LED driver and power adaptive regulation method thereof

Abstract

The application discloses an LED driver and a power self-adaptive adjusting method thereof, and the power self-adaptive adjusting method comprises the following steps: a control circuit controls an adjustable constant current driving circuit to output a current to an LED lamp bead load in a set detection period, and the control circuit detects a difference between a starting voltage and a terminal voltage of the LED lamp bead load in the detection period; then, the control circuit controls a value of the maximum output current of the adjustable constant current driving circuit output to the LED lamp bead load according to the difference between the starting voltage and the terminal voltage of the LED lamp bead load, so that the maximum output power of the LED driver output to the LED lamp bead load is autonomously adjusted to adapt to LED lamp bead loads with different powers, and the user is more convenient and safe when using the LED lamp.

Description

Technical Field

[0001] The present invention relates to the field of LED lamps, and in particular to an LED driver and a method for adaptively adjusting power thereof. Background Art

[0002] In the prior art, existing LED drivers have multiple output power settings to set the maximum output power (i.e., maximum output current) that the LED driver can deliver to the LED lamp load, thereby matching LED lamp loads of varying power. Existing LED drivers primarily use DIP switches to manually switch between different output power settings. However, using DIP switches to select the driver's output power setting requires manual configuration by the user, requiring specialized knowledge. If the user selects the wrong setting, the driver can output excessive power, potentially damaging the LED lamp load. Therefore, it is necessary to develop an LED driver and its own adaptive power regulation method that can autonomously adjust the maximum output power delivered by the LED driver to the LED lamp load to accommodate LED lamp loads of varying power, thereby making LED lamp use more convenient and safer for users. Summary of the Invention

[0003] The object of the present invention is to provide an LED driver and a method for adaptively adjusting power thereof, so that the LED driver can autonomously adjust the maximum output power output by the LED driver to the LED lamp bead load to adapt to LED lamp bead loads of different power, making it more convenient and safer for users to use LED lamps.

[0004] In order to achieve the above object, the solution of the present invention is:

[0005] An LED driver includes an adjustable constant current drive circuit, a control circuit, and a voltage sampling circuit. The control circuit is connected to the adjustable constant current drive circuit and the voltage sampling circuit, respectively. The control circuit performs timed voltage sampling on the total voltage of an LED lamp bead load connected to the adjustable constant current drive circuit via the voltage sampling circuit, and the control circuit automatically controls the output current of the adjustable constant current drive circuit based on the sampling results.

[0006] The adjustable constant current driving circuit includes a constant current driving chip U1 , and the model of the constant current driving chip U1 is LC5228.

[0007] The control circuit includes an MCU processor U2, and the model of the MCU processor U2 is EFR32MG21.

[0008] The voltage sampling circuit includes a resistor R3 and a resistor R4, wherein the first end of the resistor R3 and the first end of the resistor R4 are respectively connected to the positive sampling end and the negative sampling end of the voltage sampling circuit, the second end of the resistor R3 and the second end of the resistor R4 are connected and connected together to the output end of the voltage sampling circuit, and the output end of the voltage sampling circuit is connected to an input end of the control circuit.

[0009] A method for adaptively regulating power of an LED driver as described above includes:

[0010] Step 1: Connect the positive output terminal and negative output terminal of the adjustable constant current drive circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected, and connect the positive sampling terminal and negative sampling terminal of the voltage sampling circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected;

[0011] Step 2: The control circuit controls the adjustable constant current drive circuit to output current to the LED lamp bead load within the set detection period, and the control circuit controls the output current value of the adjustable constant current drive circuit to the LED lamp bead load within the detection period to be the set detection current value; at the same time, the control circuit collects the starting voltage and ending voltage of the LED lamp bead load through the voltage sampling circuit; the starting voltage of the LED lamp bead load is the total voltage of the LED driver at the starting moment of the detection period, and the ending voltage of the LED lamp bead load is the total voltage of the LED driver at the ending moment of the detection period;

[0012] Step 3: The control circuit subtracts the starting voltage and the ending voltage of the LED lamp bead load to obtain the difference between the starting voltage and the ending voltage of the LED lamp bead load. At the same time, the control circuit determines to which of the multiple power levels the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs. Then, the control circuit controls the maximum output current value of the adjustable constant current drive circuit to the LED lamp bead load according to the power level to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power of the LED driver to the LED lamp bead load.

[0013] The duration of the detection period is 10 minutes to 60 minutes.

[0014] There are four set power gears; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is less than the first voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the first power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the first power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the first voltage comparison value and less than the second voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the second power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the second power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the second voltage comparison value and less than the third voltage comparison value When the voltage comparison value is greater than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the third power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the third power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the fourth power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the fourth power gear current value; the first voltage comparison value, the second voltage comparison value and the third voltage comparison value increase in sequence, the first power gear current value, the second power gear current value, the third power gear current value and the fourth power gear current value decrease in sequence, and the detection current value is less than or equal to the fourth power gear current value.

[0015] The first voltage comparison value is 50mV, the second voltage comparison value is 75mV, and the third voltage comparison value is 100mV; the first power gear current value is 300mA, the second power gear current value is 250mA, the third power gear current value is 200mA, and the fourth power gear current value is 150mA.

[0016] The detection current value is 100mA.

[0017] The positive sampling terminal and the negative sampling terminal of the voltage sampling circuit are respectively connected to the positive output terminal and the negative output terminal of the adjustable constant current driving circuit.

[0018] After adopting the above scheme, an LED driver and its power adaptive adjustment method of the present invention can automatically detect the difference between the starting voltage and the ending voltage of LED lamp bead loads of different powers, and automatically determine which of the set multiple power gears the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to, and automatically control the maximum output current value of the adjustable constant current drive circuit output to the LED lamp bead load according to the power gear to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power output by the LED driver to the LED lamp bead load, thereby realizing autonomous adjustment of the maximum output power output by the LED driver to the LED lamp bead load to adapt to LED lamp bead loads of different powers, making it more convenient and safer for users to use LED lamps. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the method steps of the present invention;

[0020] Figure 2 Schematic diagram of circuit connection of the present invention. DETAILED DESCRIPTION

[0021] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0022] like Figure 1 and 2 As shown, the present invention discloses an LED driver and a power adaptive regulation method thereof, wherein the LED driver includes an adjustable constant current drive circuit, a control circuit and a voltage sampling circuit, wherein the control circuit is connected to the adjustable constant current drive circuit and the voltage sampling circuit respectively; wherein the control circuit performs timed voltage sampling on the total voltage of the LED lamp bead load connected to the adjustable constant current drive circuit through the voltage sampling circuit, and the control circuit automatically controls the output current of the adjustable constant current drive circuit according to the sampling result.

[0023] Cooperate Figure 1 As shown, the power adaptive regulation method of the present invention includes:

[0024] Step 1: Connect the positive output terminal and negative output terminal of the adjustable constant current drive circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected, and connect the positive sampling terminal and negative sampling terminal of the voltage sampling circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected;

[0025] Step 2: The control circuit controls the adjustable constant current drive circuit to output current to the LED lamp bead load within the set detection period, and the control circuit controls the output current value of the adjustable constant current drive circuit to the LED lamp bead load within the detection period to be the set detection current value; at the same time, the control circuit collects the starting voltage and ending voltage of the LED lamp bead load through the voltage sampling circuit; wherein the starting voltage of the LED lamp bead load is the total voltage of the LED driver at the starting moment of the detection period, and the ending voltage of the LED lamp bead load is the total voltage of the LED driver at the ending moment of the detection period;

[0026] Step 3: The control circuit subtracts the starting voltage and the ending voltage of the LED lamp bead load to obtain the difference between the starting voltage and the ending voltage of the LED lamp bead load. At the same time, the control circuit determines to which of the multiple power levels the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs. Then, the control circuit controls the maximum output current value of the adjustable constant current drive circuit to the LED lamp bead load according to the power level to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power of the LED driver to the LED lamp bead load.

[0027] In the present invention, a power adaptive adjustment method of an LED driver of the present invention realizes automatic detection of the difference between the starting voltage and the ending voltage of LED lamp bead loads of different powers, and automatically determines to which of the set multiple power gears the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, and automatically controls the value of the maximum output current output by the adjustable constant current drive circuit to the LED lamp bead load according to the power gear to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power output by the LED driver to the LED lamp bead load, thereby realizing autonomous adjustment of the maximum output power output by the LED driver to the LED lamp bead load to adapt to LED lamp bead loads of different powers, making it more convenient and safer for users to use LED lamps.

[0028] The principle of the present invention is as follows: the LED lamp beads in the LED lamp bead load are a kind of diode, and the forward voltage of the diode will decrease as the temperature rises. Utilizing this characteristic, the present invention outputs a constant current to the LED lamp bead load through an adjustable constant current drive circuit within a set detection period, and then detects the difference between the starting voltage and the ending voltage of the LED lamp bead load (that is, detects the decrease in the forward voltage of the LED lamp bead load within the detection period). The temperature rise rate of the LED lamp is calculated based on the difference between the starting voltage and the ending voltage of the LED lamp bead load, and then the maximum power that the LED lamp bead load and its matching heat dissipation system can withstand is calculated; wherein, the present invention sets multiple power gears Each power level corresponds to the maximum power that a different LED lamp bead load and its matching heat dissipation system can withstand, and each power level is set with a corresponding voltage difference interval. The control circuit determines which voltage difference interval the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to, and thus determines which power level the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to. Then, the control circuit controls the maximum output current value of the adjustable constant current drive circuit to the LED lamp bead load according to the power level to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power of the LED driver to adapt to LED lamp bead loads of different power.

[0029] In the present invention, the number of power gears set by the present invention can be four; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is less than the first voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the first power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the first power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the first voltage comparison value and less than the second voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the second power gear, and the control circuit controls The maximum output current value of the adjustable constant current drive circuit output to the LED lamp bead load is the second power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the second voltage comparison value and less than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the third power gear, and the control circuit controls the maximum output current value of the adjustable constant current drive circuit output to the LED lamp bead load to be the third power gear current value; when the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the fourth The power gear is controlled by the control circuit, and the maximum output current value of the adjustable constant current drive circuit output to the LED lamp bead load is the fourth power gear current value; the first voltage comparison value, the second voltage comparison value and the third voltage comparison value increase in sequence, the first voltage comparison value can be 50mV, the second voltage comparison value can be 75mV, and the third voltage comparison value can be 100mV; the first power gear current value, the second power gear current value, the third power gear current value and the fourth power gear current value decrease in sequence, and the detection current value is less than or equal to the fourth power gear current value, the first power gear current value can be 300mA, the second power gear current value can be 250mA, and the third power gear current value can be 100mV. The current value can be 200mA, the fourth power level current value can be 150mA, and the detection current value can be 100mA; the first voltage comparison value, the second voltage comparison value, the third voltage comparison value, the first power level current value, the second power level current value, the third power level current value, the fourth power level current value and the detection current value can be set according to the power range of the LED lamp bead load that the LED driver can match. The detection current value can be half of the LED lamp bead load current corresponding to the minimum power of the LED lamp bead load that the LED driver can match. This can prevent the LED lamp bead load from burning, and at the same time can also ensure the temperature rise rate of the LED lamp bead load.The duration of the detection period can be 10 minutes to 60 minutes, so that the temperature difference between the LED lamp bead load at the start and end of the detection period is large enough, so that the difference between the starting voltage and the ending voltage of the LED lamp bead load can be detected; the length of the detection period is preferably 10 minutes to ensure user experience.

[0030] Cooperate Figure 2 As shown, the adjustable constant current drive circuit may include a constant current drive chip U1, an inductor L1, a Schottky diode D1, a resistor R1, and a resistor R2; the model of the constant current drive chip U1 may be LC5228, the IN pin of the constant current drive chip U1 and the first end of the inductor L1 are connected to the input end of the adjustable constant current drive circuit, the SW pin of the constant current drive chip U1 and the second end of the inductor L1 are connected to the positive electrode of the Schottky diode D1, the OV pin of the constant current drive chip U1 and the negative electrode of the Schottky diode D1 are connected to the positive output end of the adjustable constant current drive circuit, the FB pin of the constant current drive chip U1 and the first end of the resistor R2 are connected to the negative output end of the adjustable constant current drive circuit, the GND pin of the adjustable constant current drive circuit and the second end of the resistor R2 are grounded, the LD pin of the constant current drive chip U1 is connected to the first control end of the adjustable constant current drive circuit through the resistor R5, and the PWM pin of the constant current drive chip U1 is connected to the second control end of the adjustable constant current drive circuit through the resistor R1; the two output ends of the control circuit are connected to the adjustable The first control end and the second control end of the constant current drive circuit are connected respectively, and the control circuit inputs a power gear adjustment PWM signal and a brightness adjustment PWM signal into the first control end and the second control end of the adjustable constant current drive circuit respectively. The control circuit controls the output current of the adjustable constant current drive circuit by controlling the duty cycle of the power gear adjustment PWM signal and the duty cycle of the brightness adjustment PWM signal; wherein, the output current I of the adjustable constant current drive circuit = Imax*D1*D2, Imax is the maximum current value that the adjustable constant current drive circuit can theoretically output, D1 is the duty cycle of the power gear adjustment PWM signal, Imax*D1 is the maximum output current value of the adjustable constant current drive circuit controlled by the control circuit to output to the LED lamp bead load, the control circuit controls the maximum output current value of the adjustable constant current drive circuit output to the LED lamp bead load by controlling the size of D1, D2 is the duty cycle of the brightness adjustment PWM signal, and the size of D2 is used to control the luminous brightness of the LED lamp bead load.

[0031] Cooperate Figure 2 As shown, the control circuit includes an MCU processor U2, and the model of the MCU processor U2 may be EFR32MG21.

[0032] Cooperate Figure 2As shown, the voltage sampling circuit includes resistors R3 and R4. The first end of resistor R3 and the first end of resistor R4 are respectively connected to the positive sampling terminal and negative sampling terminal of the voltage sampling circuit. The positive sampling terminal and the negative sampling terminal of the voltage sampling circuit can be respectively connected to the positive output terminal and the negative output terminal of the adjustable constant current drive circuit to simplify wiring. The second end of resistor R3 and the second end of resistor R4 are connected and jointly connected to the output terminal of the voltage sampling circuit, and the output terminal of the voltage sampling circuit is connected to an input terminal of the control circuit. Resistors R3 and R4 of the voltage sampling circuit divide the total voltage of the LED driver and input it to the control circuit to prevent the voltage input to the control circuit from being too large. The MCU processor U2 of the control circuit can have a built-in AD converter to achieve analog-to-digital conversion.

[0033] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. An LED driver, characterized in that: The system comprises an adjustable constant current drive circuit, a control circuit and a voltage sampling circuit, wherein the control circuit is connected to the adjustable constant current drive circuit and the voltage sampling circuit respectively; the control circuit performs timed voltage sampling on the total voltage of the LED lamp bead load connected to the adjustable constant current drive circuit through the voltage sampling circuit, and the control circuit automatically controls the output current of the adjustable constant current drive circuit according to the sampling result; The power adaptive regulation method of the LED driver includes: Step 1: Connect the positive output terminal and negative output terminal of the adjustable constant current drive circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected, and connect the positive sampling terminal and negative sampling terminal of the voltage sampling circuit to the positive input terminal and negative input terminal of the LED lamp bead load to be connected; Step 2: The control circuit controls the adjustable constant current drive circuit to output current to the LED lamp bead load within the set detection period, and the control circuit controls the output current value of the adjustable constant current drive circuit to the LED lamp bead load within the detection period to be the set detection current value; at the same time, the control circuit collects the starting voltage and ending voltage of the LED lamp bead load through the voltage sampling circuit; the starting voltage of the LED lamp bead load is the total voltage of the LED driver at the starting moment of the detection period, and the ending voltage of the LED lamp bead load is the total voltage of the LED driver at the ending moment of the detection period; Step 3: The control circuit subtracts the starting voltage and the ending voltage of the LED lamp bead load to obtain the difference between the starting voltage and the ending voltage of the LED lamp bead load. At the same time, the control circuit determines to which of the multiple power levels the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs. Then, the control circuit controls the maximum output current value of the adjustable constant current drive circuit to the LED lamp bead load according to the power level to which the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs, thereby adjusting the maximum output power of the LED driver to the LED lamp bead load.

2. The LED driver according to claim 1, wherein: The adjustable constant current driving circuit includes a constant current driving chip U1 , and the model of the constant current driving chip U1 is LC5228.

3. The LED driver according to claim 1 or 2, wherein: The control circuit includes an MCU processor U2, and the model of the MCU processor U2 is EFR32MG21.

4. The LED driver according to claim 1, wherein: The voltage sampling circuit includes a resistor R3 and a resistor R4, wherein the first end of the resistor R3 and the first end of the resistor R4 are respectively connected to the positive sampling end and the negative sampling end of the voltage sampling circuit, the second end of the resistor R3 and the second end of the resistor R4 are connected and connected together to the output end of the voltage sampling circuit, and the output end of the voltage sampling circuit is connected to an input end of the control circuit.

5. The LED driver according to claim 1, wherein: The duration of the detection period is 10 minutes to 60 minutes.

6. The LED driver according to claim 1 or 5, wherein: There are four power levels that can be set; When the difference between the starting voltage and the ending voltage of the LED lamp bead load is less than the first voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the first power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the current value of the first power gear; When the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the first voltage comparison value and less than the second voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the second power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the second power gear current value; When the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than or equal to the second voltage comparison value and less than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the third power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the current value of the third power gear; When the difference between the starting voltage and the ending voltage of the LED lamp bead load is greater than the third voltage comparison value, the control circuit determines that the difference between the starting voltage and the ending voltage of the LED lamp bead load belongs to the fourth power gear, and the control circuit controls the maximum output current of the adjustable constant current drive circuit to the LED lamp bead load to be the current value of the fourth power gear; The first voltage comparison value, the second voltage comparison value and the third voltage comparison value increase successively, the first power gear current value, the second power gear current value, the third power gear current value and the fourth power gear current value decrease successively, and the detection current value is less than or equal to the fourth power gear current value.

7. The LED driver according to claim 6, wherein: The first voltage comparison value is 50 mV, the second voltage comparison value is 75 mV, and the third voltage comparison value is 100 mV; The current value of the first power gear is 300 mA, the current value of the second power gear is 250 mA, the current value of the third power gear is 200 mA, and the current value of the fourth power gear is 150 mA.

8. The LED driver according to claim 7, wherein: The detection current value is 100mA.

9. The LED driver according to claim 1, wherein: The positive sampling terminal and the negative sampling terminal of the voltage sampling circuit are respectively connected to the positive output terminal and the negative output terminal of the adjustable constant current driving circuit.

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