Constant current frequency reduction flash circuit and light strip

Abstract

A constant current frequency reduction circuit and LED strip include a main control unit U1. The main control unit U1 receives an input voltage at its receiving end and has a control end connected to an output end that supplies power to the LED chips. A capacitor C2 is connected between the positive and negative terminals of the output end. This application adopts a step-down non-isolated constant current driving scheme, operating in critical conduction mode. This scheme has a wide AC input voltage range of 90-265VAC, which can meet the requirements of most AC voltage inputs. At the same time, the constant current output accuracy is high, which can provide a stable and accurate current to the LED module. It requires fewer external components, improves system stability, and greatly reduces manufacturing costs. This scheme also has over-temperature protection and short-circuit protection functions, which can further improve product reliability.

Description

Technical Field

[0001] This utility model relates to the field of LED strips, and in particular to a constant current frequency reduction circuit and LED strip. Background Technology

[0002] High-voltage LED strip lights on the market use an LED light source and a resistor in series for voltage division and current limiting, with an external rectifier bridge for power supply. The rectifier bridge converts alternating current (AC) into pulsating direct current (DC). This DC voltage fluctuates periodically, with peaks and troughs. When this fluctuating DC is applied to the LED strip, the voltage across the LED light source changes accordingly. Since LEDs have an onset voltage, when the voltage across the LED is higher than the onset voltage, the LED starts to emit light, gradually brightening as the voltage increases; conversely, when the voltage decreases, the LED gradually dims. When the voltage across the LED is lower than the onset voltage, the LED turns off. Due to this periodic voltage variation after rectification, high-voltage LED strip lights using this principle suffer from flickering. This periodic flickering can cause eye fatigue and dizziness. Furthermore, this type of LED strip light cannot achieve voltage and current stabilization. When the input voltage changes, the voltage across the LED also changes. If the voltage rises above the LED's withstand voltage, the LED will burn out. Therefore, the lifespan of these LED strip lights is generally short. Utility Model Content

[0003] To solve the above problems, this technical solution provides a constant current frequency reduction lightning circuit and light strip.

[0004] To achieve the above objectives, the technical solution is as follows:

[0005] A constant current frequency reduction circuit includes a main control unit U1, the receiving end of the main control unit U1 is input voltage, the control end of the main control unit U1 is connected to an output end that supplies power to the LED beads, and a capacitor C2 is connected between the positive and negative terminals of the output end.

[0006] In some embodiments, a resistor R2 is provided between the positive and negative terminals of the output terminal.

[0007] In some embodiments, the positive terminal of the output is grounded through capacitor C1.

[0008] In some embodiments, the negative terminal of the output is connected to the main control unit U1 via an inductor L1.

[0009] In some embodiments, the acquisition terminal of the main control unit U1 is grounded through resistor R1.

[0010] This application also provides a light strip, including a light strip body, wherein the light strip body is provided with a constant current frequency reduction lightning circuit as described above, and the light strip body is also provided with a plurality of lamp beads connected to the constant current frequency reduction lightning circuit.

[0011] The beneficial effects of this application are:

[0012] This application adopts a step-down non-isolated constant current drive scheme, operating in critical conduction mode. This scheme has a wide AC input voltage range of 90~265VAC, which can meet the requirements of most AC voltage inputs. At the same time, the constant current output has high accuracy, which can provide stable and accurate current to the LED module. It requires fewer external components, improves system stability, and greatly reduces manufacturing costs. This scheme also has over-temperature protection and short-circuit protection functions, which can further improve product reliability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0014] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model. Detailed Implementation

[0015] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] Please refer to Figure 1 As shown, a constant current frequency reduction circuit includes a main control unit U1. The receiving end of the main control unit U1 receives the input voltage, and the control end of the main control unit U1 is connected to an output end that supplies power to the LED beads. A capacitor C2 is connected between the positive and negative terminals of the output end.

[0017] Specifically, the main control unit U1 integrates a rectifier bridge, freewheeling diode, and MOSFET, requiring very few external components. Pin 4 of U1 detects changes in the external voltage signal through sampling resistor R1 to control the turn-on and turn-off times of the MOSFET. These changes in the MOSFET's turn-on and turn-off times rapidly adjust the LED module current, resulting in high-precision constant current output. Filter capacitor C2 eliminates output current ripple, thus virtually eliminating LED module flicker.

[0018] In some embodiments, a resistor R2 is provided between the positive and negative terminals of the output terminal.

[0019] In some embodiments, the positive terminal of the output is grounded through capacitor C1.

[0020] In some embodiments, the negative terminal of the output is connected to the main control unit U1 via an inductor L1.

[0021] In some embodiments, the acquisition terminal of the main control unit U1 is grounded through resistor R1.

[0022] In implementation, the constant current frequency reduction circuit includes a chip U1, resistors R1 and R2, capacitors C1 and C2, and inductor L1. Pin 1 of chip U1 is connected to the live wire (L) of the input terminal, pin 7 of chip U1 is connected to the neutral wire (N) of the input terminal, pin 2 of chip U1 is used to simulate high voltage ground, one end of resistor R1 is connected to pin 4 of chip U1, and the other end is connected to pin 2 of chip U1, one end of inductor L1 is connected to pin 5 of chip U1, and the other end is connected to the negative terminal of the LED module, the positive terminal of capacitor C1 is connected to pin 6 of chip U1, the negative terminal of capacitor C1 is connected to pin 2 of chip U1, the positive terminal of capacitor C2 is connected to pin 6 of chip U1, and the negative terminal of capacitor C2 is connected to the negative terminal of the LED module, one end of resistor R2 is connected to pin 6 of chip U1, the other end of resistor R2 is connected to the negative terminal of the LED module, and pin 6 of chip U1 is connected to the positive terminal of the LED module.

[0023] This application presents a step-down non-isolated constant current drive scheme. The inductor current operates in critical conduction mode and features a wide input voltage range of 90–265V, high precision, high efficiency, and low noise.

[0024] This application also provides a light strip, including a light strip body, wherein the light strip body is provided with a constant current frequency reduction lightning circuit as described above, and the light strip body is also provided with a plurality of lamp beads connected to the constant current frequency reduction lightning circuit.

[0025] The above description is only a preferred embodiment of this application and is not intended to limit the scope of implementation of this application. Any other embodiments whose principles and basic structures are the same as or similar to those of this application are within the protection scope of this application.

Claims

1. A constant current frequency reduction lightning circuit, characterized in that, It includes a main control unit U1, the receiving end of the main control unit U1 receives the input voltage, the control end of the main control unit U1 is connected to the output end that supplies power to the LED beads, and a capacitor C2 is connected between the positive and negative terminals of the output end.

2. The constant current frequency reduction lightning circuit according to claim 1, characterized in that: A resistor R2 is also provided between the positive and negative terminals of the output terminal.

3. A constant current frequency reduction lightning circuit according to claim 2, characterized in that: The positive terminal of the output is grounded through capacitor C1.

4. A constant current frequency reduction lightning circuit according to claim 3, characterized in that: The negative terminal of the output is connected to the main control unit U1 through inductor L1.

5. A constant current frequency reduction lightning circuit according to claim 4, characterized in that: The acquisition terminal of the main control unit U1 is grounded through resistor R1.

6. A light strip, characterized in that, The light strip includes a light strip body, which is provided with a constant current frequency reduction lightning circuit as described in any one of claims 1-5, and the light strip body is also provided with a plurality of LED beads connected to the constant current frequency reduction lightning circuit.

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