Two-in-one dimming LED drive circuit

Abstract

The utility model provides a two-in-one dimming LED drive circuit, comprising a master control circuit module used for realizing phase cut dimming; the color temperature adjusting circuit module is electrically connected to the main control circuit module; the MCU circuit module is used for realizing the output of a 0-10V dimming PWM (Pulse Width Modulation) signal; and the 0-10V dimming circuit module is electrically connected to the MCU circuit module and is used for realizing dimming signal conversion. The utility model provides a two-in-one dimming LED drive circuit, which can be compatible with phase cutting and 0-10V dimming, and can realize the functions of color temperature adjustment and power adjustment.

Description

Technical Field

[0001] The utility model relates to the technical field of LED drive power supply, in particular to a two-in-one dimming LED drive circuit. Background Art

[0002] The dimming of lamps in the North American market is mainly based on phase-cut dimming, while 0-10V dimming also occupies a certain market share. Different application scenarios have different dimming methods, and the demand for combining these two types of dimming is increasing. This requires the power supply to have both phase-cut dimming and 0-10V dimming functions. Utility Model Content

[0003] The purpose of the utility model is to overcome the above problems existing in the prior art and provide a two-in-one dimming LED driving circuit, which has the functions of phase-cut dimming and 0-10V dimming and can be applied to different scenarios.

[0004] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0005] The utility model provides a two-in-one dimming LED driving circuit, comprising:

[0006] Main control circuit module, used to realize phase-cut dimming;

[0007] a color temperature adjustment circuit module, electrically connected to the main control circuit module; and

[0008] MCU circuit module, used to realize 0-10V dimming PWM signal output;

[0009] The 0-10V dimming circuit module is electrically connected to the MCU circuit module and is used to realize dimming signal conversion.

[0010] In one embodiment of the present utility model, the main control circuit module includes:

[0011] Control IC circuit;

[0012] A power conversion circuit, electrically connected to the control IC circuit; and

[0013] The input circuit module is electrically connected to the power conversion circuit.

[0014] In one embodiment of the present utility model, the input circuit module comprises:

[0015] A rectifier and filter circuit, used for being electrically connected to a phase-cutting dimmer; and

[0016] The discharge circuit is electrically connected to the rectification and filtering circuit.

[0017] In one embodiment of the present invention, the input circuit module further includes an active vibration elimination circuit, one end of the active vibration elimination circuit is electrically connected to the discharge circuit, and the other end of the active vibration elimination circuit is electrically connected to the power conversion circuit.

[0018] In one embodiment of the utility model, the LED driving circuit also includes an active dummy load circuit, an LED load and an MCU power supply circuit. The active dummy load circuit is electrically connected to the power conversion circuit for deepening the 0-10V dimming depth. The LED load is electrically connected to the active dummy load circuit, and the MCU power supply circuit is electrically connected to the LED load.

[0019] In one embodiment of the present invention, the color temperature adjustment circuit module includes:

[0020] A color temperature adjustment circuit electrically connected to the LED load; and

[0021] The color temperature gear detection circuit is electrically connected to the MCU circuit module and the MCU power supply circuit.

[0022] In one embodiment of the present invention, the color temperature adjustment circuit module further includes an MCU power supply circuit, and the MCU power supply circuit is electrically connected to the LED load.

[0023] In one embodiment of the present utility model, the 0-10V dimming circuit module includes:

[0024] A dimming signal transmission circuit, electrically connected to the MCU circuit module;

[0025] A power gear detection circuit, electrically connected to the MCU circuit module; and

[0026] The dimming signal detection circuit is electrically connected to the MCU circuit module.

[0027] In one embodiment of the present invention, the 0-10V dimming circuit module further includes a 0-10V to PWM circuit, and the 0-10V to PWM circuit is electrically connected to the dimming signal detection circuit.

[0028] In one embodiment of the present invention, the LED driving circuit further includes an over-temperature protection circuit, and the over-temperature protection circuit is electrically connected to the MCU circuit module.

[0029] In summary, the utility model provides a two-in-one dimming LED drive circuit, which realizes phase-cut dimming through a main control circuit module, and a 0-10V dimming circuit module realizes 0-10V dimming. It is compatible with phase-cut and 0-10V dimming, and the color temperature adjustment circuit module can adjust the color temperature, thereby realizing the functions of adjustable color temperature and adjustable power. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0031] Figure 1 It is the overall structural diagram of the utility model;

[0032] Figure 2 It is a circuit diagram of the overall structure of the utility model;

[0033] Figure 3 It is a simulation waveform diagram of the circuit diagram of the utility model. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0035] See also Figure 1 and Figure 2The utility model provides a two-in-one dimming LED driving circuit, which has the functions of phase-cut dimming and 0-10V dimming at the same time, and can be applied to different scenarios. Specifically, the LED driving circuit includes a main control circuit module, which is used to realize phase-cut dimming and an MCU circuit module. The main control circuit module includes a control IC circuit and a power conversion circuit. The control IC circuit is a chip U1, and the No. 4 pin of the chip U1 is grounded. The power conversion circuit is electrically connected to the control IC circuit. The power conversion circuit includes a transformer T, one end of the transformer T is connected to a diode D4 and a MOS tube Q6, one pin of the MOS tube Q6 is connected to a resistor R20 and then grounded, and the other pin of the MOS tube Q6 is connected to the No. 5 pin of the chip U1, and the other end of the transformer T is connected to a diode D1 and a diode D2. The No. 5 pin of the chip U1 is connected to the gate of the power MOS tube Q6 to control the power conversion circuit to perform energy conversion. The Ton_max (maximum conduction time) of the pin is fixed. When the AC input is not connected to the phase-cut dimmer, the lower the input voltage, the greater the Ton (conduction time) to maintain the constant output current. When the AC input is connected to the phase-cut dimmer, as the phase cut becomes larger and larger, the effective value of the AC input voltage becomes smaller and smaller, and the Ton (on time) of the 5th pin of the chip U1 becomes larger and larger until it reaches Ton_max (maximum on time). The output current is no longer constant but decreases as the effective value of the input voltage decreases, thus achieving the function of phase-cut dimming. The MCU circuit module consists of MCU U3.

[0036] See also Figure 1 and Figure 2In one embodiment of the utility model, the main control circuit module also includes an input circuit module, and the input circuit module is electrically connected to the power conversion circuit. The input circuit module includes a phase-cut dimmer, a rectifier filter circuit and a discharge circuit. One end of the phase-cut dimmer is connected to the AC input end, and the other end of the phase-cut dimmer is connected to the rectifier filter circuit. The discharge circuit is electrically connected to the rectifier filter circuit. The discharge circuit includes a capacitor C1, one end of the capacitor C1 is directly connected to the rectifier filter circuit, and the other end of the capacitor C1 is connected to the rectifier filter circuit after being connected to a resistor R3 and connected to the rectifier filter circuit and grounded. In one embodiment of the utility model, the input circuit module also includes an active vibration elimination circuit, one end of the active vibration elimination circuit is electrically connected to the discharge circuit, and the other end of the active vibration elimination circuit is electrically connected to the power conversion circuit. Specifically, the active vibration elimination circuit includes a MOS tube Q1, one pin of the MOS tube Q1 is connected to the resistor R5 and then to the ground, one pin of the MOS tube Q1 is connected to the capacitor C2 and then connected to a pin of the transistor Q5, another pin of the MOS tube Q1 is connected to the capacitor C2 and then connected to another pin of the transistor Q5, another pin of the transistor Q5 is connected to the diode D3 and the resistor R2 and then connected to the transformer T1 and the capacitor C1, and another pin of the transistor Q5 is connected to the resistor R4 and then connected to the resistor R2. When the dimming becomes smaller and smaller, the input current also becomes smaller, and some phase-cut dimmers cannot maintain continuous conduction. Flickering occurs. A passive discharge circuit is added to the main circuit to provide a certain current, and the thyristor is maintained continuously during small dimming to prevent the lamp from flickering. The passive discharge circuit is composed of capacitor C1 and resistor R3, one end of the capacitor C1 is connected to the positive electrode after the rectifier and filter circuit, the other end of the capacitor C1 is connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the negative electrode (P-GND) after the rectifier and filter circuit. When the phase-cut dimmer is triggered, a large current spike will be caused. This current spike will cause oscillation, resulting in false triggering of the dimmer or even damage to the dimmer. The peak current can be suppressed by inserting a damping resistor in series into the loop, but the power consumption of the damping resistor is high and it is only suitable for low-power applications. Therefore, an active vibration elimination circuit is added. When the dimmer is just triggered, the MOS tube Q1 is cut off, and the current of the power conversion circuit flows to the negative pole (P-GND) of the input loop through the resistor R5. The resistor R5 plays the role of damping oscillation at this time. At the same time, the input circuit charges the capacitor C2 through the resistor R2 and the diode D3. When the voltage of the capacitor C2 reaches the conduction threshold of the MOS tube Q1, the MOS tube Q1 is turned on, and the current of the power conversion circuit flows to the negative pole (P-GND) of the input loop through the drain-source of the MOS tube Q1. The damping resistor R5 only flows through the loop current in the short time when the phase-cut dimmer is triggered, and does not need to flow through the loop current throughout the entire power frequency cycle, which reduces the loss of the power supply and improves the efficiency. Figure 3As shown in the figure, it is a simulation waveform, curve a is the voltage waveform after the AC input of the phase-cut dimmer passes through the rectifier and filter circuit, curve b is the current waveform flowing through the drain and source of the MOS tube Q1, and curve c is the current waveform flowing through the resistor R5. It can be seen that most of the current passes through the MOS tube Q1 during the entire power frequency cycle, and only the instantaneous current triggered by the phase-cut dimmer flows through the resistor R5.

[0037] See also Figure 1 and Figure 2 In one embodiment of the utility model, the LED driving circuit further includes an active dummy load circuit, an LED load, an MCU power supply circuit and an over-temperature protection circuit, and the active dummy load circuit is electrically connected to the power conversion circuit. The active dummy load circuit includes a resistor R1 and a MOS tube Q2, one end of the resistor R1 is connected to the diode D4, and the other end of the resistor R1 is connected to a pin of the MOS tube Q2. The over-temperature protection circuit is electrically connected to the MCU circuit module. The LED load is electrically connected to the active dummy load circuit. The LED load includes a warm-colored LED and a cold-colored LED, and the warm-colored LED and the cold-colored LED are connected to the resistor R1. The MCU power supply circuit is electrically connected to the LED load. In one embodiment of the utility model, the MCU power supply circuit includes a voltage regulator chip LDO, and pin 2 of the voltage regulator chip LDO is connected to the resistor R1. Pin 12 of MCU U3 is connected to a pin of MOS tube Q3, pin 13 of MCU U3 is connected to a pin of MOS tube Q4, pin 14 of MCU U3 is connected to a pin of MOS tube Q2, and pin 15 of MCU U3 is connected to pin 7 of switch SW1 and then to pin 1 of switch SW1. The over-temperature protection circuit is electrically connected to MCU U3. The over-temperature protection circuit includes a thermistor NTC, one end of the thermistor NTC is connected to resistor R15, and one end of the thermistor NTC is connected to pin 7 of MCU U3.

[0038] See also Figure 1 and Figure 2In one embodiment of the utility model, the LED driving circuit further includes a color temperature adjustment circuit module and a 0-10V dimming circuit module, and the color temperature adjustment circuit module is electrically connected to the main control circuit module. The color temperature adjustment circuit module includes a color temperature adjustment circuit, and the color temperature adjustment circuit is electrically connected to the LED load. The color temperature adjustment circuit includes a MOS tube Q3 and a MOS tube Q4, a pin of the MOS tube Q3 is connected to the warm color LED, and a pin of the MOS tube Q4 is connected to the cold color LED. Pin 15 of the MCU U3 detects the voltage to determine the color temperature gear, and pin 12 of the MCU U3 outputs a corresponding warm color PWM signal to control the conduction and cutoff of the MOS tube Q3, so that the warm color LED light string flows through the corresponding current, and pin 13 of the MCU U3 outputs a corresponding cold color PWM signal to control the conduction and cutoff of the MOS tube Q4, so that the cold color LED light string flows through the corresponding current. The function of five-speed color temperature adjustment is realized. The following table shows the duty ratio of the PWM signal output by pin 12 / pin 13 of the MCU U3 corresponding to each color temperature gear.

[0039] Color temperature level 2700K 3000K 3500K 40000K 5000K MCU U3 pin 12 duty cycle 99％ 80％ 60％ 35％ 1％ MCU U3 pin 13 duty cycle 1％ 20％ 40％ 65％ 99％

[0040] See also Figure 1 and Figure 2 In one embodiment of the present invention, the color temperature adjustment circuit module further includes a color temperature gear detection circuit, which is electrically connected to the MCU U3. The color temperature gear detection circuit includes a switch SW1, and a resistor R6 is connected to pin 1 of the switch SW1, and resistors R14, R13, R12, R11, and R10 are connected to pins 2 to 6 of the switch SW1, respectively. When the switch SW1 is turned to the 1st gear, the No. 1 and No. 7 pins of the switch SW1 are connected to the No. 2 pin, and the resistor R6 is divided by the resistor R14. When the switch is turned to the 2nd gear, the No. 1 and No. 7 pins of the switch are connected to the No. 3 pin, and the resistor R6 is divided by the resistor R13. When the switch is turned to the 3rd gear, the No. 1 and No. 7 pins of the switch are connected to the No. 4 pin, and the resistor R6 is divided by the resistor R12. When the switch is turned to the 4th gear, the No. 1 and No. 7 pins of the switch are connected to the No. 5 pin, and the resistor R6 is divided by the resistor R11. When the switch is turned to the 5th gear, the No. 1 and No. 7 pins of the switch are connected to the No. 6 pin, and the resistor R6 is divided by the resistor R10. Pin 15 of MCUU3 detects these voltages to determine the color temperature gear, and pins 12 and 13 output the corresponding two complementary PWM signals.

[0041] See also Figure 1 and Figure 2In one embodiment of the utility model, the 0-10V dimming circuit module is electrically connected to the main control circuit module to realize 0-10V dimming. Specifically, the 0-10V dimming circuit module includes a dimming signal transmission circuit, which is electrically connected to the MCU U3. The dimming signal transmission circuit includes an optocoupler U4, wherein pin 1 of the optocoupler U4 is connected to resistor R7 and then connected to pin 6 of the MCU U3, pin 3 of the optocoupler U4 is connected to resistor R8 and then grounded, and pin 3 of the optocoupler U4 is also connected to pin 8 of the chip U1. In one embodiment of the utility model, the 0-10V dimming circuit module also includes a power gear detection circuit, which is electrically connected to the MCU U3. The power gear detection circuit includes a switch SW2, wherein pin 1 of the switch SW2 is connected to resistor R9 and connected to pin 9 of the MCU U3, and pins 2, 4 and 6 of the switch SW2 are respectively connected to resistors R16-R18. When the switch SW2 is turned to the 1st gear, the switch pins 1 and 2 are connected, and the resistors R9 and R16 divide the voltage. When the switch SW2 is turned to the 2nd gear, the switch pins 1 and 4 are connected, and the resistors R9 and R17 divide the voltage. When the switch is turned to the 3rd gear, the switch pins 1 and 6 are connected, and the resistors R9 and R18 divide the voltage. The MCU U3 pin 9 detects these three voltages to determine the power gear. When the lamp is in the high power gear and the maximum dimming, the MCU U3 outputs a 100% duty cycle, and the duty cycle of 5% dimming is 5%; the medium power gear is 80% of the high power gear, and the MCU U3 output duty cycle is 80% when the medium power gear is dimmed to the maximum, and the MCU U3 output duty cycle is 4% when the 5% dimming is dimmed; the low power gear is 60% of the high power gear, and the MCU U3 output duty cycle is 60% when the low power gear is dimmed to the maximum, and the MCU U3 output duty cycle is 3% when the 5% dimming is dimmed. The following table shows the correspondence between power levels and dimming duty cycle ranges.

[0042]

[0043] Since the dimming depth of the DIM pin of the chip U1 can only reach 5%, the duty cycle below 5% cannot be recognized. When the power level is medium and low, the duty cycle of the dimming PWM signal is less than 5%, which is 4% and 3% respectively. Therefore, the minimum dimming of the power level is less than 5%. Therefore, the utility model adds an active dummy load circuit, which is composed of a resistor R1 and a MOS tube Q2. When the MCU U3 detects that the power level is in the medium and low power levels, and detects that the dimming signal is less than 5% duty cycle, the pin 14 of the MCU U3 outputs a high level and is connected to the gate of the MOS tube Q2. The MOS tube Q2 is turned on, the drain of the MOS tube Q2 is connected to one end of the resistor R1, and the other end of the resistor R1 is connected to the positive electrode of the constant current output. The source of the MOS tube Q1 is connected to the negative electrode of the constant current output. The conduction of the MOS tube Q2 is equivalent to connecting the resistor R1 between the positive and negative electrodes of the constant current output. The dummy load resistor R1 absorbs a part of the current of the constant current output by adjusting the appropriate resistance value. The constant current output can be reduced to achieve the purpose of deepening the dimming depth.

[0044] See also Figure 1 and Figure 2 In one embodiment of the utility model, the 0-10V dimming circuit module also includes a dimming signal detection circuit and a 0-10V to PWM circuit, the dimming signal detection circuit is electrically connected to the MCU U3, and the 0-10V to PWM circuit is electrically connected to the dimming signal detection circuit. The dimming signal detection circuit includes an optocoupler U6, pin 3 of the optocoupler U6 is connected to pin 11 of the MCU U3, and pin 3 of the optocoupler U6 is also connected to a resistor R19. The 0-10V to PWM circuit includes a chip U5, pin 4 of the chip U5 is connected to pin 1 of the optocoupler U6, pin 2 of the optocoupler U6 is grounded, pin 2 of the chip U5 is grounded, and pin 5 of the chip U5 is connected to a 0-10V dimmer, and the 0-10V dimmer is grounded. When the 0-10V dimmer input varies from 0V to 10V, the corresponding chip U5's pin 4 outputs a PWM signal with a duty cycle of 0% to 100%. This signal is connected to the 11th pin (dimming signal detection pin) of the MCU U3 through optocoupler isolation. The MCU U3 outputs a PWM signal with a duty cycle of 5% to 100% from the 6th pin according to the detected signal, and is isolated and fed back to the 8th pin (DIM interface) of the control IC through optocoupler U4 to adjust the output current of the main control circuit from 5% to 100%, thus realizing 0-10V dimming. When the power supply is working, the resistance value of the NTC is different at different temperatures, and the voltage divided by the 7th pin of the MCU U3 is different. The over-temperature protection point of the power supply is set by appropriately setting the value of the NTC and the resistor R15. When the temperature reaches the over-temperature protection point, the 6th pin of the MCU U3 outputs a 0% signal and shuts down the power supply output.

[0045] In summary, the utility model provides a two-in-one dimming LED drive circuit, which realizes phase-cut dimming through a main control circuit module, and a 0-10V dimming circuit module realizes 0-10V dimming. It is compatible with phase-cut and 0-10V dimming, and the color temperature adjustment circuit module can adjust the color temperature, thereby realizing the functions of adjustable color temperature and adjustable power.

[0046] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, and these changes and improvements fall within the scope of the utility model to be protected.

Claims

1. A two-in-one dimming LED driving circuit, characterized in that: include: Main control circuit module, used to realize phase-cut dimming; A color temperature adjustment circuit module, electrically connected to the main control circuit module; as well as MCU circuit module, used to realize 0-10V dimming PWM signal output; A 0-10V dimming circuit module, electrically connected to the MCU circuit module, for realizing dimming signal conversion; The main control circuit module comprises: Control IC circuit; A power conversion circuit, electrically connected to the control IC circuit; and An input circuit module, electrically connected to the power conversion circuit; The input circuit module comprises: A rectifier and filter circuit, used for being electrically connected to a phase-cutting dimmer; and A discharge circuit, electrically connected to the rectification and filtering circuit; The input circuit module further includes an active vibration elimination circuit, one end of which is electrically connected to the discharge circuit, and the other end of which is electrically connected to the power conversion circuit.

2. The two-in-one dimming LED driving circuit according to claim 1, characterized in that: The LED driving circuit also includes an active dummy load circuit, an LED load and an MCU power supply circuit. The active dummy load circuit is electrically connected to the power conversion circuit for deepening the 0-10V dimming depth. The LED load is electrically connected to the active dummy load circuit, and the MCU power supply circuit is electrically connected to the LED load.

3. The two-in-one dimming LED driving circuit according to claim 2, characterized in that: The color temperature adjustment circuit module comprises: A color temperature adjustment circuit electrically connected to the LED load; and The color temperature gear detection circuit is electrically connected to the MCU circuit module and the MCU power supply circuit.

4. The two-in-one dimming LED driving circuit according to claim 3, characterized in that: The color temperature adjustment circuit module further includes an MCU power supply circuit, and the MCU power supply circuit is electrically connected to the LED load.

5. The two-in-one dimming LED driving circuit according to claim 1, characterized in that: The 0-10V dimming circuit module includes: A dimming signal transmission circuit, electrically connected to the MCU circuit module; A power gear detection circuit, electrically connected to the MCU circuit module; and The dimming signal detection circuit is electrically connected to the MCU circuit module.

6. The two-in-one dimming LED driving circuit according to claim 5, characterized in that: The 0-10V dimming circuit module further includes a 0-10V to PWM circuit, and the 0-10V to PWM circuit is electrically connected to the dimming signal detection circuit.

7. The two-in-one dimming LED driving circuit according to claim 1, characterized in that: The LED driving circuit also includes an over-temperature protection circuit, and the over-temperature protection circuit is electrically connected to the MCU circuit module.

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