Optionally, wherein the dimmer current bias branch comprises: a first transistor and a first comparator;

The first transistor is connected with the rectifier bridge and the ground terminal, and the first comparator is connected with the first transistor;

The first comparator is used for controlling the first transistor to be turned on or turned off based on the input voltage and a first reference voltage.

In the implementation process, the first transistor and the first comparator are arranged in the dimmer current bias branch, and the first comparator controls the on or off of the first transistor according to the input voltage and the first reference voltage, so that the on and off of the dimmer current bias branch are controlled, and the dimmer current bias branch is conducted to charge the dimmer when charging is needed.

Optionally, wherein the dimmer current bias branch further comprises: an energy-saving controller;

The energy-saving controller is connected with the first comparator and is used for controlling the first transistor to be turned off under the condition that the input voltage is larger than the working voltage.

In the implementation process, when the input voltage is greater than the working voltage of the load branch, the input current flowing through the dimmer is greater, so that the dimmer can be kept to be conducted normally to work, therefore, a corresponding energy-saving controller can be arranged in the current bias branch of the dimmer, so that the first transistor is controlled to be turned off in a time period capable of keeping the dimmer to work normally, the current bias branch of the dimmer is turned off, and unnecessary power consumption in the current bias branch of the dimmer is reduced.

Optionally, the charging and discharging branch circuit includes: the first diode, the charge-discharge assembly, the second diode, the second transistor and the second comparator;

The first diode is connected with the rectifier bridge and the charge-discharge assembly, the second diode is connected with the charge-discharge assembly, the second transistor is connected with the charge-discharge assembly and the ground, and the second comparator is connected with the second transistor;

the first diode is used for transmitting the first branch current to the charging and discharging component;

the charging and discharging component is used for charging based on the first branch current;

The charging and discharging assembly is further used for discharging the load branch circuit based on the second diode under the condition that the input voltage is smaller than or equal to the working voltage so as to provide the discharging current for the load branch circuit;

The second comparator is used for controlling the second transistor to be turned on or turned off based on the input voltage and a second reference voltage.

In the implementation process, two diodes, a second transistor, a second comparator and a charging and discharging assembly for charging and discharging are arranged in the charging and discharging branch. The first diode transmits the split first branch current to the connected charging and discharging assembly so that the charging and discharging assembly charges based on the first branch current, and under the condition that the input voltage is smaller than or equal to the working voltage of the load branch, the input source cannot provide enough voltage for the load branch to work, the charging and discharging assembly stops charging and discharges to the load branch based on the connected second diode so as to provide discharge current for the load branch to continuously work. The second comparator controls the on or off of the second transistor according to the input voltage and the second reference voltage, thereby controlling the on and off of the charge-discharge branch, controlling the charge-discharge assembly to carry out electrolytic discharge when the discharge is required, connecting the load branch to carry out discharge when the discharge is required, filling the working current of the load branch, reducing the interruption time and current ripple of the current on the load branch, and prolonging the on time of the load branch.

Optionally, the charging and discharging branch further includes: a first linear compensation assembly; the first linear compensation component is connected with the second comparator;

The first linear compensation component is configured to reduce the second reference voltage in the event of an increase in the input voltage.

In the implementation process, since the input voltage will generate periodic variation, a corresponding first linear compensation component can be arranged in the charge-discharge branch circuit, so that the second reference voltage is reduced under the condition that the input voltage is increased, the power of each component in the charge-discharge branch circuit is stable, and adverse effects of power variation on the components are reduced.

Optionally, the load branch includes: a third transistor, a third comparator, and at least one load component;

the load assembly is connected with the rectifier bridge, the third transistor is connected with the load assembly and the ground, and the third comparator is connected with the third transistor;

The load assembly is used for operating based on the second branch current under the condition that the input voltage is larger than the operating voltage;

The load assembly is further configured to operate based on the discharge current if the input voltage is less than or equal to the operating voltage;

the third comparator is used for controlling the third transistor to be turned on or turned off based on the input voltage and a third reference voltage.

In the above implementation, the third transistor, the third comparator and at least one load component for illumination are provided in the load branch. Under the condition that the input voltage is larger than the working voltage of the load assembly, the load assembly can work normally based on the split second branch current; under the condition that the input voltage is smaller than or equal to the working voltage of the load component, the input source cannot provide enough voltage for the load component to work, and the load component can acquire the discharging current in the charging and discharging branch circuit to work. The third comparator controls the on or off of the third transistor according to the input voltage and the third reference voltage, so that the on and off of the load branch are controlled, the load branch is conducted to work when the load branch can work normally, the charge and discharge branch is connected to continue to work when the input voltage is reduced to the condition that the load branch cannot work normally, the interruption time and current ripple of current on the load branch are reduced, and the on time of the load branch is prolonged.

Optionally, the load branch further includes: a second linear compensation assembly; the second linear compensation component is connected with the third comparator;

The second linear compensation component is configured to reduce the third reference voltage in the event of an increase in the input voltage.

In the implementation process, since the input voltage will generate periodic variation, a corresponding second linear compensation component can be arranged in the load branch circuit, so that the third reference voltage is reduced under the condition that the input voltage is increased, the power of each component in the load branch circuit is stable, and adverse effects of the power variation on the components are reduced.

Optionally, the load branch further includes: a ripple removing component; the ripple removing component is connected with the load component;

The ripple removal component is configured to reduce current ripple of the load component.

In the implementation process, in order to further reduce the current ripple of the load component, the load branch circuit may further be provided with a ripple removing component connected with the load component, so as to reduce the interruption condition of the current flowing through the load component, and make the current waveform flowing through the load component approach to a stable straight line state, thereby reducing the current ripple condition and improving the illumination stability of the load component.

In a second aspect, an embodiment of the present application further provides a lighting system, which includes the dimming circuit according to any one of the first aspects.

In the implementation process, the dimming circuit is arranged in the various types of lighting systems, so that the lighting lamp with the various types of dimmers can be compatible for use, the stroboscopic condition during lighting is effectively reduced under the condition that the lighting efficiency is not reduced, and a stable and high-efficiency lighting function is provided.

In summary, the embodiment of the application provides a dimming circuit and a lighting system, which are provided with a charging and discharging branch circuit, and charge is performed when an input voltage is larger, and a discharging current is provided for a load branch circuit based on electric energy stored in charging at the input voltage, so that the load branch circuit continues to conduct work, thereby prolonging the conduction time of the load branch circuit, reducing the stroboscopic condition and the current ripple on the load branch circuit, improving the lighting efficiency, and being capable of setting a plurality of dimmers of different types to perform dimming work, and effectively improving the compatibility of the dimming circuit.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a dimming circuit according to an embodiment of the present application;

Fig. 2 is a schematic structural diagram of another dimming circuit according to an embodiment of the present application;

Fig. 3 is a schematic diagram of a specific structure of a dimming circuit according to an embodiment of the present application.

Icon: 110-a charge-discharge branch; 120-load branch; 130-dimmer current bias branch; an AC-AC input source; dimmer-dimmers; DB-rectifier bridge; iin-input current; vin-input voltage; v _LED -operating voltage; ic-a first branch current; i _LED -a second branch current; EA 1-a first comparator; MOS 1-a first transistor; VREF 1-a first reference voltage; con 1-energy saving controller; d1-a first diode; c1-a charge-discharge assembly; d2—a second diode; EA 2-second comparator; a MOS 2-second transistor; VREF 2-a second reference voltage; con 2-a first linear compensation component; if-discharge current; LEDn-load components; EA 3-third comparator; a MOS 3-third transistor; VREF 3-a third reference voltage; con 3-a second linear compensation component; chip-ripple removing chip; a C2-capacitor assembly; r1-a first resistor; r2-a second resistor; r3-a third resistor; r4-fourth resistance.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art based on embodiments of the present application without making any inventive effort, are intended to fall within the scope of the embodiments of the present application.

At present, the power difference exists between the dimmer and the LED lamp, and compared with the power of the LED lamp, the power of the dimmer is larger, for example, the use power of the dimmer on the market is generally 40-600W, and the power of most of the LED lamps is only about 10W, so that the current flowing through the dimmer is too small, and the dimmer works abnormally. For some low-power LED lamps, such as less than 5W, the input current is particularly low, and most dimmers on the market cannot be compatible for use. In order to better be compatible with more types of dimmers, the current scheme generally reduces the on time of an LED lamp to increase the current flowing through the dimmer, so that the LED current is interrupted for a long time, and the stroboscopic effect is serious when the LED current is illuminated, in order to solve the stroboscopic effect, a strong stroboscopic effect removing circuit parameter needs to be added for a 50Hz power grid application scene, but the illumination efficiency of an illumination system is lower due to the mode, the overall illumination effect of the illumination system is poor, and the current illumination requirement cannot be met.

In order to solve the above problems, embodiments of the present application provide a dimming circuit that can be provided in various lighting systems, such as a vehicle-mounted lighting system, an indoor/outdoor lighting system, a mobile device lighting system, etc., and can be used in a dimmer and a lighting fixture compatible with various different powers, providing a stable and efficient lighting function.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a dimming circuit according to an embodiment of the present application, where the dimming circuit may include: dimmer Dimmer, rectifier bridge DB, charge and discharge leg 110, and load leg 120, dimmer Dimmer connects rectifier bridge DB, which connects charge and discharge leg 110 and load leg 120.

The dimmer Dimmer is configured to control the charging and discharging branch 110 and the load branch 120 according to the input current Iin and the input voltage Vin. The input voltage Vin is a voltage signal with periodic variation output by alternating current sent by an alternating current input source AC after passing through the dimmer Dimmer, and the voltage signal is rectified by the rectifier bridge DB to obtain a corresponding input current Iin with periodic variation. Optionally, the dimmer Dimmer may be a plurality of types of silicon controlled dimmers with different powers, and the silicon controlled dimmers may include a front cut dimmer and a rear cut dimmer, and when the current in the circuit changes, the resistance of the silicon controlled dimmers also changes, so as to control the on-off of the alternating current and adjust the brightness of the light. For example, the thyristors may be reversely connected twice by two thyristors, which functions not only as rectification, but also as fast switching on or off of a contactless switch, realizing inversion of direct current into alternating current, changing alternating current of one frequency into alternating current of another frequency, etc., and the resistance of the thyristor dimmer may be adjusted in the period of alternating current to change the charging rate of the capacitor therein, so as to make the time of triggering on of the thyristors move forward or backward, i.e. realize the purpose of dimming by changing the magnitude of the conduction angle of the thyristors.

The charge and discharge branch 110 and the load branch 120 may be connected in parallel, and the operating voltage V _LED of the load branch 120 is a lighting voltage for normally lighting the load component LEDn in the load branch 120. The rectifier bridge DB is configured to split the input current Iin into the first branch current Ic of the input charge-discharge branch 110 and the second branch current I _LED of the input load branch 120 when the input voltage Vin is greater than the operating voltage V _LED of the load branch 120. The first branch current Ic is used for charging the charge and discharge branch 110, and the second branch current I _LED provides electric energy for the load branch 120, so that the load branch 120 can work normally based on the second branch current I _LED, and the magnitudes of the first branch current Ic and the second branch current I _LED can be set and modified according to the actual conditions of the charge and discharge branch 110 and the load branch 120.

Optionally, in the case that the input voltage Vin is less than or equal to the operating voltage V _LED of the load branch 120, the charge-discharge branch 110 can stop charging, and provide the load branch 120 with the discharge current I _f based on the stored electrical energy of the charging, and the discharge current If provides the load branch 120 with electrical energy, so that the load branch 120 can continue to operate for a period of time when the input voltage Vin is less than the operating voltage V _LED. The on time of the load branch 120 can be prolonged, so that the stroboscopic condition and the current ripple on the load branch 120 are reduced, the lighting efficiency is improved, and the compatibility of the dimming circuit is effectively improved.

Optionally, referring to fig. 2, fig. 2 is a schematic structural diagram of another dimming circuit according to an embodiment of the present application, where the dimming circuit may further include: the dimmer current bias branch 130, the dimmer current bias branch 130 is connected to the rectifier bridge DB, and the dimmer current bias branch 130, the charge and discharge branch 110 and the load branch 120 may be connected in parallel.

Note that, the dimmer Dimmer has a corresponding holding current, for example, the holding current is 30mA, and when the current flowing through the dimmer Dimmer is smaller than the holding current of the dimmer Dimmer, the dimmer Dimmer cannot be started normally, which may cause abnormal dimming. Thus, with dimmer Dimmer off, dimmer current bias circuit 130 is turned on, forming a loop with dimmer Dimmer, rectifier bridge DB is used to input an initial current through dimmer Dimmer to dimmer current bias circuit 130, and dimmer current bias circuit 130 is capable of charging dimmer Dimmer based on the initial current, such that input current Iin through dimmer Dimmer is greater than or equal to the holding current of dimmer Dimmer to turn on dimmer Dimmer. The dimmer Dimmer can be charged to the dimmer Dimmer under the conditions that the power difference between the dimmer Dimmer and the load branch 120 is larger and the initial current flowing through the dimmer Dimmer is smaller so that the dimmer Dimmer can be started normally, and the method is suitable for dimmers Dimmer and load lamps with different power levels, and the compatibility of a dimming circuit is effectively improved.

In addition, since the input voltage Vin will change periodically, when the dimmer Dimmer is turned on and the input voltage Vin is lower than the operating voltage V _LED of the load branch 120, the input current Iin flowing through the dimmer Dimmer will also decrease, and the decreased input current Iin may be lower than the holding current of the dimmer Dimmer, which results in frequent switching of the dimmer Dimmer during use, which affects the normal operation of the dimmer Dimmer. When the dimmer Dimmer is turned on and the input voltage Vin is lower than the operating voltage V _LED of the load branch 120, the dimmer current bias branch 130 is turned on to form a loop with the dimmer Dimmer, the rectifier bridge DB is used for inputting the input current Iin output by the dimmer Dimmer into the dimmer current bias branch 130, and the dimmer current bias branch 130 can maintain the conduction of the dimmer Dimmer based on the input current Iin, so that the dimmer Dimmer is maintained to be continuously turned on under the condition that the input voltage Vin is smaller, the frequent switching condition of the dimmer Dimmer is effectively reduced, the dimming effect of the dimmer Dimmer is optimized, and the lighting efficiency is improved.

Optionally, referring to fig. 3, fig. 3 is a schematic structural diagram of a dimming circuit according to an embodiment of the present application, where the dimmer current bias circuit 130 may include: a first transistor MOS1 and a first comparator EA1. The first transistor MOS1 is connected to the rectifier bridge DB and the ground terminal, and the first comparator EA1 is connected to the first transistor MOS1. Corresponding first resistor R1 and second resistor R2 may be further disposed at two ends of the first transistor MOS1, so that the dimmer current bias branch 130 can operate normally, and the resistance value of the first resistor R1 and the resistance value of the second resistor R2 may be set and adjusted according to the actual situation of the dimmer current bias branch 130.

The first comparator EA1 is connected to the first reference voltage VREF1, and is capable of controlling the first transistor MOS1 to be turned on or off based on the input voltage Vin and the first reference voltage VREF 1. For example, the first reference voltage VREF1 may be set to a voltage value interval related to the operating voltage V _LED of the load branch 120, and when the input voltage Vin is less than or equal to the first reference voltage VREF1, the first transistor MOS1 is controlled to turn on to charge the dimmer Dimmer, so as to turn on the dimmer current bias branch 130 to charge the dimmer Dimmer when charging is required.

Optionally, the dimmer current bias circuit 130 may further comprise: the energy-saving controller con1, the energy-saving controller con1 is connected to the first comparator EA1, and when the input voltage Vin is greater than the operating voltage V _LED, the input current Iin flowing through the dimmer Dimmer is greater, so that the normal conduction of the dimmer Dimmer can be maintained, therefore, the energy-saving controller con1 can control the first transistor MOS1 to be turned off when the input voltage Vin is greater than the operating voltage V _LED, so as to turn off the dimmer current bias branch 130, reduce unnecessary power consumption in the dimmer current bias branch 130, and further save the power consumption of the dimming circuit.

Alternatively, the charge and discharge branch 110 may include: a first diode D1, a charge-discharge component C1, a second diode D2, a second transistor MOS2, and a second comparator EA2. The first diode D1 is connected with the rectifier bridge DB and the charge-discharge assembly C1, the second diode D2 is connected with the charge-discharge assembly C1, the second transistor MOS2 is connected with the charge-discharge assembly C1 and the ground terminal, and the second comparator EA2 is connected with the second transistor MOS2.

For example, the charge and discharge assembly C1 may be provided as a capacitor assembly C2 to implement respective charge and discharge functions.

Optionally, one end of the second transistor MOS2 may be further connected to a corresponding third resistor R3, so that the charge-discharge branch 110 can operate normally, and the resistance value of the third resistor R3 may be set and adjusted according to the actual situation of the charge-discharge branch 110.

It should be noted that, the first diode D1 transmits the split first branch current Ic to the connected charging and discharging component C1, so that the charging and discharging component C1 charges based on the first branch current Ic, and when the input voltage Vin is less than or equal to the operating voltage V _LED of the load branch 120, the AC input source AC cannot provide enough voltage for the load branch 120 to operate, the charging and discharging branch 110 and the load branch 120 are disconnected from the rectifier bridge DB, the charging and discharging component C1 stops charging, and forms a loop with the load branch 120 based on the connected second diode D2, so as to discharge to the load branch 120, so as to provide the discharging current If for the load branch 120 to continuously operate. The second comparator EA2 controls the second transistor MOS2 to be turned on or off according to the input voltage Vin and the second reference voltage VREF2, thereby controlling the charge-discharge branch 110 to be turned on or off. For example, the second reference voltage VREF2 may also be set to a voltage value interval related to the operating voltage V _LED, and when the input voltage Vin is greater than the second reference voltage VREF2, the second transistor MOS2 is controlled to be turned on, so as to turn on the charging/discharging branch 110 for charging when charging is required; when the input voltage Vin is smaller than or equal to the second reference voltage VREF2, the second transistor MOS2 is controlled to be turned off, so that the charging and discharging component C1 is controlled to perform electrolytic discharging when discharging is required, thereby filling the working current of the load branch 120, reducing the interruption time and current ripple of the current on the load branch 120, and prolonging the conduction time of the load branch 120.

Alternatively, the load branch 120 may include: the third transistor MOS3, the third comparator EA3 and at least one load component LEDn, wherein the load component LEDn is connected with the rectifier bridge DB, the third transistor MOS3 is connected with the load component LEDn and the ground terminal, and the third comparator EA3 is connected with the third transistor MOS3.

By way of example, the load assembly LEDn may be provided as a plurality of different models, different power LED light fixture devices.

Optionally, one end of the third transistor MOS3 may be further connected to a corresponding fourth resistor R4, so that the load branch 120 can operate normally, and the resistance value of the fourth resistor R4 may be set and adjusted according to the actual situation of the load branch 120.

It should be noted that, when the input voltage Vin is greater than the operating voltage V _LED of the load component LEDn, the load component LEDn can perform normal operation based on the split second branch current I _LED; when the input voltage Vin is less than or equal to the operating voltage V _LED of the load component LEDn, the AC input source AC cannot provide enough voltage for the load component LEDn to operate, the charging and discharging branch 110 and the load branch 120 are disconnected from the rectifier bridge DB, and the load component LEDn can obtain the discharging current If in the charging and discharging branch 110 to continue to operate. The third transistor MOS3 is controlled to be turned on or off by the third comparator EA3 according to the input voltage Vin and the third reference voltage VREF3, thereby controlling the on and off of the load branch 120. For example, the third reference voltage VREF3 may be set to a voltage value interval related to the operating voltage V _LED, when the input voltage Vin is greater than the third reference voltage VREF3, the third transistor MOS3 is controlled to be turned on to turn on the load branch 120 when the load branch 120 can operate normally, the load component LEDn is turned on to operate, when the input voltage Vin is less than or equal to the third reference voltage VREF3, the third transistor MOS3 is controlled to be turned off, when the input voltage Vin decreases to be unable to operate normally, the input current Iin decreases from the maximum value, the discharge current If can be compensated by the load component LEDn, so that the current flowing through the load component LEDn does not decrease immediately, and the load component LEDn can continue to operate, thereby reducing the interruption time and current ripple of the current on the load branch 120 and prolonging the on time of the load branch 120.

For example, the first transistor MOS1, the second transistor MOS2 and the third transistor MOS3 may be configured as multiple types of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor, metal-Oxide semiconductor field effect transistors), and only one possible embodiment of the first transistor MOS1, the second transistor MOS2 and the third transistor MOS3 being N-type MOS transistors is shown in fig. 2, and the other types of transistor structures will not be described again.

Optionally, since the input voltage Vin may vary periodically, the charging and discharging branch 110 may further include: the first linear compensation component con2, the first linear compensation component con2 is connected to the second comparator EA2. The first linear compensation component con2 can reduce the second reference voltage VREF2 under the condition that the input voltage Vin increases, so as to stabilize the power of each component in the charge-discharge branch 110 and reduce the adverse effect of power variation on the component.

Optionally, since the input voltage Vin may vary periodically, the load branch 120 may further include: the second linear compensation component con3, the second linear compensation component con3 is connected to the third comparator EA3. The second linear compensation component con3 can reduce the third reference voltage VREF3 under the condition that the input voltage Vin increases, so as to stabilize the power of each component in the load branch 120 and reduce the adverse effect of the power variation on the component.

The first linear compensation component con2 and the second linear compensation component con3 may be two functional interfaces in the same linear compensation component, or may be two separate devices, for example.

Optionally, to further reduce the current ripple of the load assembly LEDn, the load branch 120 may further comprise: and the ripple removing component is connected with the load component LEDn.

The ripple removing component may further be connected to the second linear compensation component con3, where the ripple removing component may include a capacitor component C2 and a ripple removing chip, where the ripple removing chip is connected to the load component LEDn, and the capacitor component C2 is disposed at two ends of the load component LEDn and the ripple removing chip, and forms a complete ripple removing component, so as to reduce the interruption condition of the current flowing through the load component LEDn, and make the current waveform flowing through the load component LEDn approach to a stable straight line state, thereby reducing the ripple condition of the current and improving the stability of the illumination of the load component LEDn.

In addition, the components in the embodiments of the present application may be integrated together to form a single part, or the components may exist separately, or two or more components may be integrated to form a single part.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, article or apparatus that comprises the element.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus may be implemented in other manners. The apparatus embodiments described above are merely illustrative, for example, block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of devices according to various embodiments of the present application. In this regard, each block in the block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams, and combinations of blocks in the block diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Claims

1. A dimming circuit, the circuit comprising: the device comprises a dimmer, a rectifier bridge, a charge-discharge branch and a load branch;

2. The circuit of claim 1, wherein the circuit further comprises: a dimmer current bias branch; the dimmer current bias branch is connected with the rectifier bridge;

3. The circuit of claim 2, wherein the rectifier bridge is configured to input the input current output by the dimmer into the dimmer current bias branch when the dimmer is on and the input voltage is below the operating voltage of the load branch; the dimmer current bias branch is operable to maintain the dimmer on based on the input current.

4. The circuit of claim 2, wherein the dimmer current bias branch comprises: a first transistor and a first comparator;

5. The circuit of claim 4, wherein the dimmer current bias branch further comprises: an energy-saving controller;

6. The circuit of any one of claims 1-5, wherein the charge-discharge leg comprises: the first diode, the charge-discharge assembly, the second diode, the second transistor and the second comparator;

7. The circuit of claim 6, wherein the charge-discharge leg further comprises: a first linear compensation assembly; the first linear compensation component is connected with the second comparator;

8. The circuit of any of claims 1-5, wherein the load branch comprises: a third transistor, a third comparator, and at least one load component;

9. The circuit of claim 8, wherein the load branch further comprises: a second linear compensation assembly; the second linear compensation component is connected with the third comparator;

10. The circuit of claim 8, wherein the load branch further comprises: a ripple removing component; the ripple removing component is connected with the load component;

11. A lighting system comprising the dimming circuit of any one of claims 1-10.