Multi-section dimming circuit and LED lamp

Abstract

The invention provides a multi-section dimming circuit and an LED lamp. The multi-section dimming circuit is used for an LED lamp and comprises an IC chip and a voltage regulating module. The IC chip comprises a dimming port and a pulse width modulation output port; the input end of the voltage regulating module is connected with the power supply, and the output end is connected with the dimming control port; wherein the voltage regulating module comprises a reference voltage dividing unit and at least one regulating resistor unit; adjusting the total resistance value of the voltage adjusting module based on the adjusting resistance value of the adjusting resistance unit; adjusting the dimming voltage input into the dimming control port based on the total resistance value; and the IC chip controls the pulse width modulation output port to output a pulse signal with a corresponding width based on the dimming voltage so as to adjust the brightness of the LED lamp. By adjusting the resistance value of the voltage adjusting module, the dimming voltage of the dimming port is accurately controlled, and multi-section dimming is carried out; and the resistance value of the voltage regulating module is above the preset resistance threshold value, so that the voltage regulating circuit is prevented from being influenced by circuit fluctuation, and the stability and the accuracy of the dimming circuit are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of dimming circuits, and in particular to a multi-stage dimming circuit and an LED lamp. Background Art

[0002] In the field of dimming circuit technology for LED lamps, the implementation of dimming usually involves fine control of key components in the circuit. Especially in the application of dimming resistors, its working principle and potential problems are worth in-depth discussion.

[0003] The role of the dimming resistor in the dimming circuit is to adjust the current in the circuit by changing its resistance value, thereby achieving control of the LED brightness. This dimming method is called analog dimming or linear dimming. It changes the resistance value in the circuit by adjusting the potentiometer, thereby controlling the output current or voltage of the driving circuit, thereby achieving adjustment of the brightness of the light source.

[0004] However, when the resistance of the dimming resistor is small, its performance in the circuit will be affected by the line and the interference is large. In the low resistance state, the dimming resistor is more sensitive to small voltage fluctuations in the circuit. These fluctuations may come from the instability of the power supply, noise in the circuit or interference from other electronic components. In addition, the low resistance dimming resistor may generate a large current in the circuit, which not only increases energy loss, but also may cause thermal problems in the circuit, affecting the life and performance of LED lamps. Summary of the invention

[0005] The technical problem to be solved by the present disclosure is to overcome the defect of low resistance of dimming resistors in the prior art, which leads to susceptibility to interference, and to provide a multi-stage dimming circuit and an LED lamp.

[0006] The present invention solves the above technical problems through the following technical solutions: In a first aspect, a multi-stage dimming circuit is provided for use in an LED lamp, comprising an IC chip and a voltage regulating module; The IC chip includes a dimming port and a pulse width modulation (PWM) output port; The input end of the voltage regulating module is connected to the power supply, and the output end is connected to the dimming control port; Wherein, the voltage regulating module comprises a reference voltage dividing unit and at least one regulating resistance unit; Adjusting the total resistance of the voltage regulating module based on the adjustment resistance of the adjustment resistance unit; adjusting a dimming voltage input to the dimming control port based on the total resistance; The IC chip controls the pulse width modulation output port to output a pulse signal of corresponding width based on the dimming voltage, so as to adjust the brightness of the LED lamp.

[0007] Preferably, the regulating resistance unit is connected in series with the reference voltage dividing unit.

[0008] Preferably, the reference voltage-dividing unit comprises a first voltage-dividing resistor, a second voltage-dividing resistor and a third voltage-dividing resistor; One end of the first voltage-dividing resistor is connected to the power supply, and the other end is connected to one end of the second voltage-dividing resistor; The other end of the second voltage-dividing resistor is connected to the dimming port; One end of the third voltage-dividing resistor is connected to the second voltage-dividing resistor, and the other end of the third resistor is grounded; One end of the regulating resistor unit is connected to one end of the second voltage-dividing resistor, and the other end is grounded.

[0009] Preferably, the voltage regulating module includes at least two regulating resistor units.

[0010] Preferably, the regulating resistance units are connected in parallel.

[0011] Preferably, the regulating resistor unit comprises a regulating resistor and a circuit breaker connected in series; The circuit breaker is used to control the regulating resistor to be connected to the voltage regulating module to adjust the total resistance of the voltage regulating module.

[0012] Preferably, the total resistance of the voltage regulating module is greater than a preset resistance threshold.

[0013] In a second aspect, an LED lamp is provided, comprising the multi-stage dimming circuit described in the first aspect.

[0014] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present disclosure.

[0015] The positive and progressive effects of the present disclosure are: by adjusting the resistance of the voltage regulating module, the dimming voltage of the dimming port is accurately controlled to perform multi-stage dimming; and the resistance of the voltage regulating module is made above a preset resistance threshold, thereby preventing the voltage regulating circuit from being affected by circuit fluctuations and improving the stability and accuracy of the dimming circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the circuit structure of a multi-level dimming circuit provided by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0017] The present disclosure is further described below by way of examples, but the present disclosure is not limited to the scope of the examples.

[0018] Prefixes such as "first" and "second" are used in the embodiments of the present disclosure only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present disclosure does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0019] Example 1 This embodiment provides a multi-stage dimming circuit, such as Figure 1 As shown, it is used for LED lamps, including IC chips and voltage regulating modules; The IC chip includes a dimming port and a pulse width modulation output port; The input end of the voltage regulating module is connected to the power supply, and the output end is connected to the dimming control port; Wherein, the voltage regulating module comprises a reference voltage dividing unit and at least one regulating resistance unit; Adjusting the total resistance of the voltage regulating module based on the adjustment resistance of the adjustment resistance unit; adjusting a dimming voltage input to the dimming control port based on the total resistance; The IC chip controls the pulse width modulation output port to output a pulse signal of corresponding width based on the dimming voltage, so as to adjust the brightness of the LED lamp.

[0020] In this solution, the total resistance value of the voltage regulating module can be adjusted by adjusting the number of adjusting resistor units connected to the voltage regulating module, thereby achieving multi-stage control of the dimming voltage of the input dimming port. The IC chip controls the pulse width modulation output port based on the dimming voltage to output a first pulse signal of corresponding width, thereby achieving multi-level dimming control of the LED lamp.

[0021] In one embodiment, the IC chip also includes a first dimming mode port RS1 and a second dimming mode port RS2 and a dimming mode voltage-dividing resistor RS. The resistance of the dimming mode voltage-dividing resistor RS changes, so that the first dimming mode port RS1 or the second dimming mode port RS2 generates a high-level signal. Based on the high-level signal corresponding to the first dimming mode port RS1 or the second dimming mode port RS2, the IC chip controls the pulse width modulation output port to output a second pulse signal of corresponding width, thereby realizing mode switching control of the LED lamp.

[0022] As an implementable manner, the regulating resistance unit is connected in series with the reference voltage dividing unit.

[0023] In this solution, by incorporating the adjustment resistor unit into the series circuit with the reference voltage divider unit, the total resistance of the voltage regulator module is gradually increased by the variable adjustment resistor unit, and the voltage of the DIM port can be flexibly adjusted, thereby achieving fine control of the light brightness.

[0024] As an implementable manner, the reference voltage dividing unit includes a first voltage dividing resistor RX1, a second voltage dividing resistor RX2 and a third voltage dividing resistor RX3; One end of the first voltage-dividing resistor RX1 is connected to the power supply, and the other end is connected to one end of the second voltage-dividing resistor RX2; The other end of the second voltage-dividing resistor RX2 is connected to the dimming port; One end of the third voltage-dividing resistor RX3 is connected to the second voltage-dividing resistor RX2, and the other end of the third resistor RX3 is grounded; One end of the regulating resistor unit is connected to one end of the second voltage-dividing resistor RX2, and the other end is grounded.

[0025] In this solution, the first voltage-dividing resistor RX1, the second voltage-dividing resistor RX2 and the third voltage-dividing resistor RX3 serve as reference voltage-dividing units of the voltage regulating module. The voltage regulating module has corresponding reference resistance values ​​based on the reference voltage-dividing units. The reference voltage-dividing units provide a stable reference voltage for the DIM pin of the IC and are used to limit the current flowing through the IC chip to protect the IC chip from being damaged by excessive current.

[0026] As an implementable manner, the voltage regulating module includes at least two regulating resistance units.

[0027] In this solution, the total resistance of the voltage regulating module can be adjusted in multiple levels through at least two adjusting resistance units, and the voltage of the DIM port can be flexibly adjusted, thereby achieving fine control of the light brightness.

[0028] As a feasible manner, the regulating resistance units are connected in parallel.

[0029] In this solution, through the parallel structure between multiple groups of regulating resistor units, different regulating resistor units are made redundant to each other, and by connecting multiple groups of parallel regulating resistor units, the total resistance of the voltage regulating module can be more finely controlled.

[0030] As an achievable manner, the regulating resistor unit includes regulating resistors connected in series and circuit breakers ; The circuit breaker is used to control the regulating resistor to be connected to the voltage regulating module to adjust the total resistance of the voltage regulating module.

[0031] In this solution, the circuit breaker As a switch key control connected to the voltage regulating module, the adjustment resistor reduces the difficulty of control programming with a simple structure. In one embodiment, each adjustment resistor has a different resistance value to correspond to the dimming voltage of the IC chip, and at least one adjustment resistor is an adjustable resistance resistor, which is used as a redundant resistor to ensure the stability of the voltage regulating circuit.

[0032] As an implementable manner, the total resistance of the voltage regulating module is greater than a preset resistance threshold.

[0033] In this solution, the total resistance of the voltage regulating module is increased on the basis of the reference resistance by adjusting the resistance unit, and the total resistance is positively correlated with the line length in the dimming circuit. The preset resistance threshold represents the minimum resistance of the voltage regulating module that can resist interference based on the line length. By controlling the total resistance of the voltage regulating module to be greater than the preset resistance threshold, the stability of the voltage regulating circuit is guaranteed.

[0034] The multi-stage dimming circuit provided in this embodiment performs multi-stage dimming by adjusting the resistance value of the voltage regulating module to accurately control the dimming voltage of the dimming port; and makes the resistance value of the voltage regulating module above the preset resistance threshold to avoid the voltage regulating circuit being affected by circuit fluctuations, thereby improving the stability and accuracy of the dimming circuit.

[0035] Example 2 This embodiment provides an LED lamp, including the multi-stage dimming circuit described in the embodiment.

[0036] The LED lamp provided in this embodiment adjusts the resistance of the voltage regulating module in the dimming circuit to accurately control the dimming voltage of the dimming port to perform multi-stage dimming; and makes the resistance of the voltage regulating module above a preset resistance threshold to avoid the voltage regulating circuit being affected by circuit fluctuations, thereby improving the stability and accuracy of the dimming circuit and realizing multi-level precise dimming of the LED lamp.

[0037] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A multi-stage dimming circuit, characterized in that: Used in LED lamps, including IC chips and voltage regulator modules; The IC chip includes a dimming port and a pulse width modulation output port; The input end of the voltage regulating module is connected to the power supply, and the output end is connected to the dimming control port; Wherein, the voltage regulating module comprises a reference voltage dividing unit and at least one regulating resistance unit; Adjusting the total resistance of the voltage regulating module based on the adjustment resistance of the adjustment resistance unit; adjusting a dimming voltage input to the dimming control port based on the total resistance; The IC chip controls the pulse width modulation output port to output a pulse signal of corresponding width based on the dimming voltage, so as to adjust the brightness of the LED lamp.

2. The multi-stage dimming circuit according to claim 1, characterized in that: The regulating resistance unit is connected in series with the reference voltage dividing unit.

3. The multi-stage dimming circuit according to claim 2, characterized in that: The reference voltage dividing unit includes a first voltage dividing resistor, a second voltage dividing resistor and a third voltage dividing resistor; One end of the first voltage-dividing resistor is connected to the power supply, and the other end is connected to one end of the second voltage-dividing resistor; The other end of the second voltage-dividing resistor is connected to the dimming port; One end of the third voltage-dividing resistor is connected to the second voltage-dividing resistor, and the other end of the third resistor is grounded; One end of the regulating resistor unit is connected to one end of the second voltage-dividing resistor, and the other end is grounded.

4. The multi-stage dimming circuit according to claim 3, characterized in that: The voltage regulating module includes at least two regulating resistor units.

5. The multi-stage dimming circuit according to claim 1, characterized in that: The regulating resistance units are connected in parallel.

6. The multi-stage dimming circuit according to claim 1, characterized in that: The regulating resistor unit includes a regulating resistor and a circuit breaker connected in series; The circuit breaker is used to control the regulating resistor to be connected to the voltage regulating module to adjust the total resistance of the voltage regulating module.

7. The multi-stage dimming circuit according to claim 6, characterized in that: The total resistance of the voltage regulating module is greater than a preset resistance threshold.

8. An LED lamp, characterized in that: The multi-stage dimming circuit comprises the multi-stage dimming circuit as claimed in any one of claims 1 to 7.

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