High-power LED lamp driving circuit and LED lamp string voltage drop detection method thereof

Abstract

The invention discloses a high-power LED lamp driving circuit and an LED lamp string voltage drop detection method thereof. The high-power LED lamp driving circuit comprises a controller, an LED lamp, a constant current source circuit, a first switch tube, a second switch tube and a third switch tube. The anode end and the cathode end of the LED lamp are respectively connected with an input voltage and a constant current source circuit, and the LED lamp is composed of a first LED lamp string, a second LED lamp string and a third LED lamp string which are sequentially connected between the anode end and the cathode end in series. A first control signal output interface, a second control signal output interface and a third control signal output interface of the controller are connected with controlled ends of a first switch tube, a second switch tube and a third switch tube respectively, the first switch tube, the second switch tube and the third switch tube are connected with a first LED lamp string, a second LED lamp string and a third LED lamp string respectively, and a first conduction end and a second conduction end of each switch tube are connected with an anode and a cathode of the corresponding LED lamp string respectively. The implementation cost is low, and it can be guaranteed that the constant current source circuit providing current for the LED lamp cannot be derated.

Description

Technical Field

[0001] The invention relates to an LED lamp driving circuit. Background Art

[0002] In the application of vehicle-mounted atmosphere lights, there are some special three-color atmosphere lights for warning purposes. This type of three-color atmosphere light has high requirements for brightness, so the current is very large. In order to meet the brightness requirements, this type of three-color atmosphere light driving circuit usually uses multiple constant current sources in parallel to expand the current flowing through the red LED lamp beads, green LED lamp beads and blue LED lamp beads, thereby achieving high brightness. The above solution has high requirements on the number of constant current source channels of the LED driver chip, which increases the manufacturing cost. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-power LED lamp driving circuit which has low implementation cost and can ensure that a constant current source circuit providing current to the LED lamp will not be derated.

[0004] Another technical problem to be solved by the present invention is to provide a method for detecting a voltage drop of an LED lamp string in a high-power LED lamp driving circuit.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] According to a first aspect of the present invention, a high-power LED lamp driving circuit is provided, comprising a controller, an LED lamp and a constant current source circuit, wherein the anode terminal and the cathode terminal of the LED lamp are respectively connected to an input voltage and the constant current source circuit, and the LED lamp is composed of first to third LED lamp strings connected in series between the anode terminal and the cathode terminal in sequence; its characteristic is that the high-power LED lamp driving circuit also includes first to third switching tubes; the first to third control signal output interfaces of the controller are respectively connected to the controlled ends of the first to third switching tubes, and the first to third switching tubes are respectively connected in parallel to the first to third LED lamp strings, wherein the first conduction end and the second conduction end of each switch tube are respectively connected to the anode and cathode of the corresponding LED lamp string.

[0007] According to a second aspect of the present invention, a method for detecting a voltage drop of an LED light string of a high-power LED lamp driving circuit is provided. The high-power LED lamp driving circuit includes a controller, an LED lamp, a constant current source circuit, and first to third PNP transistors; a power input interface of the controller is connected to an input voltage, an anode terminal and a cathode terminal of the LED lamp are respectively connected to the input voltage and the constant current source circuit, and the LED lamp is composed of first to third LED light strings connected in series between the anode terminal and the cathode terminal; first to third control signal output interfaces of the controller are respectively connected to the bases of the first to third PNP transistors, the first to third PNP transistors are respectively connected in parallel to the first to third LED light strings, and the emitter and collector of each PNP transistor are respectively connected to the anode and cathode of the corresponding LED light string; the method includes the following steps:

[0008] The controller synchronously outputs the first to third light-emitting control signals to the bases of the first to third PNP transistors respectively. Each control cycle of the three light-emitting control signals includes a T1 period, a T2 period and a T3 period which are connected in sequence. The durations of the T1 period, the T2 period and the T3 period are T1, T2 and T3 respectively. The sum of T1, T2 and T3 is equal to the duration T of the control cycle of the controller. Both T1 and T2 are greater than the voltage sampling period of the control signal output interface of the controller. The first to third light-emitting control signals are low level, high level and low level respectively in the T1 period, low level, low level and high level respectively in the T2 period, and are respectively from the T3 period. The starting moment continues at a low level, a low level and a high level, and the duration t1 of the first light-emitting control signal continuing at a low level in the T3 period is Duty_1-T1-T2, the duration t2 of the second light-emitting control signal continuing at a low level in the T3 period is Duty_2-T2, and the duration t3 of the third light-emitting control signal continuing at a high level in the T3 period is T3-Duty_3+T1, and Duty_1, Duty_2 and Duty_3 are respectively the given lighting times of the first to third LED light strings in the current control cycle; the first, second and third light-emitting control signals jump when the duration t1, duration t2 and duration t3 expire respectively;

[0009] The controller collects the voltage VS of the power input interface and the voltage values ​​Vled0, Vled1, and Vled2 of the first to third control signal output interfaces in real time, and calculates the voltage drop V1 of the first LED light string based on the Vled1 collected in the T1 period: V1=VS-V1ed1-Vbe2, and calculates the voltage drop V2 of the second LED light string based on the calculated V1 and the Vled2 collected in the T2 period: V2=VS-Vled2-V1-Vbe3; Vbe2 and Vbe3 are the base-emitter voltages of the second and third PNP transistors, respectively.

[0010] After adopting the above technical solution, the present invention has at least the following advantages and characteristics:

[0011] 1. The high-power LED lamp driving circuit of the embodiment of the present invention adopts a single external constant current source circuit to provide working current for the LED lamp, eliminating the requirement for the number of constant current source channels of the controller and reducing the implementation cost; the controller controls the three switch tubes respectively connected in parallel with the three LED light strings so that the three switch tubes are not disconnected at the same time, which can avoid the three LED light strings being lit at the same time at any time, thereby eliminating the phenomenon that the external constant current source circuit is derated due to the input voltage being too low (that is, the current output by the constant current source circuit is lower than the rated current);

[0012] 2. The LED lamp string voltage drop detection method of the high-power LED lamp driving circuit of the embodiment of the present invention can detect the voltage drop of the first LED lamp string and the second LED lamp string under the premise of avoiding the derating of the external constant current source circuit, so as to judge whether the working state of the LED lamp is normal according to the detected voltage drop of the first LED light string and the second LED light string, and use the voltage drop of the first LED light string for temperature compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A principle block diagram of a high-power LED lamp driving circuit according to an embodiment of the present invention is shown.

[0014] Figure 2 A circuit schematic diagram of a high-power LED lamp driving circuit according to an embodiment of the present invention is shown.

[0015] Figure 3 A schematic waveform diagram of one control cycle of three light-emitting control signals of a method for detecting a voltage drop of an LED light string according to an embodiment of the present invention is shown.

[0016] Figure 4 A schematic diagram of waveforms of three LED light strings in one control cycle of a method for detecting a voltage drop of an LED light string according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 and Figure 2 The circuit principle of a high-power LED lamp driving circuit according to an embodiment of the present invention is shown in FIG. Figure 1 and Figure 2 The high power LED lamp driving circuit 100 according to an embodiment of the present invention comprises a controller 1 , an LED lamp 2 , a constant current source circuit 3 , a first switch tube 41 , a second switch tube 42 , a third switch tube 43 , an input terminal circuit 5 and a LIN port protection circuit 6 .

[0019] The anode end and cathode end of the LED lamp 2 are connected to the input voltage VS1 and the constant current source circuit 3 respectively. The LED lamp 2 is composed of a first LED lamp string 21, a second LED lamp string 22 and a third LED lamp string 23 which are connected in series between the anode end and the cathode end. Each lamp string is composed of a single LED lamp bead or a plurality of LED lamp beads of the same color connected in series in the same direction. The meaning of "high power" described in this application means that the rated power of the LED lamp is greater than or equal to 1.5W (the power of each LED lamp string is 0.5W).

[0020] In some specific embodiments, the LED lamp 2 is a three-color ambient lamp, and the first LED light string 21, the second LED light string 22 and the third LED light string are a red LED light string, a green LED light string and a blue LED light string, respectively.

[0021] The constant current source circuit 3 is a transistor constant current source circuit, which includes an NPN transistor Q5, an NPN transistor Q4, a resistor R1 and a resistor R2; the collector of the NPN transistor Q5 is connected to the cathode of the LED lamp 2, the base of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R2 and the collector of the NPN transistor Q4, and the emitter of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R1 and the base of the NPN transistor Q4; the second end of the resistor R1 and the emitter of the NPN transistor Q4 are both grounded, and the second end of the resistor R2 is connected to the input voltage VS1. After the NPN transistor Q4 is turned on, the turn-on voltage of the resistor R1 is limited by the base-emitter voltage Vbe4 of the NPN transistor Q4, and the current flowing through the LED lamp 2 is approximately Vbe4 / R1 of the NPN transistor Q4.

[0022] The power input interface VS2 of the controller 1 is connected to the input voltage VS1, and the first control signal output interface LED0, the second control signal output interface LED1 and the third control signal output interface LED2 of the controller 1 are respectively connected to the controlled ends of the first switch tube 41, the second switch tube 42 and the third switch tube 43, and the first switch tube 41, the second switch tube 42 and the third switch tube 43 are respectively connected in parallel with the first LED light string 21, the second LED light string 22 and the third LED light string 23, wherein the first conduction end and the second conduction end of each switch tube are respectively connected to the anode and cathode of the corresponding LED light string.

[0023] In this embodiment, the first switch tube 41, the second switch tube 42 and the third switch tube 43 are respectively composed of a first PNP transistor Q1, a second PNP transistor Q2 and a third PNP transistor Q3. The base, emitter and collector of the PNP transistor respectively constitute the controlled end, the first conduction end and the second conduction end of the switch tube. Preferably, the operating parameters of the first PNP transistor Q1, the second PNP transistor Q2 and the third PNP transistor Q3 are the same. In other embodiments, the first switch tube 41, the second switch tube 42 and the third switch tube 43 are respectively composed of a PMOS tube.

[0024] In this embodiment, the controller 1 is a single chip microcomputer U1. The single chip microcomputer U1 uses a dedicated driver chip for automotive ambient lights, model TCPL010A, produced by Taishi Micro Corporation.

[0025] The input terminal circuit 5 includes a diode D101, a TVSD102, a capacitor C101 and a capacitor C102. The LIN port protection circuit 6 includes an ESD TVSD103, a magnetic bead B101, a capacitor C104 and a capacitor C105.

[0026] The input power supply KL30 provides power (input voltage VS1) to the microcontroller U1, the constant current source circuit 3 and the LED lamp 2 after passing through the anti-reverse diode D101. Among them, when the first control signal output interface LED0 of the controller 1 is turned on (that is, LED0 is in the on state) and pulls enough current, the PNP transistor Q1 is saturated and turned on. At this time, the current will flow through the PNP transistor Q1, and will not go through the first LED light string 21; when the first control signal output interface LED0 of the controller 1 is turned off, it is in an open drain state, and the PNP transistor Q1 is not turned on. At this time, the current flows through the first LED light string 21. The working principles of the second control signal output interface LED1 and the third control signal output interface LED2 are the same as those of LED0.

[0027] When the input voltage is too low (for example, lower than 9V), since the first to third LED light strings are connected in series to the collector of the NPN transistor Q5, if all three LED light strings are lit, the collector voltage of the NPN transistor Q5 will be too low, the NPN transistor Q5 will enter a saturated state, and the constant current source circuit 3 will be derated, resulting in failure to work normally, thereby affecting the brightness of the LED lamp 2. In this embodiment, a switch tube is connected in parallel next to each LED light string. By simply controlling the conduction of the switch tube, it can play a bypass role and prevent the LED light string connected in parallel with the switch tube from being lit. That is, the controller of the high-power LED lamp driving circuit of this embodiment controls the first to third switch tubes not to be disconnected at the same time (the three light control signals sent to LED0, LED1 and LED2 are not low at the same time), which can prevent the first to third LED light strings from being lit at the same time.

[0028] In some practical situations, in order to detect whether the working state of the LED lamp 1 is normal in real time, it is necessary to monitor the voltage drop of the LED lamp string while controlling the LED lamp string to turn on and off. A method for detecting the voltage drop of the LED lamp string by a high-power LED lamp driving circuit according to an embodiment of the present invention comprises the following steps:

[0029] The first control signal output interface LED0, the second control signal output interface LED1 and the third control signal output interface LED2 of the controller 1 synchronously output the first light-emitting control signal, the second light-emitting control signal and the third light-emitting control signal to the base of the first PNP transistor Q1, the second PNP transistor Q2 and the third PNP transistor Q3 respectively. Figure 3 As shown, each control cycle of the three light-emitting control signals includes a T1 period, a T2 period and a T3 period connected in sequence, the durations of the T1 period, the T2 period and the T3 period are T1, T2 and T3 respectively, the sum of T1, T2 and T3 is equal to the duration T of the control cycle of the controller, T1 and T2 are both greater than the voltage sampling period of the control signal output interface of the controller, the first light-emitting control signal, the second light-emitting control signal and the third light-emitting control signal are low level, high level and low level respectively in the T1 period, low level, low level and high level respectively in the T2 period, and continue the low level from the starting moment of the T3 period respectively. , low level and high level, and the duration t1 of the first light control signal continuing the low level in the T3 period is Duty_1-T1-T2, the duration t2 of the second light control signal continuing the low level in the T3 period is Duty_2-T2, the duration t3 of the third light control signal continuing the high level in the T3 period is T3-Duty_3+T1, Duty_1, Duty_2 and Duty_3 are respectively the given lighting time of the first to third LED light strings in the current control cycle; the first, second and third light control signals jump when the duration t1, duration t2 and duration t3 expire respectively;

[0030] The controller 1 collects the voltage VS of the power input interface VS2 in real time (since the power input interface VS2 is connected to the input voltage VS1, the voltage VS collected in real time is equal to VS1) and the voltage values ​​Vled0, Vled1, and Vled2 of the first control signal output interface LED0, the second control signal output interface LED1, and the third control signal output interface LED2. The voltage drop V1 of the first LED light string 21 is calculated based on the Vled1 collected during the T1 period: V1=VS-V1ed1-Vbe2, and the voltage drop V2 of the second LED light string 22 is calculated based on the calculated V1 and the Vled2 collected during the T2 period: V2=VS-Vled2-V1-Vbe3; Vbe2 and Vbe3 are the base-emitter voltages of the second PNP transistor and the third PNP transistor, respectively.

[0031] Figure 4 FIG. 1 is a schematic diagram showing current waveforms of three LED light strings in one control cycle according to a method for detecting voltage drop of an LED light string according to an embodiment of the present invention. Figure 4 It can be seen more intuitively that the current I0 of the first LED light string, the current I2 of the second LED light string, and the current I3 of the third LED light string will not be in a high state at the same time in the same control cycle. It can be seen that the three LED light strings will not be lit at the same time in one control cycle.

[0032] In this embodiment, the controller 1 uses a dedicated driver chip for automotive ambient lights, model TCPL010A, produced by Taishi Micro, and the duration T of its control cycle is 2ms. The voltage sampling period of the controller to collect the input voltage VS of the power input interface VS2 is 10μs. In some specific implementations, T1=T2=20μs, T3=1980μs.

[0033] In this embodiment, the first PNP transistor Q1, the second PNP transistor Q2 and the third PNP transistor Q3 have the same operating parameters, the base-emitter voltages of the first PNP transistor Q1 to the third PNP transistor Q3 are all equal to Vbe, and the collector-emitter voltages are all equal to Vce. The first LED light string 21, the second LED light string 22 and the third LED light string are respectively a red LED light string, a green LED light string and a blue LED light string.

[0034] The following is a more detailed introduction to the working principle of the LED light string voltage drop detection method of the high-power LED lamp driving circuit of the above-mentioned embodiment of the present invention for detecting the voltage drop of the first LED light string 21 (red LED light string in this embodiment) and the second LED light string 22 (green LED light string in this embodiment).

[0035] The first control signal output interface LED0, the second control signal output interface LED1 and the third control signal output interface LED2 all have two states: open and closed. The permutation and combination of the three control signals has a total of 8 states, as shown in the following table. 1 and 0 in the table represent high level (open state) and low level (closed state), respectively. When the first light-emitting control signal is at a low level, the first LED light string 21 will light up, when the second light-emitting control signal is at a low level, the second LED light string 22 will light up, and when the third light-emitting control signal is at a low level, the third LED light string will light up. Vr and Vg represent the voltage drops of the red LED light string and the green LED light string, respectively. The differential sampling voltage 1 refers to the difference between the voltage collected by the controller from the power input interface VS2 and the voltage collected from the second control signal output interface LED1. The differential sampling voltage 2 refers to the difference between the voltage collected by the controller from the power input interface VS2 and the voltage collected from the third control signal output interface LED2. The difference between the voltage collected by the controller from the power input interface VS2 and the voltage collected from the first control signal output interface LED0 is the differential sampling voltage 0. Take state ⑤ as an example: LED0 is turned off, the first PNP transistor Q1 is not conducting, and the current flows through the red LED light string; LED1 is turned on, the second PNP transistor Q2 is conducting, and the current does not flow through the green LED light string. At this time, the differential sampling voltage 1 is equal to the voltage drop Vr of the red LED light string plus the base-emitter voltage Vbe of the second PNP transistor Q2.

[0036] LED0 LED1 LED2 Differential sampling voltage 1 Differential sampling voltage 2 ① 1 1 1 Vbe+Vce 2*Vce+Vbe ② 1 1 0 Vbe+Vce / ③ 1 0 1 / Vce+Vg+Vbe ④ 1 0 0 / / ⑤ 0 1 1 Vr+Vbe Vr+Vce+Vbe ⑥ 0 1 0 Vr+Vbe / ⑦ 0 0 1 / Vr+Vg+Vbe ⑧ 0 0 0 / /

[0037] The above table shows more clearly which differential sampling voltage can detect the voltage drop of the red LED light string and the green LED light string, and then determine the state of the LED light string; when the detected red LED light string and the green LED light string do not meet the given normal operating voltage range, it is considered that the LED light is in an abnormal working state.

[0038] The voltage drop detection method of the LED light string of the high-power LED lamp driving circuit of the embodiment of the present invention uses the state ⑥ and state ⑦ in the table to detect the voltage drop of the first LED light string 21 and the second LED light string 22, and designs the timing control logic of each control cycle of the first to third light-emitting control signals. The first to third light-emitting control signals are all PWM control signals. By adjusting the duty cycle of each PWM control signal, different combinations and brightness of the three colors of red, green and blue are controlled to achieve different display effects. Among them, the T1 period adopts the above-mentioned state ⑥, and the voltage drop of the first LED light string 21 (red LED light string in this embodiment) can be monitored at this stage; the T2 period adopts the above-mentioned state ⑦, and this stage is used to monitor the voltage drop of the second LED light string 22 (green LED light string in this embodiment). The T1 and T2 periods are mainly used to collect the voltage drop of the first LED light string 21 and the second LED light string 22. In these two stages, LED0, LED1 and LED2 will not be in the state of 0 at the same time, that is, the first LED light string 21, the second LED light string 22 and the third LED light string 23 do not light up at the same time.

[0039] During the T3 period, the first light control signal output from the first control signal output interface LED0, the second light control signal output from the second control signal output interface LED1, and the third light control signal output from the third control signal output interface LED2 continue to be low level, low level, and high level after the T2 period ends, which also avoids the state where the three lights of the red LED light string, the green LED light string, and the blue LED light string are lit at the same time. The duration t1 of the first light control signal continuing the low level during the T3 period is Duty_1-T1-T2, the duration t2 of the second light control signal continuing the low level during the T3 period is Duty_2-T2, and the duration t3 of the third light control signal continuing the high level during the T3 period is T3-Duty_3+T1. Duty_1, Duty_2, and Duty_3 are the given lighting times of the first LED light string, the second LED light string, and the third LED light string in the current control cycle, respectively, which can be given by the brightness control algorithm of the LED light. The first light control signal jumps to a high level at the end of time t1, the second light control signal jumps to a high level at the end of time t2, and the third light control signal jumps to a low level at the end of time t3. At this time, only the blue LED string is on. Since the duration of a single control cycle is short, the naked eye cannot recognize the process of LED on and off.

Claims

1. A method for detecting a voltage drop of an LED lamp string of a high-power LED lamp driving circuit, wherein the high-power LED lamp driving circuit comprises a controller, an LED lamp and a constant current source circuit; the power input interface of the controller is connected to an input voltage, the anode terminal and the cathode terminal of the LED lamp are connected to the input voltage and the constant current source circuit respectively, and the LED lamp is composed of first to third LED lamp strings connected in series between the anode terminal and the cathode terminal in sequence; characterized in that: The high-power LED lamp driving circuit further includes first to third PNP transistors, the first to third control signal output interfaces of the controller are respectively connected to the bases of the first to third PNP transistors, the first to third PNP transistors are respectively connected in parallel to the first to third LED light strings, and the emitter and collector of each PNP transistor are respectively connected to the anode and cathode of the corresponding LED light string; The LED light string voltage drop detection method includes: The controller synchronously outputs the first to third light-emitting control signals to the bases of the first to third PNP transistors respectively. Each control cycle of the three light-emitting control signals includes a T1 period, a T2 period and a T3 period connected in sequence. The durations of the T1 period, the T2 period and the T3 period are T1, T2 and T3 respectively. The sum of T1, T2 and T3 is equal to the duration T of the control cycle of the controller. Both T1 and T2 are greater than the voltage sampling period of the control signal output interface of the controller. The first to third light-emitting control signals are low level, high level and low level respectively in the T1 period, low level, low level and high level respectively in the T2 period, and are respectively from the T3 period The first light control signal continues at a low level, a low level and a high level at the start time, and the duration t1 of the first light control signal continuing at a low level in the T3 period is Duty_1-T1-T2, the duration t2 of the second light control signal continuing at a low level in the T3 period is Duty_2-T2, and the duration t3 of the third light control signal continuing at a high level in the T3 period is T3-Duty_3+T1, and Duty_1, Duty_2 and Duty_3 are respectively the given lighting times of the first to third LED light strings in the current control cycle; the first, second and third light control signals jump when the duration t1, duration t2 and duration t3 expire respectively; The controller collects the voltage VS of the power input interface and the voltage values ​​Vled0, Vled1, and Vled2 of the first to third control signal output interfaces in real time, and calculates the voltage drop V1 of the first LED light string based on the Vled1 collected in the T1 period: V1=VS-V1ed1-Vbe2, and calculates the voltage drop V2 of the second LED light string based on the calculated V1 and the Vled2 collected in the T2 period: V2=VS-Vled2-V1-Vbe3; Vbe2 and Vbe3 are the base-emitter voltages of the second and third PNP transistors, respectively.

2. The method for detecting voltage drop of an LED lamp string of a high-power LED lamp driving circuit according to claim 1, characterized in that: The operating parameters of the first to third PNP transistors are the same.

3. The method for detecting voltage drop of an LED lamp string of a high-power LED lamp driving circuit according to claim 1, characterized in that: The LED light is a three-color ambient light, and the first to third LED light strings are a red LED light string, a green LED light string, and a blue LED light string, respectively.

4. The method for detecting voltage drop of an LED lamp string of a high-power LED lamp driving circuit according to claim 1, characterized in that: The controller is a single chip microcomputer.

5. The method for detecting voltage drop of an LED lamp string of a high-power LED lamp driving circuit according to claim 1, characterized in that: The constant current source circuit is a triode constant current source circuit, and the triode constant current source circuit includes an NPN triode Q5, an NPN triode Q4, a resistor R1 and a resistor R2; The collector of the NPN transistor Q5 is connected to the cathode of the LED lamp, the base of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R2 and the collector of the NPN transistor Q4, and the emitter of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R1 and the base of the NPN transistor Q4; The second end of the resistor R1 and the emitter of the NPN transistor Q4 are both grounded, and the second end of the resistor R2 is connected to the input voltage.

6. A high-power LED lamp driving circuit, comprising a controller, an LED lamp and a constant current source circuit, wherein the anode terminal and the cathode terminal of the LED lamp are respectively connected to an input voltage and the constant current source circuit, and the LED lamp is composed of first to third LED lamp strings connected in series between the anode terminal and the cathode terminal; characterized in that: The high-power LED lamp driving circuit also includes first to third switch tubes; The first to third control signal output interfaces of the controller are respectively connected to the controlled ends of the first to third switch tubes, and the first to third switch tubes are respectively connected in parallel to the first to third LED light strings, wherein the first conduction end and the second conduction end of each switch tube are respectively connected to the anode and cathode of the corresponding LED light string.

7. The high-power LED lamp driving circuit according to claim 6, characterized in that: The constant current source circuit is a triode constant current source circuit, and the triode constant current source circuit includes an NPN triode Q5, an NPN triode Q4, a resistor R1 and a resistor R2; The collector of the NPN transistor Q5 is connected to the cathode of the LED lamp, the base of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R2 and the collector of the NPN transistor Q4, and the emitter of the NPN transistor Q5 is connected to the common connection point of the first end of the resistor R1 and the base of the NPN transistor Q4; The second end of the resistor R1 and the emitter of the NPN transistor Q4 are both grounded, and the second end of the resistor R2 is connected to the input voltage.

8. The high-power LED lamp driving circuit according to claim 6, characterized in that: The first to third switch tubes are all PNP triodes, and the base, emitter and collector of the PNP triode respectively constitute the controlled end, the first conduction end and the second conduction end of the switch tube.

9. The high-power LED lamp driving circuit according to claim 5, characterized in that: The controller is a single chip microcomputer.

10. The high-power LED lamp driving circuit according to claim 5, characterized in that: The LED light is a three-color ambient light, and the first to third LED light strings are a red LED light string, a green LED light string, and a blue LED light string, respectively.

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