AC input non-flickering LED soft strip without electrolytic capacitor

Abstract

The utility model provides a kind of no strobe LED soft lamp strip of alternating current input electrolytic capacitor, including rectifier DB1, filter formed by at least two patch ceramic capacitors in series, high voltage control chip U1, LED lamp string, freewheeling diode D1 and freewheeling diode D2, wherein, the pin 1 of rectifier DB1 is connected with alternating current live wire, the pin 2 of rectifier DB1 is connected with alternating current zero line, one end of the filter is connected with the pin 4 of rectifier DB1.The utility model has the beneficial effects that the utility model provides a kind of no strobe LED soft lamp strip of alternating current input electrolytic capacitor, can solve the problem of strobe without using electrolytic capacitor, and can keep size unchanged and improve the service life of product.

Description

Technical Field

[0001] This utility model relates to lighting devices, and more particularly to a flicker-free LED flexible light strip with AC input and electrolytic capacitor removal. Background Technology

[0002] Currently, existing AC input high-voltage LED strips generally suffer from flickering issues, making them unsuitable for home and office lighting due to the serious eye-hazardousness caused by flicker. Solving this problem requires adding electrolytic capacitors, but these large capacitors significantly impact the size of AC input high-voltage LED strips that require IP65 protection, thus hindering widespread adoption. Summary of the Invention

[0003] To address the problems in the prior art, this utility model provides a flicker-free LED flexible light strip with AC input and no electrolytic capacitor.

[0004] This utility model provides a flicker-free LED flexible light strip with AC input without electrolytic capacitors, including a rectifier bridge DB1, a filter consisting of at least two surface-mount ceramic capacitors connected in series, a high-voltage control chip U1, an LED string, a freewheeling diode D1, and a freewheeling diode D2. Pin 1 of the rectifier bridge DB1 is connected to the AC live wire, and pin 2 of the rectifier bridge DB1 is connected to the AC neutral wire. One end of the filter is connected to pin 4 of the rectifier bridge DB1, and the other end of the filter is connected to pin 8 of the high-voltage control chip U1. The anode of the LED string is connected to pin 9 of the high-voltage control chip U1, and the cathode of the LED string is connected to pin 4 of the rectifier bridge DB1. The anode of the freewheeling diode D1 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D1 is connected to pin 5 of the high-voltage control chip U1. The anode of the freewheeling diode D2 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D2 is connected to pin 8 of the high-voltage control chip U1.

[0005] As a further improvement of this utility model, the filter includes surface-mount ceramic capacitors C1, C2, C3, C4, C5, C6 and C7 connected in series.

[0006] As a further improvement of this utility model, the surface mount ceramic capacitors C1, C2, C3, C4, C5, C6 and C7 are all multilayer surface mount ceramic capacitors made of X7R material.

[0007] As a further improvement of this utility model, the flicker-free LED flexible light strip also includes a surface mount resistor R2 and a surface mount resistor R3. One end of the surface mount resistor R2 is connected to pin 1 of the high voltage control chip U1, and the other end of the surface mount resistor R2 is connected to pin 2 of the high voltage control chip U1. One end of the surface mount resistor R3 is connected to pin 1 of the high voltage control chip U1, and the other end of the surface mount resistor R3 is connected to pin 4 of the high voltage control chip U1. Pins 1 and 3 of the high voltage control chip U1 are connected.

[0008] As a further improvement of this utility model, the flicker-free LED flexible light strip also includes a fuse F1 and a varistor R1. One end of the fuse F1 is connected to the AC live wire, and the other end of the fuse F1 is connected to pin 1 of the rectifier bridge DB1. One end of the varistor R1 is connected to pin 1 of the rectifier bridge DB1, and the other end of the varistor R1 is connected to pin 2 of the rectifier bridge DB1.

[0009] As a further improvement of this utility model, the high-voltage control chip U1 is model number SM2502E.

[0010] The beneficial effects of this utility model are: This utility model provides a flicker-free LED flexible light strip with AC input without electrolytic capacitors, which can solve the flicker problem without using electrolytic capacitors, while maintaining the same size and improving the product's service life. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other solutions can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a circuit diagram of a flicker-free LED flexible light strip with AC input and electrolytic capacitor removal, according to this utility model. Detailed Implementation

[0013] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0014] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0015] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 1 As shown, a flicker-free LED flexible light strip with AC input electrolytic capacitor removal includes a rectifier bridge DB1, a filter consisting of at least two surface-mount ceramic capacitors connected in series, a high-voltage control chip U1, an LED string, a freewheeling diode D1, and a freewheeling diode D2. Pin 1 of the rectifier bridge DB1 is connected to the AC live wire, and pin 2 of the rectifier bridge DB1 is connected to the AC neutral wire. One end of the filter is connected to pin 4 of the rectifier bridge DB1, and the other end of the filter is connected to pin 8 of the high-voltage control chip U1. The anode of the LED string is connected to pin 9 of the high-voltage control chip U1, and the cathode of the LED string is connected to pin 4 of the rectifier bridge DB1. The anode of the freewheeling diode D1 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D1 is connected to pin 5 of the high-voltage control chip U1. The anode of the freewheeling diode D2 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D2 is connected to pin 8 of the high-voltage control chip U1.

[0018] Regardless of whether the input AC current is in the positive or negative half-cycle, the DB1 rectifier bridge, through the ingenious cooperation of its four internal diodes, guides the current to always flow into the same end of the load and out the other end, thus outputting DC current in a constant direction. Its core mission is to smoothly convert alternating current (AC) into direct current (DC).

[0019] The freewheeling diodes D1 and D2 can provide a continuous unidirectional flow path. The ES1J's 35ns ultrafast recovery time can significantly reduce switching losses, improve circuit efficiency, and reduce noise interference under high-frequency switching.

[0020] The filter includes surface-mount ceramic capacitors C1, C2, C3, C4, C5, C6, and C7 connected in series.

[0021] Surface mount ceramic capacitors, also known as multilayer ceramic chip capacitors (MLCCs), are indispensable basic components in modern electronic products. The surface mount ceramic capacitors C1, C2, C3, C4, C5, C6, and C7 mentioned above are all X7R multilayer ceramic chip capacitors. These capacitors have medium capacitance and good temperature stability. Here, multiple 50V surface mount ceramic capacitors are connected in series to form a filter similar to the function of an electrolytic capacitor, which can eliminate LED flicker, thus achieving a flicker-free function.

[0022] After being filtered by surface-mount ceramic capacitors, the current flowing through the LED string becomes smoother, reducing the impact on the LEDs and extending their lifespan.

[0023] The flicker-free LED flexible light strip also includes surface mount resistors R2 and R3. One end of surface mount resistor R2 is connected to pin 1 of the high voltage control chip U1, and the other end of surface mount resistor R2 is connected to pin 2 of the high voltage control chip U1. One end of surface mount resistor R3 is connected to pin 1 of the high voltage control chip U1, and the other end of surface mount resistor R3 is connected to pin 4 of the high voltage control chip U1. Pins 1 and 3 of the high voltage control chip U1 are connected.

[0024] The flicker-free LED flexible light strip also includes a fuse F1 and a varistor R1. One end of the fuse F1 is connected to the AC live wire, and the other end of the fuse F1 is connected to pin 1 of the rectifier bridge DB1. One end of the varistor R1 is connected to pin 1 of the rectifier bridge DB1, and the other end of the varistor R1 is connected to pin 2 of the rectifier bridge DB1.

[0025] The surface mount resistor R2 is the sampling resistor. The output operating current value is adjusted by changing R2. The surface mount resistor R3 is the strobe setting resistor. It is recommended to use a value that is 1.1 times the resistance value of R1.

[0026] Fuse F1 is a critical safety device in a circuit. Its core function is to cut off the circuit by melting itself when the current rises abnormally to a dangerous level, thereby protecting electronic equipment, wires and even the entire system from damage and preventing serious accidents such as fires.

[0027] The core function of the varistor R1 is to protect the circuit from abnormally high voltage surges, such as those caused by lightning strikes or transient surges during circuit switching. Under normal voltage conditions, it operates as an "open circuit": when the voltage across the circuit is within the normal range, the varistor's impedance is extremely high, and the current flowing through it is minimal, acting like a closed valve and not affecting the normal operation of the circuit. Under abnormally high voltage conditions, it momentarily "short-circuits": when a transient overvoltage occurs and exceeds the varistor's threshold voltage (called the "varistor voltage"), its impedance drops sharply, rapidly changing from megaohms to ohms. This is equivalent to a valve opening instantaneously, forming a low-resistance path that diverts the excess current, thus clamping the voltage across the circuit within a relatively safe, fixed range, protecting more delicate electronic components downstream from damage. This process is extremely fast, typically on the order of nanoseconds. A varistor may be damaged after being subjected to extreme surges exceeding its tolerance, usually manifesting as a short circuit. Therefore, in power supply circuits, it is often used in series with a fuse. When the varistor is short-circuited, the fuse will melt to completely cut off the circuit and prevent fire risk.

[0028] The preferred high-voltage control chip U1 is the SM2502E, a linear constant current control chip that supports flicker-free mobile phone photography. It allows for precise setting of the LED current via an external resistor. The chip features over-temperature regulation, enhancing system reliability. It meets >1KV lightning surge requirements, has a simple system structure, requires few external components, and offers low cost. For optimal system operation, the LED string voltage should be controlled between 240V and 260V.

[0029] LED light strings are composed of multiple LEDs connected in series, such as LED1 / 2 / 3...13 / 14. White LEDs are preferred, using six 3V chips connected in series to form an 18V single chip. The technical principle of white light generation mainly involves using a blue LED chip to excite phosphors. By adjusting the phosphor ratio, different color temperatures can be obtained, ranging from warm white (2700K-3500K) to neutral white (4000K-6000K) and even cool white (above 6000K), to meet the needs of various scenarios.

[0030] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A flicker-free LED flexible light strip with AC input without electrolytic capacitor, characterized in that: The device includes a rectifier bridge DB1, a filter consisting of at least two surface-mount ceramic capacitors connected in series, a high-voltage control chip U1, an LED string, a freewheeling diode D1, and a freewheeling diode D2. Pin 1 of the rectifier bridge DB1 is connected to the AC live wire, pin 2 of the rectifier bridge DB1 is connected to the AC neutral wire, one end of the filter is connected to pin 4 of the rectifier bridge DB1, and the other end of the filter is connected to pin 8 of the high-voltage control chip U1. The anode of the LED string is connected to pin 9 of the high-voltage control chip U1, and the cathode of the LED string is connected to pin 4 of the rectifier bridge DB1. The anode of the freewheeling diode D1 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D1 is connected to pin 5 of the high-voltage control chip U1. The anode of the freewheeling diode D2 is connected to pin 3 of the rectifier bridge DB1, and the cathode of the freewheeling diode D2 is connected to pin 8 of the high-voltage control chip U1.

2. The flicker-free LED flexible light strip with AC input electrolytic capacitor removal according to claim 1, characterized in that: The filter includes surface-mount ceramic capacitors C1, C2, C3, C4, C5, C6, and C7 connected in series.

3. The flicker-free LED flexible light strip with AC input and electrolytic capacitor removal according to claim 2, characterized in that: The surface mount ceramic capacitors C1, C2, C3, C4, C5, C6, and C7 are all multilayer surface mount ceramic capacitors made of X7R material.

4. The flicker-free LED flexible light strip with AC input electrolytic capacitor removal according to claim 1, characterized in that: The flicker-free LED flexible light strip also includes surface mount resistors R2 and R3. One end of surface mount resistor R2 is connected to pin 1 of the high voltage control chip U1, and the other end of surface mount resistor R2 is connected to pin 2 of the high voltage control chip U1. One end of surface mount resistor R3 is connected to pin 1 of the high voltage control chip U1, and the other end of surface mount resistor R3 is connected to pin 4 of the high voltage control chip U1. Pins 1 and 3 of the high voltage control chip U1 are connected.

5. The flicker-free LED flexible light strip with AC input electrolytic capacitor removal according to claim 1, characterized in that: The flicker-free LED flexible light strip also includes a fuse F1 and a varistor R1. One end of the fuse F1 is connected to the AC live wire, and the other end of the fuse F1 is connected to pin 1 of the rectifier bridge DB1. One end of the varistor R1 is connected to pin 1 of the rectifier bridge DB1, and the other end of the varistor R1 is connected to pin 2 of the rectifier bridge DB1.

Images