An LED lighting fixture circuit

Abstract

The utility model discloses a kind of LED lighting lamp circuit, including rectifier bridge, drive IC and switching power supply chip, the input end of rectifier bridge is connected 220V alternating current power supply, the output end of rectifier bridge is connected with the VDD pin of drive IC, the VCC pin of switching power supply chip inputs 5V voltage, the Drain pin of switching power supply chip and the VDD pin of drive IC are connected as signal output, the signal output is connected with one end of delay starter, one end of delay starter is connected with the anode of LED lamp string, the cathode of LED lamp string is connected with the other end of delay starter, the other end of delay starter is connected with the Drain pin of drive IC;The utility model is on the basis of conventional LED drive circuit, through π type filter, LC filter cooperate delay starter control drive IC work, make LED lamp pearl power current present exponential rise to rated current, reduce the impact to lamp pearl, prolong the service life of lamp pearl.

Description

Technical Field

[0001] This utility model relates to the field of LED driver circuit technology, and in particular to an LED lighting fixture circuit. Background Technology

[0002] Existing LED lighting fixtures are prone to large current surges to LED chips when switched on or off, which can easily damage the chips and cause the entire lamp to fail to light up. Therefore, a technical solution is needed to address the impact of large currents or high voltages on LED chips in the electronic circuitry of the lighting fixtures, thereby extending the lifespan of the chips. Summary of the Invention

[0003] To address the problems existing in the prior art, this utility model provides an LED lighting circuit that reduces the impact on the LED chips and extends their lifespan. To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: This utility model proposes an LED lighting circuit, including a rectifier bridge, a driver IC, and a switching power supply chip. The input terminal of the rectifier bridge is connected to a 220V AC power supply, and the output terminal of the rectifier bridge is connected to the VDD pin of the driver IC. The VCC pin of the switching power supply chip receives a 5V voltage, and the Drain pin of the switching power supply chip is connected to the VDD pin of the driver IC as a signal output. The signal output is connected to one end of a delay starter, one end of which is connected to the positive terminal of an LED string, the negative terminal of the LED string is connected to the other end of the delay starter, and the other end of the delay starter is connected to the Drain pin of the driver IC.

[0004] Furthermore, a varistor VR and a safety capacitor CX are connected in parallel to the input terminal of the rectifier bridge.

[0005] Furthermore, the output terminal of the rectifier bridge is connected to a π-type filter, and the π-type filter is connected in parallel with a voltage divider resistor.

[0006] Furthermore, the signal output is connected in parallel with an RC circuit.

[0007] Furthermore, an LC low-pass filter circuit is provided between the negative terminal of the LED string and the drain pin of the driver IC.

[0008] Compared with the prior art, the present invention has the following technical effects: Based on the traditional LED driver circuit, this utility model uses a π-type filter and an LC filter in conjunction with a time-delay starter to control the operation of the driver IC, so that the LED lamp bead supply current increases exponentially to the rated current, reducing the impact on the lamp bead and extending the lamp bead's service life. Attached Figure Description

[0009] Figure 1 This is a circuit diagram of this application; Figure 2 This is a schematic diagram of the delayed starter principle of this application.

[0010] The parts in the attached diagram are labeled as follows: U1 driver IC, U2 switching power supply chip, U3 time-delay starter, BR rectifier bridge L1 (first inductor), L2 (second inductor), VR (varistor), CX (safety capacitor) C1 is the first capacitor, C2 is the second capacitor, C3 is the third capacitor, and C4 is the fourth capacitor. Detailed Implementation

[0011] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0012] This utility model discloses an LED lighting fixture circuit, such as... Figure 1 As shown, it includes a rectifier bridge BR, a driver IC U1, and a switching power supply chip U2. The driver IC is a BP2861CJ step-down LED constant current driver chip, and the switching power supply chip is a BP8501CH step-down constant voltage driver chip.

[0013] The input terminal of the rectifier bridge BR is connected to a 220V AC power supply. A varistor VR and a safety capacitor CX are connected in parallel to the input terminal of the rectifier bridge BR. The varistor VR is a 7D471, and the safety capacitor CX is 150nF / 275V.

[0014] The output of the rectifier bridge BR is connected to a π-type filter, which includes a first inductor L1, a first capacitor C1, and a second capacitor C2. In the π-type filter, the first inductor L1 is connected in parallel with a voltage divider resistor R1, which is 5.1KΩ, to prevent the first inductor L1 from failing at a specific frequency due to LC resonance.

[0015] LED light strings generate a large number of harmonics when switched at high frequencies. These harmonics radiate interference signals outward through the power lines. The π-type filter effectively filters out high-frequency harmonics through a combination of inductors and capacitors, reducing interference to other electronic devices.

[0016] The output of the rectifier bridge BR is connected to the VDD pin of the driver IC U1. The VCC pin of the switching power supply chip U2 receives a 5V voltage. The Drain pin of the switching power supply chip U2 is connected to the VDD pin of the driver IC U1 as a signal output.

[0017] like Figure 1 As shown, the signal output is connected to one end of the delay starter U3, one end of the delay starter U3 is connected to the positive terminal of the LED string, the negative terminal of the LED string is connected to the other end of the delay starter U3, and the other end of the delay starter U3 is connected to the Drain pin of the driver IC U1.

[0018] like Figure 2 As shown, after using the time-delay starter U3, the initial current supply is relatively small, which has little impact on the LED beads in the LED string and the lights are relatively dim. After one second, the current increases to the normal value, and all the LED beads in the LED string light up. At this time, the beads are less affected by the impact, thus extending their service life.

[0019] The signal output is connected in parallel with an RC circuit, which includes a third capacitor C3 connected in parallel and a filter resistor R2. The RC circuit acts as a high-pass filter, and the filter resistor R2 is 330KΩ, which can reduce the influence of induced current.

[0020] An LC low-pass filter circuit is provided between the negative terminal of the LED string and the drain pin of the driver IC U1. The LC low-pass filter circuit includes a second inductor L2 and a fourth capacitor C4. The second inductor L2 is 3.9mH, which ensures that the driver IC U1 can achieve voltage reduction and stable output of the power supply.

[0021] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structure made using the contents of this utility model specification and drawings, or directly or indirectly applied to other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A circuit for an LED lighting fixture, characterized in that, The device includes a rectifier bridge (BR), a driver IC (U1), and a switching power supply chip (U2). The input terminal of the rectifier bridge (BR) is connected to a 220V AC power supply. The output terminal of the rectifier bridge (BR) is connected to the VDD pin of the driver IC (U1). The VCC pin of the switching power supply chip (U2) receives a 5V voltage. The Drain pin of the switching power supply chip (U2) is connected to the VDD pin of the driver IC (U1) as a signal output. The signal output is connected to one end of a delay starter (U3). One end of the delay starter (U3) is connected to the positive terminal of the LED string. The negative terminal of the LED string is connected to the other end of the delay starter (U3). The other end of the delay starter (U3) is connected to the Drain pin of the driver IC (U1).

2. The LED lighting circuit according to claim 1, characterized in that, A varistor (VR) and a safety capacitor (CX) are connected in parallel to the input of the rectifier bridge (BR).

3. The LED lighting circuit according to claim 1, characterized in that, The output terminal of the rectifier bridge (BR) is connected to a π-type filter, and the π-type filter is connected in parallel with a voltage divider resistor.

4. The LED lighting circuit according to claim 1, characterized in that, The signal output is connected in parallel with an RC circuit.

5. The LED lighting circuit according to claim 1, characterized in that, An LC low-pass filter circuit is provided between the negative terminal of the LED string and the Drain pin of the driver IC (U1).

Images