Light string dimming control circuit

Abstract

The utility model relates to the technical field of light string dimming, and discloses a light string dimming control circuit, which comprises a load circuit and a voltage stabilizing circuit, the load circuit comprises a synchronous step-down driving chip U8, a capacitor C8 is connected between a fifth pin and a sixth pin of the synchronous step-down driving chip U8, and the capacitor C8 is connected with the voltage stabilizing circuit. By means of the design of the load circuit, it is ensured that the lamp string can work stably after being connected into the circuit, the conditions that the lamp string flickers and the brightness is unstable are avoided, the lamp string driving circuit can adapt to different types of loads (a resistor, a capacitor, the inductor and the like), and the service life of the lamp string driving circuit is prolonged. Stable operation of the lamp string under various load conditions is ensured, the fault rate of the lamp string is reduced, and the service life of the lamp string is prolonged; through the design of the voltage stabilizing circuit, the voltage of the lamp string is kept stable within a certain range and is not influenced by input voltage fluctuation and load change, the output voltage can be automatically adjusted, and the lamp string is prevented from being damaged due to abnormal voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of lamp string dimming, and particularly relates to a lamp string dimming control circuit. Background Technique

[0002] Lamp string dimming refers to adjusting the brightness or color of the light sources in the lamp string to meet different lighting requirements or create specific visual effects.

[0003] The brightness adjustment of the lamp string is mainly achieved by controlling the magnitude of the current flowing through the lamp string. The greater the current, the brighter the light emitted by the light source; conversely, the smaller the current, the dimmer the light source.

[0004] The color adjustment of the lamp string is achieved by adjusting the brightness ratio of different color LEDs. By mixing the three primary color lights of red, green, and blue, various colors of light can be produced.

[0005] After retrieval, the patent with the application number CN201922450668.7 discloses a multi-channel LED lamp string dimming control circuit, which combines multiple low-cost LED lamp strings into a low-cost LED light effect landscape system with programmable light effects. The PWM output of the PCA9685 chip is controlled through the I2C bus to drive the LED lamp string, realizing the on, off, and continuous dimming of the lamp string. Through the 16-channel PWM programming of the PCA9685 and the cascade expansion of multiple PCA9685 chips, the light effects of 1 - 1024 low-cost lamp strings can be programmed and controlled.

[0006] The current lamp string lacks a suitable load matching, which affects the operating state of the lamp string. After the lamp string runs for a long time, it is easy to cause problems such as lamp flashing and unstable brightness, thereby increasing the failure rate of the lamp string and reducing the service life of the lamp string. Therefore, we need to propose a lamp string dimming control circuit. Content of the Utility Model

[0007] The purpose of the utility model is to provide a lamp string dimming control circuit. Through the design of the load circuit, it is ensured that the lamp string can work stably after being connected to the circuit, avoiding the situations of lamp string flashing and unstable brightness, and being able to adapt to different types of loads (resistors, capacitors, inductors, etc.), ensuring that the lamp string can operate stably under various load conditions, reducing the failure rate of the lamp string, and improving the service life of the lamp string; through the design of the voltage stabilizing circuit, the lamp string voltage is kept stable within a certain range, not affected by the input voltage fluctuation and load change, and can automatically adjust the output voltage to prevent the lamp string from being damaged due to abnormal voltage, so as to solve the problems raised in the above background technique.

[0008] To achieve the above object, the present utility model provides the following technical solution: A lamp string dimming control circuit, including a load circuit and a voltage stabilizing circuit. The load circuit includes a synchronous buck driving chip U8. A capacitor C8 is connected between the 5th pin and the 6th pin of the synchronous buck driving chip U8. One end of the capacitor C8 is connected to an inductor L1. A series-connected light-emitting diode group is connected between the 1st pin of the synchronous buck driving chip U8 and one end of the inductor L1. The synchronous buck driving chip U8 is provided with a DIM pin for receiving a PWM signal and realizing dimming. Capacitors C7, C12 and C2 which are connected in parallel and grounded are connected between the 3rd pin and the 4th pin of the synchronous buck driving chip U8.

[0009] Preferably, a grounded resistor R1 is connected to the 1st pin of the synchronous buck driving chip U8, and a grounded resistor R3 is connected to the 2nd pin of the synchronous buck driving chip U8.

[0010] Preferably, a grounded capacitor C3 is connected to one end of the inductor L1, and the 4th pin of the synchronous buck driving chip U8 outputs a 20V DC voltage.

[0011] Preferably, the voltage stabilizing circuit includes a voltage stabilizing chip U6. A capacitor C6 is connected between the 1st pin and the 8th pin of the voltage stabilizing chip U6. A grounded diode D2 is also connected to the 8th pin of the voltage stabilizing chip U6. A resistor R34 is connected to the 2nd pin of the voltage stabilizing chip U6. An inductor L3 is connected to the 8th pin of the voltage stabilizing chip U6. The connection terminals of the resistor R34 and the inductor L3 output a 5V voltage.

[0012] Preferably, capacitors C69 and a resistor R104 which are connected in parallel are connected to the 4th pin of the voltage stabilizing chip U6. One connection terminal of the capacitor C69 and the resistor R104 is connected to a grounded resistor R103. The other connection terminal of the capacitor C69 and the resistor R104 is connected to the connection terminal between the resistor R34 and the inductor L3. The other connection terminal of the capacitor C69 and the resistor R104 is connected to a capacitor C1 connected to 5V.

[0013] Preferably, capacitors C74 and C75 which are connected in parallel are connected between the 6th pin and the 7th pin of the voltage stabilizing chip U6. The 5th pin of the voltage stabilizing chip U6 is connected to the 7th pin, and a capacitor C73 is connected to the 5th pin of the voltage stabilizing chip U6. One end of the capacitor C73 is connected to the connection terminal of the capacitors C74 and C75.

[0014] Compared with the prior art, the beneficial effects of the present utility model are:

[0015] Through the design of the load circuit, the utility model ensures that the lamp string can work stably after being connected to the circuit, avoids the situations of lamp string flashing and unstable brightness, and can adapt to different types of loads (resistors, capacitors, inductors, etc.), ensuring that the lamp string can operate stably under various load conditions, reducing the failure rate of the lamp string and improving the service life of the lamp string;

[0016] Through the design of the voltage stabilizing circuit, the voltage of the lamp string is kept stable within a certain range, not affected by the input voltage fluctuation and load change, and can automatically adjust the output voltage to prevent the lamp string from being damaged due to abnormal voltage. Brief Description of the Drawings

[0017] Figure 1 is the circuit diagram of the load circuit of the utility model;

[0018] Figure 2 is the circuit diagram of the voltage stabilizing circuit of the utility model. Detailed Embodiment

[0019] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the utility model.

[0020] Please refer to Figure 1-2 , the utility model provides a technical solution: a dimming control circuit for a lamp string, including a load circuit and a voltage stabilizing circuit. The load circuit includes a synchronous buck driving chip U8, and the model of the synchronous buck driving chip U8 is TPS92200D2DDCR. A capacitor C8 is connected between the 5th pin and the 6th pin of the synchronous buck driving chip U8, and the capacitance value of the capacitor C8 is 100uF. One end of the capacitor C8 is connected to an inductor L1. A series-connected light emitting diode group is connected between the 1st pin of the synchronous buck driving chip U8 and one end of the inductor L1. A DIM pin for receiving a PWM signal and realizing dimming is arranged on the synchronous buck driving chip U8. Capacitors C7, C12 and C2 which are connected in parallel and grounded are connected between the 3rd pin and the 4th pin of the synchronous buck driving chip U8.

[0021] The light emitting diode group is the LED lamp string. The DIM pin (pin 2) of the synchronous buck driving chip U8 receives the PWM signal for dimming.

[0022] The capacitance value of the capacitor C7 is 100uF, the capacitance value of the capacitor C12 is 10uF, and the capacitance value of the capacitor C2 is 10uF.

[0023] The light-emitting diode group includes light-emitting diodes LED12, LED13, LED14, LED15, LED16, and LED17 connected in series in sequence. The models of the above-mentioned multiple light-emitting diodes are all HL-EF13W3NAMS(Ra2).

[0024] A resistor R1 connected to ground is connected to the 1st pin of the synchronous buck driving chip U8, and a resistor R3 connected to ground is connected to the 2nd pin of the synchronous buck driving chip U8.

[0025] The output terminal of the light-emitting diode LED12 is connected to the resistor R1, and the input terminal of the light-emitting diode LED17 is connected to the inductor L1.

[0026] One end of the inductor L1 is connected to a capacitor C3 connected to ground. The capacitance value of the capacitor C3 is 10uF, and the 4th pin of the synchronous buck driving chip U8 outputs a 20V DC voltage.

[0027] The voltage stabilizing circuit includes a voltage stabilizing chip U6. The model of the voltage stabilizing chip U6 is ST1S14PHR. A capacitor C6 is connected between the 1st pin and the 8th pin of the voltage stabilizing chip U6. A diode D2 connected to ground is also connected to the 8th pin of the voltage stabilizing chip U6. A resistor R34 is connected to the 2nd pin of the voltage stabilizing chip U6. An inductor L3 is connected to the 8th pin of the voltage stabilizing chip U6. The connection terminals of the resistor R34 and the inductor L3 output a 5V voltage.

[0028] Both the 3rd pin and the 9th pin of the voltage stabilizing chip U6 are grounded.

[0029] A capacitor C69 and a resistor R104 connected in parallel are connected to the 4th pin of the voltage stabilizing chip U6. A resistor R103 connected to ground is connected to one connection terminal of the capacitor C69 and the resistor R104. The other connection terminal of the capacitor C69 and the resistor R104 is connected to the connection terminal between the resistor R34 and the inductor L3. The other connection terminal of the capacitor C69 and the resistor R104 is connected to a capacitor C1 connected to 5V. One end of the capacitor C1 is grounded.

[0030] A capacitor C74 and a capacitor C75 connected in parallel are connected between the 6th pin and the 7th pin of the voltage stabilizing chip U6. The 5th pin of the voltage stabilizing chip U6 is connected to the 7th pin, and a capacitor C73 is connected to the 5th pin of the voltage stabilizing chip U6, that is, the capacitor C73 is connected between the 5th pin and the 6th pin of the voltage stabilizing chip U6. One end of the capacitor C73 is connected to the connection terminal of the capacitor C74 and the capacitor C75.

[0031] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A light string dimming control circuit, characterized in that: It includes a load circuit and a voltage stabilizing circuit, wherein the load circuit includes a synchronous buck driver chip U8, a capacitor C8 is connected between pins 5 and 6 of the synchronous buck driver chip U8, one end of the capacitor C8 is connected to an inductor L1, a series-connected light-emitting diode group is connected between pin 1 of the synchronous buck driver chip U8 and one end of the inductor L1, a DIM pin for receiving a PWM signal and realizing dimming is provided on the synchronous buck driver chip U8, and capacitors C7, C12 and C2, which are arranged in parallel and grounded, are connected between pins 3 and 4 of the synchronous buck driver chip U8.

2. A light string dimming control circuit according to claim 1, characterized in that: A grounded resistor R1 is connected to pin 1 of the synchronous buck driving chip U8 , and a grounded resistor R3 is connected to pin 2 of the synchronous buck driving chip U8 .

3. A light string dimming control circuit according to claim 1, characterized in that: One end of the inductor L1 is connected to a grounded capacitor C3, and the pin 4 of the synchronous buck driver chip U8 outputs a 20V DC voltage.

4. A light string dimming control circuit according to claim 1, characterized in that: The voltage stabilizing circuit includes a voltage stabilizing chip U6, a capacitor C6 is connected between pins 1 and 8 of the voltage stabilizing chip U6, a grounded diode D2 is also connected to pin 8 of the voltage stabilizing chip U6, a resistor R34 is connected to pin 2 of the voltage stabilizing chip U6, and an inductor L3 is connected to pin 8 of the voltage stabilizing chip U6, and the connection terminals of the resistor R34 and the inductor L3 output a 5V voltage.

5. A light string dimming control circuit according to claim 4, characterized in that: The 4 pins of the voltage stabilizing chip U6 are connected to a capacitor C69 and a resistor R104 arranged in parallel, one terminal of the capacitor C69 and the resistor R104 is connected to a grounded resistor R103, the other terminal of the capacitor C69 and the resistor R104 is connected to the terminal of the resistor R34 and the inductor L3, and the other terminal of the capacitor C69 and the resistor R104 is connected to a capacitor C1 connected to 5V.

6. A light string dimming control circuit according to claim 5, characterized in that: The capacitors C74 and C75 are connected in parallel between the pins 6 and 7 of the voltage stabilizing chip U6. Pin 5 and pin 7 of the voltage regulator chip U6 are connected, and a capacitor C73 is connected to pin 5 of the voltage regulator chip U6. One end of the capacitor C73 is connected to the connection terminals of the capacitor C74 and the capacitor C75.

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