LED power supply isolation dimming circuit

Abstract

The utility model provides an LED power supply isolation dimming circuit. A dimming input assembly is connected with one end of a first coil of a transformer; the other end of the transformer first coil is grounded; the signal generation assembly is connected with one end of a second coil of the transformer and the dimming output assembly; the other end of the transformer second coil is grounded; an output signal of the signal generation assembly is transmitted to the dimming output assembly and a second coil of the transformer; an output signal of the dimming output assembly is transmitted to the LED lamp; when dimming is carried out, a dimming input signal is transmitted to the dimming input assembly, and a voltage change signal of the dimming input assembly is transmitted to the dimming output assembly through the transformer, so that an output signal of the dimming output assembly is changed. According to the LED power supply dimming circuit, the problem that an existing LED power supply dimming circuit is poor in safety and anti-interference performance is solved, and the effects that the dimming circuit is separated from the main circuit, so that isolated dimming is carried out, and the safety and anti-interference performance of the dimming circuit are improved are achieved.

Description

Technical Field

[0001] This application relates to the field of lighting technology, and in particular to an LED power isolation dimming circuit. Background Technology

[0002] LED lights convert light energy based on the principle of semiconductor electroluminescence, and their brightness can be adjusted through dimming technology.

[0003] LED dimming technology is mainly divided into two categories: direct control and pulse modulation. Direct control, such as analog dimming, achieves dimming by adjusting the constant current chip to change the LED drive current or voltage; pulse modulation, such as PWM pulse width modulation, achieves dimming by controlling the duty cycle of the conduction time through high-frequency switching to maintain the LED in a state of full current or zero current switching.

[0004] However, existing LED power dimming circuits have weak safety and anti-interference capabilities. Utility Model Content

[0005] In view of the above problems, this application is made in order to provide an LED power isolation dimming circuit that overcomes or at least partially solves the above problems.

[0006] This application discloses an LED power isolation dimming circuit, including: a signal generation component, a dimming input component, a dimming output component, and a transformer T1;

[0007] The dimming input component is connected to one end of the first coil of the transformer T1; the other end of the first coil of the transformer T1 is grounded; the signal generating component is connected to one end of the second coil of the transformer T1 and the dimming output component; the other end of the second coil of the transformer T1 is grounded.

[0008] When lighting is applied, the output signal of the signal generating component is transmitted to the dimming output component and the second coil of the transformer T1; the output signal of the dimming output component is transmitted to the LED lamp.

[0009] When dimming is performed, the dimming input signal Vi is transmitted to the dimming input component, and the voltage change signal of the dimming input component is transmitted to the dimming output component through the transformer T1, causing the output signal of the dimming output component to change.

[0010] Furthermore, it includes: a lights-off signal component;

[0011] The light-off signal component is connected to the dimming output component;

[0012] When dimming is performed, the output feedback signal of the dimming output component is transmitted to the light-off signal component;

[0013] When the output feedback signal is lower than a preset threshold, the shutdown control signal of the light-off signal component is transmitted to the LED lamp.

[0014] Furthermore, it includes: rectifier filter components;

[0015] The dimming input component is connected to one end of the first coil of the transformer T1 through the rectifier and filter component;

[0016] When dimming is performed, the voltage change signal of the dimming input component is transmitted to the rectifier and filter component; the current of the rectifier and filter component is transmitted to the first coil of the transformer T1.

[0017] Furthermore, it includes: resistor RL;

[0018] One end of the resistor RL is connected to the dimming input component and the rectifier filter component; the other end of the resistor RL is grounded.

[0019] When the dimming input signal Vi is 0, the output current of the signal generating component is transmitted to the resistor RL through the transformer T1.

[0020] Furthermore, the dimming input component includes: operational amplifier U4A and operational amplifier U4B;

[0021] The non-inverting input terminal of the operational amplifier U4A is connected to one end of resistor R22; the other end of resistor R22 is connected to one end of resistor R18; the other end of resistor R18 is connected to one end of resistor R19 and the +12V power supply; the other end of resistor R19 is connected to the negative terminal of diode D5; the dimming input signal Vi is transmitted to the positive terminal of diode D5.

[0022] The inverting input terminal of the operational amplifier U4A is connected to one end of resistor R24 ​​and one end of resistor R25; the other end of resistor R25 is grounded.

[0023] The output terminal of the operational amplifier U4A is connected to the other end of resistor R24 ​​and one end of resistor R23; one end of resistor R23 is connected to one end of resistor R14 and one end of resistor R15; the dimming input signal Vi is transmitted to the other end of resistor R15.

[0024] The non-inverting input terminal of the operational amplifier U4B is connected to the other end of the resistor R14;

[0025] The inverting input terminal of the operational amplifier U4B is connected to the negative terminal of the diode D2;

[0026] The output terminal of the operational amplifier U4B is connected to the positive terminal of the diode D2 and one end of the first coil of the transformer T1.

[0027] Furthermore, the dimming input component includes: a voltage regulator U2;

[0028] The first terminal of the voltage regulator U2 is connected to the second terminal of the voltage regulator U2, one end of the resistor R18, and one end of the capacitor C18;

[0029] The third terminal of the voltage regulator U2 is connected to the other end of capacitor C18, one end of capacitor C2, and ground; the other end of capacitor C2 is connected to the other end of resistor R18.

[0030] Furthermore, the dimming output component includes: an operational amplifier U3B;

[0031] The non-inverting input terminal of the operational amplifier U3B is connected to one end of resistor R5; the other end of resistor R5 is connected to the anode of Zener diode Z2; the cathode of Zener diode Z2 is connected to the cathode of diode D4; the anode of diode D4 is connected to one end of resistor R16; and the other end of resistor R16 is connected to one end of the second coil of transformer T1.

[0032] The inverting input terminal of the operational amplifier U3B is connected to the negative terminal of diode D3, one end of capacitor C12, and one end of resistor R13; the other end of resistor R13 is connected to one end of resistor R12; the other end of resistor R12 is connected to the other end of capacitor C12 and ground.

[0033] The output terminal of the operational amplifier U3B is connected to the positive terminal of the diode D3;

[0034] When lighting is applied, the output signal at the other end of the resistor R13 is transmitted to the LED lamp.

[0035] Furthermore, the light-off signal component includes: an operational amplifier U3A;

[0036] The non-inverting input terminal of the operational amplifier U3A is connected to one end of the resistor R8; the other end of the resistor R8 is connected to the dimming output component.

[0037] The inverting input terminal of the operational amplifier U3A is connected to one end of resistor R6 and one end of resistor R7; the other end of resistor R6 is grounded; the other end of resistor R7 is connected to one end of resistor R2; the other end of resistor R2 is connected to the +12V power supply.

[0038] When dimming is performed, the output feedback signal of the dimming output component is transmitted to the non-inverting input terminal of the operational amplifier U3A;

[0039] When the output feedback signal is lower than a preset threshold, the shutdown control signal at the output of the operational amplifier U3A is transmitted to the LED lamp.

[0040] Furthermore, the signal generating component includes: chip U5;

[0041] The V+ pin of chip U5 is connected to one end of resistor R11 and the collector of transistor Q2; the other end of resistor R11 is connected to the +12V power supply.

[0042] The O pin of the chip U5 is connected to the base of transistor Q2 and the base of transistor Q3; the collector of transistor Q3 is grounded; the emitter of transistor Q2 is connected to the emitter of transistor Q3 and one end of resistor R20; the other end of resistor R20 is connected to one end of capacitor C17; the other end of capacitor C17 is connected to one end of the second coil of transformer T1 and the dimming output component.

[0043] Furthermore, the rectifier filter component includes: diode D1;

[0044] The positive terminal of the diode D1 is connected to one end of the first coil of the transformer T1;

[0045] The negative terminal of diode D1 is connected to the collector of transistor Q1, one end of capacitor C1, and one end of resistor R3; the base of transistor Q1 is connected to the other end of capacitor C1, one end of capacitor C11, and one end of resistor R9; the collector of transistor Q1 is connected to the other end of capacitor C11, the other end of resistor R9, and the other end of the first coil of transformer T1; the other end of resistor R3 is connected to the dimming input component.

[0046] This application has the following advantages:

[0047] In the embodiments of this application, addressing the weak security and anti-interference capabilities of existing LED power dimming circuits, this application provides a solution for isolated dimming by separating the dimming circuit from the main circuit using a transformer. Specifically, an LED power isolated dimming circuit includes: a signal generating component, a dimming input component, a dimming output component, and a transformer T1; the dimming input component is connected to one end of the first coil of the transformer T1; the other end of the first coil of the transformer T1 is grounded; the signal generating component is connected to one end of the second coil of the transformer T1 and the dimming output component; the other end of the second coil of the transformer T1 is grounded; when lighting is applied, the output signal of the signal generating component is transmitted to the dimming output component and the second coil of the transformer T1; the output signal of the dimming output component is transmitted to the LED lamp; when dimming is applied, the dimming input signal Vi is transmitted to the dimming input component, and the voltage change signal of the dimming input component is transmitted to the dimming output component through the transformer T1, causing a change in the output signal of the dimming output component. This application transmits the voltage change signal to the dimming output component through the transformer T1 and causes the output signal to change, which solves the technical problem of weak safety and anti-interference of existing LED power dimming circuits. It achieves the separation of the dimming circuit from the main circuit, thereby performing isolated dimming and improving the safety and anti-interference of the dimming circuit. Attached Figure Description

[0048] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a structural block diagram of an LED power isolation dimming circuit provided in one embodiment of this application;

[0050] Figure 2 This is a schematic diagram of the overall structure of an LED power isolation dimming circuit according to an embodiment of this application;

[0051] Figure 3 This is a schematic diagram of the circuit structure of the dimming input component in one embodiment of this application;

[0052] Figure 4 This is a schematic diagram of the circuit structure of the dimming output component in one embodiment of this application;

[0053] Figure 5 This is a schematic diagram of the circuit structure of the light-off signal component in one embodiment of this application;

[0054] Figure 6This is a schematic diagram of the circuit structure of a signal generating component in one embodiment of this application;

[0055] Figure 7 This is a schematic diagram of the circuit structure of the rectifier filter component in one embodiment of this application. Detailed Implementation

[0056] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0057] Through analysis of existing technologies, the inventors discovered that separating the dimming signal from the main circuit using electrical isolation technology in LED power supply dimming circuits can improve circuit safety and anti-interference capabilities. From a safety perspective, dimming isolation prevents high voltage in the dimming control circuit from entering low voltage parts accessible to the human body in the event of a malfunction, thus preventing electric shock hazards. For example, in humid environments or scenarios where lamps are installed at low positions, this isolation can better protect user safety. From an anti-interference perspective, the dimming signal line may be subject to external electromagnetic interference. Using isolation technology can reduce the impact of this interference on the power supply and also prevent internal interference from the power supply from being conducted to the dimming control signal line, ensuring the accuracy and stability of the dimming signal and making the dimming effect of LED lights smoother and more precise.

[0058] Based on the above analysis, one of the core technical concepts of this application is to separate the dimming circuit from the main circuit through a transformer, thereby achieving isolated dimming.

[0059] It should be noted that, in any embodiment of this application, the LED power supply isolation dimming circuit of this application can be applied to lighting switching power supplies as an isolation dimming interface module to achieve 0~10V, PWM, and resistor-based three-in-one isolation dimming. It can also be applied to other products that require both safety isolation and adjustment of circuit current or voltage.

[0060] Reference Figure 1 This illustration shows an LED power isolation dimming circuit according to an embodiment of the present application, including: a signal generating component, a dimming input component, a dimming output component, and a transformer T1;

[0061] The dimming input component is connected to one end of the first coil of the transformer T1; the other end of the first coil of the transformer T1 is grounded; the signal generating component is connected to one end of the second coil of the transformer T1 and the dimming output component; the other end of the second coil of the transformer T1 is grounded.

[0062] When lighting is applied, the output signal of the signal generating component is transmitted to the dimming output component and the second coil of the transformer T1; the output signal of the dimming output component is transmitted to the LED lamp.

[0063] When dimming is performed, the dimming input signal Vi is transmitted to the dimming input component, and the voltage change signal of the dimming input component is transmitted to the dimming output component through the transformer T1, causing the output signal of the dimming output component to change.

[0064] In the embodiments of this application, addressing the weak security and anti-interference capabilities of existing LED power dimming circuits, this application provides a solution for isolated dimming by separating the dimming circuit from the main circuit using a transformer. Specifically, an LED power isolated dimming circuit includes: a signal generating component, a dimming input component, a dimming output component, and a transformer T1; the dimming input component is connected to one end of the first coil of the transformer T1; the other end of the first coil of the transformer T1 is grounded; the signal generating component is connected to one end of the second coil of the transformer T1 and the dimming output component; the other end of the second coil of the transformer T1 is grounded; when lighting is applied, the output signal of the signal generating component is transmitted to the dimming output component and the second coil of the transformer T1; the output signal of the dimming output component is transmitted to the LED lamp; when dimming is applied, the dimming input signal Vi is transmitted to the dimming input component, and the voltage change signal of the dimming input component is transmitted to the dimming output component through the transformer T1, causing a change in the output signal of the dimming output component. This application transmits the voltage change signal to the dimming output component through the transformer T1 and causes the output signal to change, which solves the technical problem of weak safety and anti-interference of existing LED power dimming circuits. It achieves the separation of the dimming circuit from the main circuit, thereby performing isolated dimming and improving the safety and anti-interference of the dimming circuit.

[0065] The following will further describe an LED power isolation dimming circuit in this exemplary embodiment.

[0066] It should be noted that the signal generation component generates a voltage Vp in the second coil of transformer T1. The voltage Vp is coupled to the first coil of transformer T1 to generate a voltage Vs. The voltage Vp is also processed by the dimming output component and converted into an output reference voltage VREF. When lighting is applied, the voltage VREF is output to the LED lamp at its maximum value.

[0067] The dimming input signal Vi can be a PWM signal or a 0~10V signal; when dimming, there are two possibilities: the dimming input signal Vi can decrease or increase.

[0068] If the dimming input signal Vi continues to decrease, the dimming input signal Vi will generate a decreasing analog voltage after being converted by the dimming input component. This analog voltage will pull down the voltage Vs, and the decrease in voltage Vs will inevitably lead to a decrease in voltage Vp, which in turn will cause a decrease in the output signal VREF of the dimming output component.

[0069] If the dimming input signal Vi continues to increase, the dimming input signal Vi will generate an increased analog voltage after being converted by the dimming input component. This analog voltage will raise the voltage Vs, and the increase in voltage Vs will inevitably lead to an increase in voltage Vp, which in turn will cause the output signal VREF of the dimming output component to increase.

[0070] Reference Figure 1 In one embodiment of this application, it includes: a light-off signal component;

[0071] The light-off signal component is connected to the dimming output component;

[0072] When dimming is performed, the output feedback signal of the dimming output component is transmitted to the light-off signal component;

[0073] When the output feedback signal is lower than a preset threshold, the shutdown control signal of the light-off signal component is transmitted to the LED lamp.

[0074] It should be noted that the circuit output of this embodiment has two paths: one is the reference voltage VREF, and the other is the signal VO-OFF that turns off the main output.

[0075] As an example, the output feedback signal can be the output signal VREF of the dimming output component. When the dimming output component detects that the output signal VREF of the dimming output component is lower than a certain value, the off control signal VO-OFF of the light-off signal component is low to turn off the output; when the dimming output component detects that the output signal VREF of the dimming output component is higher than a certain value, the output signal VO-OFF of the dimming output component is high to turn on the output.

[0076] Reference Figure 1 In one embodiment of this application, it includes: a rectifier filter component;

[0077] The dimming input component is connected to one end of the first coil of the transformer T1 through the rectifier and filter component;

[0078] When dimming is performed, the voltage change signal of the dimming input component is transmitted to the rectifier and filter component; the current of the rectifier and filter component is transmitted to the first coil of the transformer T1.

[0079] It should be noted that the rectifier and filter component can perform rectification and filtering on the voltage Vs.

[0080] Reference Figure 1 In one embodiment of this application, it includes: a resistor RL;

[0081] One end of the resistor RL is connected to the dimming input component and the rectifier filter component; the other end of the resistor RL is grounded.

[0082] When the dimming input signal Vi is 0, the output current of the signal generating component is transmitted to the resistor RL through the transformer T1.

[0083] It should be noted that when resistor RL is present, the voltage Vs, after being processed by the rectifier and filter components, forms voltage VRL. If there is no signal input at the input terminal of the dimming input component, the entire voltage VRL is consumed by resistor RL. During dimming, there are two possibilities: the dimming input signal Vi decreases or increases.

[0084] If the dimming input signal Vi continues to decrease, the dimming input signal Vi will generate a decreasing analog voltage after being converted by the dimming input component. This analog voltage will lower VRL and thus lower the voltage Vs. The decrease in voltage Vs will inevitably lead to a decrease in voltage Vp, which in turn will cause a decrease in the output signal VREF of the dimming output component.

[0085] If the dimming input signal Vi continues to increase, the dimming input signal Vi will generate an increased analog voltage after being converted by the dimming input component. This analog voltage will raise VRL and thus raise the voltage Vs. The increase in voltage Vs will inevitably lead to an increase in voltage Vp, which in turn will cause the output signal VREF of the dimming output component to increase.

[0086] exist Figure 1 Based on the structural block diagram Figure 2 This illustration shows a specific circuit structure diagram of an LED power isolation dimming circuit according to an embodiment of this application. It is understood that... Figure 3-7 The following are specific examples. Figure 2 A partial circuit diagram of the corresponding component in the circuit.

[0087] Reference Figure 3 In one embodiment of this application, the dimming input component includes: operational amplifier U4A and operational amplifier U4B;

[0088] The non-inverting input terminal of the operational amplifier U4A is connected to one end of resistor R22; the other end of resistor R22 is connected to one end of resistor R18; the other end of resistor R18 is connected to one end of resistor R19 and the +12V power supply; the other end of resistor R19 is connected to the negative terminal of diode D5; the dimming input signal Vi is transmitted to the positive terminal of diode D5.

[0089] The inverting input terminal of the operational amplifier U4A is connected to one end of resistor R24 ​​and one end of resistor R25; the other end of resistor R25 is grounded.

[0090] The output terminal of the operational amplifier U4A is connected to the other end of resistor R24 ​​and one end of resistor R23; one end of resistor R23 is connected to one end of resistor R14 and one end of resistor R15; the dimming input signal Vi is transmitted to the other end of resistor R15.

[0091] The non-inverting input terminal of the operational amplifier U4B is connected to the other end of the resistor R14;

[0092] The inverting input terminal of the operational amplifier U4B is connected to the negative terminal of the diode D2;

[0093] The output terminal of the operational amplifier U4B is connected to the positive terminal of the diode D2 and one end of the first coil of the transformer T1.

[0094] It should be noted that the dimming input signal Vi can be a PWM signal or a 0~10V signal, and the dimming input signal Vi is input from DIM+. When the dimming input signal Vi is unconnected, the operational amplifier U4A and its peripheral components can form a full-load output circuit. The operational amplifier U4B and its peripheral components can form a 0-10V input follower circuit.

[0095] Reference Figure 3 In one embodiment of this application, the dimming input component includes: a voltage regulator U2;

[0096] The first terminal of the voltage regulator U2 is connected to the second terminal of the voltage regulator U2, one end of the resistor R18, and one end of the capacitor C18;

[0097] The third terminal of the voltage regulator U2 is connected to the other end of capacitor C18, one end of capacitor C2, and ground; the other end of capacitor C2 is connected to the other end of resistor R18.

[0098] Reference Figure 4 In one embodiment of this application, the dimming output component includes: an operational amplifier U3B;

[0099] The non-inverting input terminal of the operational amplifier U3B is connected to one end of resistor R5; the other end of resistor R5 is connected to the anode of Zener diode Z2; the cathode of Zener diode Z2 is connected to the cathode of diode D4; the anode of diode D4 is connected to one end of resistor R16; and the other end of resistor R16 is connected to one end of the second coil of transformer T1.

[0100] The inverting input terminal of the operational amplifier U3B is connected to the negative terminal of diode D3, one end of capacitor C12, and one end of resistor R13; the other end of resistor R13 is connected to one end of resistor R12; the other end of resistor R12 is connected to the other end of capacitor C12 and ground.

[0101] The output terminal of the operational amplifier U3B is connected to the positive terminal of the diode D3;

[0102] When lighting is applied, the output signal at the other end of the resistor R13 is transmitted to the LED lamp.

[0103] Reference Figure 5 In one embodiment of this application, the light-off signal component includes: an operational amplifier U3A;

[0104] The non-inverting input terminal of the operational amplifier U3A is connected to one end of the resistor R8; the other end of the resistor R8 is connected to the dimming output component.

[0105] The inverting input terminal of the operational amplifier U3A is connected to one end of resistor R6 and one end of resistor R7; the other end of resistor R6 is grounded; the other end of resistor R7 is connected to one end of resistor R2; the other end of resistor R2 is connected to the +12V power supply.

[0106] When dimming is performed, the output feedback signal of the dimming output component is transmitted to the non-inverting input terminal of the operational amplifier U3A;

[0107] When the output feedback signal is lower than a preset threshold, the shutdown control signal at the output of the operational amplifier U3A is transmitted to the LED lamp.

[0108] In one specific embodiment of this application, it further includes: a voltage regulator U1;

[0109] The first terminal of the voltage regulator U1 is connected to the second terminal of the voltage regulator U1, one end of the resistor R2 and one end of the capacitor C5;

[0110] The third terminal of the voltage regulator U1 is connected to the other terminal of the capacitor C5 and the ground wire.

[0111] Reference Figure 6 In one embodiment of this application, the signal generating component includes: chip U5;

[0112] The V+ pin of chip U5 is connected to one end of resistor R11 and the collector of transistor Q2; the other end of resistor R11 is connected to the +12V power supply.

[0113] The O pin of the chip U5 is connected to the base of transistor Q2 and the base of transistor Q3; the collector of transistor Q3 is grounded; the emitter of transistor Q2 is connected to the emitter of transistor Q3 and one end of resistor R20; the other end of resistor R20 is connected to one end of capacitor C17; the other end of capacitor C17 is connected to one end of the second coil of transformer T1 and the dimming output component.

[0114] It should be noted that the chip U5 can be a 555D. The chip U5 and its peripheral components can form a PWM signal generator. After being current-limited by resistor R20 and isolated by capacitor C17, the DC signal enters the second coil of transformer T1 and generates an induced voltage VP.

[0115] Reference Figure 7 In one embodiment of this application, the rectifier filter component includes: diode D1;

[0116] The positive terminal of the diode D1 is connected to one end of the first coil of the transformer T1;

[0117] The negative terminal of diode D1 is connected to the collector of transistor Q1, one end of capacitor C1, and one end of resistor R3; the base of transistor Q1 is connected to the other end of capacitor C1, one end of capacitor C11, and one end of resistor R9; the collector of transistor Q1 is connected to the other end of capacitor C11, the other end of resistor R9, and the other end of the first coil of transformer T1; the other end of resistor R3 is connected to the dimming input component.

[0118] It should be noted that the voltage VRL can be the voltage at the negative terminal of diode D1. If there is no signal input at the input terminal of the dimming input component, the entire voltage VRL will be consumed by transistor Q1.

[0119] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0120] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0121] The above provides a detailed description of an LED power isolation dimming circuit. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, those skilled in the art will recognize that there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An LED power-isolated dimming circuit, characterized in that, include: Signal generating component, dimming input component, dimming output component, and transformer T1; The dimming input component is connected to one end of the first coil of the transformer T1; the other end of the first coil of the transformer T1 is grounded; the signal generating component is connected to one end of the second coil of the transformer T1 and the dimming output component; the other end of the second coil of the transformer T1 is grounded. When lighting is applied, the output signal of the signal generating component is transmitted to the dimming output component and the second coil of the transformer T1; the output signal of the dimming output component is transmitted to the LED lamp. When dimming is performed, the dimming input signal Vi is transmitted to the dimming input component, and the voltage change signal of the dimming input component is transmitted to the dimming output component through the transformer T1, causing the output signal of the dimming output component to change.

2. The LED power isolation dimming circuit according to claim 1, characterized in that, include: Lights-off signal component; The light-off signal component is connected to the dimming output component; When dimming is performed, the output feedback signal of the dimming output component is transmitted to the light-off signal component; When the output feedback signal is lower than a preset threshold, the shutdown control signal of the light-off signal component is transmitted to the LED lamp.

3. The LED power isolation dimming circuit according to claim 1, characterized in that, include: Rectifier filter components; The dimming input component is connected to one end of the first coil of the transformer T1 through the rectifier and filter component; When dimming is performed, the voltage change signal of the dimming input component is transmitted to the rectifier and filter component; the current of the rectifier and filter component is transmitted to the first coil of the transformer T1.

4. The LED power isolation dimming circuit according to claim 3, characterized in that, include: Resistance RL; One end of the resistor RL is connected to the dimming input component and the rectifier filter component; The other end of the resistor RL is grounded; When the dimming input signal Vi is 0, the output current of the signal generating component is transmitted to the resistor RL through the transformer T1.

5. The LED power isolation dimming circuit according to claim 1, characterized in that, The dimming input component includes: operational amplifier U4A and operational amplifier U4B; The non-inverting input terminal of the operational amplifier U4A is connected to one end of resistor R22; the other end of resistor R22 is connected to one end of resistor R18; the other end of resistor R18 is connected to one end of resistor R19 and the +12V power supply; the other end of resistor R19 is connected to the negative terminal of diode D5; the dimming input signal Vi is transmitted to the positive terminal of diode D5. The inverting input terminal of the operational amplifier U4A is connected to one end of resistor R24 ​​and one end of resistor R25; the other end of resistor R25 is grounded. The output terminal of the operational amplifier U4A is connected to the other end of resistor R24 ​​and one end of resistor R23; one end of resistor R23 is connected to one end of resistor R14 and one end of resistor R15; the dimming input signal Vi is transmitted to the other end of resistor R15. The non-inverting input terminal of the operational amplifier U4B is connected to the other end of the resistor R14; The inverting input terminal of the operational amplifier U4B is connected to the negative terminal of the diode D2; The output terminal of the operational amplifier U4B is connected to the positive terminal of the diode D2 and one end of the first coil of the transformer T1.

6. The LED power isolation dimming circuit according to claim 5, characterized in that, The dimming input component includes: a voltage regulator U2; The first terminal of the voltage regulator U2 is connected to the second terminal of the voltage regulator U2, one end of the resistor R18, and one end of the capacitor C18; The third terminal of the voltage regulator U2 is connected to the other end of capacitor C18, one end of capacitor C2, and ground; the other end of capacitor C2 is connected to the other end of resistor R18.

7. The LED power isolation dimming circuit according to claim 1, characterized in that, The dimming output component includes: operational amplifier U3B; The non-inverting input terminal of the operational amplifier U3B is connected to one end of resistor R5; the other end of resistor R5 is connected to the anode of Zener diode Z2; the cathode of Zener diode Z2 is connected to the cathode of diode D4; the anode of diode D4 is connected to one end of resistor R16; and the other end of resistor R16 is connected to one end of the second coil of transformer T1. The inverting input terminal of the operational amplifier U3B is connected to the negative terminal of diode D3, one end of capacitor C12, and one end of resistor R13; the other end of resistor R13 is connected to one end of resistor R12; the other end of resistor R12 is connected to the other end of capacitor C12 and ground. The output terminal of the operational amplifier U3B is connected to the positive terminal of the diode D3; When lighting is applied, the output signal at the other end of the resistor R13 is transmitted to the LED lamp.

8. The LED power isolation dimming circuit according to claim 2, characterized in that, The light-off signal component includes: operational amplifier U3A; The non-inverting input terminal of the operational amplifier U3A is connected to one end of the resistor R8; the other end of the resistor R8 is connected to the dimming output component. The inverting input terminal of the operational amplifier U3A is connected to one end of resistor R6 and one end of resistor R7; the other end of resistor R6 is grounded; the other end of resistor R7 is connected to one end of resistor R2; the other end of resistor R2 is connected to the +12V power supply. When dimming is performed, the output feedback signal of the dimming output component is transmitted to the non-inverting input terminal of the operational amplifier U3A; When the output feedback signal is lower than a preset threshold, the shutdown control signal at the output of the operational amplifier U3A is transmitted to the LED lamp.

9. The LED power isolation dimming circuit according to claim 1, characterized in that, The signal generating component includes: chip U5; The V+ pin of chip U5 is connected to one end of resistor R11 and the collector of transistor Q2; the other end of resistor R11 is connected to the +12V power supply. The O pin of the chip U5 is connected to the base of transistor Q2 and the base of transistor Q3; the collector of transistor Q3 is grounded; the emitter of transistor Q2 is connected to the emitter of transistor Q3 and one end of resistor R20; the other end of resistor R20 is connected to one end of capacitor C17; the other end of capacitor C17 is connected to one end of the second coil of transformer T1 and the dimming output component.

10. The LED power isolation dimming circuit according to claim 3, characterized in that, The rectifier filter component includes: diode D1; The positive terminal of the diode D1 is connected to one end of the first coil of the transformer T1; The negative terminal of diode D1 is connected to the collector of transistor Q1, one end of capacitor C1, and one end of resistor R3; the base of transistor Q1 is connected to the other end of capacitor C1, one end of capacitor C11, and one end of resistor R9; the collector of transistor Q1 is connected to the other end of capacitor C11, the other end of resistor R9, and the other end of the first coil of transformer T1; the other end of resistor R3 is connected to the dimming input component.

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