A dimming optimization circuit
By optimizing the components such as resistors, capacitors, Zener diodes, and MOSFETs in the dimming optimization circuit, the system automatically detects the connection of the phase-cut dimmer, thus solving the problem of inconsistent dimming performance of lamps in integrated dimming mode and achieving a stable dimming effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WUXI SEASTAR LIGHTING CO LTD
- Filing Date
- 2025-09-12
- Publication Date
- 2026-08-04
AI Technical Summary
Existing lighting fixtures, after integrating phase-cut dimming and 0-10V dimming functions, cannot simultaneously achieve optimal dimming performance, resulting in problems such as inability to dim at large phase-cut angles or output current overshoot.
A dimming optimization circuit is adopted, which automatically detects the connection of the phase cut dimmer through components such as resistor R3, resistor R4, capacitor C2, Zener diodes ZD1 and ZD2, MOSFET M1, and transistor Q2, and controls the COMP pin signal to maximize the PWM duty cycle output, thereby optimizing the dimming performance.
It enables automatic adjustment of circuit parameters under different dimmer conditions, ensuring consistency and stability of dimming performance, and avoiding insufficient dimming or current overshoot problems of phase-cut dimmers at large phase-cut angles.
Smart Images
Figure CN224596641U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of LED lighting technology, specifically to a dimming optimization circuit. Background Technology
[0002] As lighting fixture costs decrease, there is a growing market demand for integrating previously single-purpose or single-function lighting fixtures into a single unit to reduce SKUs and inventory. In the North American market, phase-cut dimming only requires an input voltage of 120V, while 0-10V dimming requires an input voltage range of 120V-277V. This means that the dimming performance of these integrated fixtures cannot be optimized for each component simultaneously. Phase-cut dimming performance often fails to match that of pure phase-cut dimming chips, frequently resulting in dimming failures at large phase-cut angles or output current overshoot. Utility Model Content
[0003] To solve the aforementioned technical problems, the inventor, based on his extensive experience in the field of LED lighting technology, developed a dimming optimization circuit.
[0004] To achieve the above technical objectives, this utility model adopts the following technical solution: a dimming optimization circuit, including a phase-cut dimmer, a resistor R4 connected to the phase-cut dimmer, a resistor R3 connected to the resistor R4, a capacitor C2 connected to one end of the resistor R3, a Zener diode ZD1 connected to the other end of the resistor R3, a MOSFET M1 connected to the MOSFET M1 connected to the base of a transistor Q2, a resistor R5 connected to the collector of the transistor Q2 connected to the VCC port, and the emitter of the transistor Q2 connected to the COMP pin.
[0005] Furthermore, a resistor R6 is connected to the other side of the VCC port, and the resistor R6 is connected to the Zener diode ZD2, with the other end of the Zener diode ZD2 grounded.
[0006] Furthermore, the Zener diode ZD1 is connected to the gate of the MOSFET M1, the drain of the MOSFET M1 is connected to the transistor Q2, and the source of the MOSFET M1 is grounded.
[0007] Furthermore, the phase-cut dimmer sends a phase-cut dimming input signal bus. The dimming input signal bus is divided by resistors R3, R4 and C2, and then filtered to control the MOS transistor M1 to flip. The flip signal controls the current of VCC through transistor Q2 to charge COMP through resistor R5. Resistor R6 provides bias voltage. The Zener diodes ZD1 and ZD2 provide voltage limiting protection.
[0008] Compared with the prior art, the present invention has the following beneficial effects: By setting resistors R3, R4, R5 and R6, capacitor C2, COMP, Zener diodes ZD1 and ZD2, MOSFET M1 and transistor Q2, the present invention can automatically detect whether a phase-cut dimmer is connected to the input, and then control the COMP pin signal that determines the PWM duty cycle output of the chip. When a phase-cut dimmer is connected, the voltage of the COMP pin is pulled up to the maximum value, thereby making the TON of the PWM drive output turn to the maximum value. Attached Figure Description
[0009] Figure 1 This is the circuit diagram of this utility model.
[0010] Figure 2 This is the simulation circuit diagram.
[0011] Figure 3 This is a schematic diagram of the COMP signal waveform corresponding to the simulation of phase-cutting dimming. Detailed Implementation
[0012] 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.
[0013] like Figures 1-3 As shown, a dimming optimization circuit includes a phase-cut dimmer connected to a resistor R4. Resistor R4 is connected to resistor R3. One end of resistor R3 is connected to capacitor C2, and the other end is connected to Zener diode ZD1. Zener diode ZD1 is connected to MOSFET M1. MOSFET M1 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to resistor R5, which is connected to the VCC port. The emitter of transistor Q2 is connected to the COMP pin.
[0014] In this embodiment, a resistor R6 is connected to the other side of the VCC port. The resistor R6 is connected to the Zener diode ZD2, and the other end of the Zener diode ZD2 is grounded.
[0015] In this embodiment, the Zener diode ZD1 is connected to the gate of the MOSFET M1, the drain of the MOSFET M1 is connected to the transistor Q2, and the source of the MOSFET M1 is grounded.
[0016] In this embodiment, the phase-cut dimmer sends a phase-cut dimming input signal bus. The dimming input signal bus is divided by resistors R3, R4 and C2, and then filtered to control the MOS transistor M1 to flip. The flip signal controls the current of VCC through transistor Q2 to charge COMP through resistor R5. Resistor R6 provides bias voltage. The Zener diodes ZD1 and ZD2 provide voltage limiting protection.
[0017] like Figure 2 As shown, the resistance values are set to 1K, 50K, 100K, 150K, 200K, 300K and 325K respectively. The simulated phase-cut dimmer is dimming. As the resistance value increases, the corresponding phase angle decreases. The dimming changes from bright to dark. The simulation waveform of the change in the COMP pin voltage is shown.
[0018] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A dimming optimization circuit, comprising a phase-cut dimmer, characterized in that: The phase cut dimmer is connected to resistor R4, which is connected to resistor R3. One end of resistor R3 is connected to capacitor C2, and the other end is connected to Zener diode ZD1. Zener diode ZD1 is connected to MOSFET M1. MOSFET M1 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to resistor R5, which is connected to the VCC port. The emitter of transistor Q2 is connected to the COMP pin.
2. The dimming optimization circuit according to claim 1, characterized in that: A resistor R6 is connected to the other side of the VCC port. The resistor R6 is connected to the Zener diode ZD2, and the other end of the Zener diode ZD2 is grounded.
3. The dimming optimization circuit according to claim 1, characterized in that: The Zener diode ZD1 is connected to the gate of the MOSFET M1, the drain of the MOSFET M1 is connected to the transistor Q2, and the source of the MOSFET M1 is grounded.
4. The dimming optimization circuit according to claim 1, characterized in that: The phase-cut dimmer sends a phase-cut dimming input signal bus. The dimming input signal bus is divided by resistors R3 and R4 and capacitor C2, and then filtered to control the MOS transistor M1 to flip. The flip signal controls the current of VCC through transistor Q2 to charge COMP through resistor R5. Resistor R6 provides bias voltage. The Zener diodes ZD1 and ZD2 provide voltage limiting protection.