CN117939741A - Current self-adaptive adjusting circuit and adjusting method of LED power supply - Google Patents

The invention discloses a current self-adaptive regulating circuit and a regulating method of an LED power supply, wherein the current self-adaptive regulating circuit comprises a power supply main circuit, a feedback regulating loop, a singlechip circuit, a current detection circuit, a constant current regulating circuit and a current gear setting circuit; the feedback regulation loop is respectively connected with the power supply main circuit and the singlechip circuit; the constant current regulating circuit is respectively connected with the output end of the power supply main circuit, the singlechip circuit and the feedback regulating loop; the current detection circuit is connected between the constant current regulating circuit and the singlechip circuit; the current gear setting circuit is connected with the singlechip circuit; the singlechip circuit can output a first dimming signal and a second dimming signal and output the first dimming signal and the second dimming signal to a load through the constant current regulating circuit; the output current is detected in real time and compared with the set current gear, so that the current curve of any chip can be set with the current gear while the output current precision is ensured.

Current self-adaptive adjusting circuit and adjusting method of LED power supply

Technical Field

The invention relates to the field of LED power supplies, in particular to a current self-adaptive regulating circuit and a regulating method of an LED power supply.

Background

With the rapid development of the LED illumination industry, the LEDs are installed in various households and outdoor illumination, so that the LED power supply market is vigorously developed, and the requirements on the LED power supply are higher and higher.

The current gear of most constant current power supplies is selected by dialing, along with the continuous development of technology, a plurality of manufacturers adopt stepless current gear selection at present, as long as any current in the maximum current of the power supply can be set, the minimum current precision is even accurate to 1mA, but the method is to use the maximum power supply as a reference and to distribute the current according to the proportion, and the premise is that the current curve of the chip is a proportion curve, otherwise, each current gear needs to be tested once, or the current curve of the chip is obtained, and then the current gear is set according to the curve, so that the precision of the current gear is insufficient due to the fact that each chip is in error.

Therefore, it is necessary to develop a current adaptive adjustment circuit and an adjustment method for an LED power supply.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a current self-adaptive adjusting circuit and an adjusting method of an LED power supply.

The technical scheme adopted by the embodiment of the invention for solving the technical problems is as follows: a current self-adaptive adjustment method of an LED power supply comprises the following steps:

S1, setting a current gear X and an error Q;

s2, outputting a first dimming signal to the load, wherein the first dimming signal corresponds to the lowest brightness or the off brightness of the load;

S3, detecting the output current Z of the power supply, and comparing the current gear X with the output current Z;

And S4, outputting a second dimming signal to the load so that the current gear X outputs current Z=error Q.

As one of the preferred embodiments of the present invention, a current adaptive adjustment method of an LED power supply further includes:

S0, judging the sizes of the current gear X and the last current gear X, if the current gear X is greater than the last current gear X, the first dimming signal is the dimming signal corresponding to the last current gear X, and if the current gear X is smaller than the last current gear X, the first dimming signal corresponds to the lowest brightness or the off brightness of the load.

As one of the preferred embodiments of the present invention, if the first dimming signal corresponds to the minimum current when the load is at the lowest brightness or the off brightness, the second dimming signal is obtained by decrementing the first dimming signal;

If the first dimming signal corresponds to the maximum current when the load is at the lowest brightness or the off brightness, the second dimming signal is obtained by increasing the first dimming signal.

As one of the preferred embodiments of the present invention, the first dimming signal and the second dimming signal are set as PWM output signals or direct current output signals.

The current self-adaptive regulating circuit of the LED power supply comprises a power supply main circuit, a feedback regulating loop, a singlechip circuit, a current detection circuit, a constant current regulating circuit and a current gear setting circuit;

the input end of the power supply main circuit is connected with an alternating current power supply;

the feedback regulation loop is respectively connected with the power supply main circuit and the singlechip circuit;

the constant current regulating circuit is respectively connected with the output end of the power supply main circuit, the singlechip circuit and the feedback regulating loop;

the current detection circuit is connected between the constant current regulation circuit and the singlechip circuit and is used for detecting output current Z;

The current gear setting circuit is connected with the singlechip and is used for setting a current gear X;

The singlechip circuit can output a first dimming signal and a second dimming signal and output the first dimming signal and the second dimming signal to a load through the constant current regulating circuit.

As one of the preferred embodiments of the present invention, the current gear setting circuit is provided as a dimming signal processing circuit connected to the single chip microcomputer circuit and the dimming system, respectively.

As one of the preferred embodiments of the present invention, the current gear setting circuit is configured as NFC circuits respectively connected to the single chip microcomputer circuits.

As one of the preferred embodiments of the present invention, the current gear setting circuit includes a dimming signal processing circuit and an NFC circuit, the dimming signal processing circuit is connected to the single chip circuit and the dimming system, respectively, and the NFC circuit is connected to the single chip circuit.

As one of the preferred embodiments of the present invention, the feedback regulation loop includes an operational amplifier U2A, a resistor R5-7, a resistor R9-11, a capacitor C2, a diode D5, and an optocoupler DU3, wherein the forward input terminal of the operational amplifier U2A is connected to one end of the resistor R5 and one end of the resistor R7, the other end of the resistor R7 is connected to the VCC terminal, the reverse input terminal of the operational amplifier U2A is connected to one end of the resistor R6, one end of the resistor R10, and one end of the capacitor C2, the other end of the capacitor C2 is connected to the cathode of the diode D5 and the output terminal of the operational amplifier U2A via the resistor R11, the anode of the diode D5 is connected to one end of the optocoupler DU3 light emitter, the other end of the optocoupler DU3 light emitter is connected to the VCC terminal via the resistor R9, one end of the optocoupler DU3 light receiver is connected to the power supply main circuit, the other end of the optocoupler DU3 light receiver is connected to the GND terminal, and the other end of the resistor R10 is connected to the GNS terminal.

As one of preferred embodiments of the present invention, the current detection circuit includes an operational amplifier U5, a resistor R8, resistors R21 to 22, and resistors R24 to 25, the forward input terminal of the operational amplifier U5 is connected to one end of the resistor R21 and one end of the resistor R22, respectively, the other end of the resistor R22 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to the output terminal of the power supply main circuit and to the inverting input terminal of the operational amplifier U5 and one end of the resistor R25 via the resistor R24, the other end of the resistor R25 is connected to the output terminal of the operational amplifier U5 and the monolithic circuit, respectively, the other end of the resistor R21 and the ground terminal of the operational amplifier U5 are connected to the GNS terminal, and the power supply terminal of the operational amplifier U5 is connected to the VCC terminal.

As one of the preferred embodiments of the invention, the constant current regulating circuit comprises a constant current chip U3, a MOS tube Q1, resistors R26-27, an inductor L1 and a diode D5, wherein one end of the resistor R27 is respectively connected with a power supply main circuit and the cathode of the diode D5, two ends of the resistor R27 are connected with the sampling end of the constant current chip U3, the source electrode of the MOS tube Q1 is connected with the power supply main circuit, the grid electrode of the MOS tube Q1 is connected with the output end of the constant current chip U3 through the resistor R26, the drain electrode of the MOS tube Q1 is connected with a load through the inductor L1, and the input end of the constant current chip U3 is connected with the singlechip.

As one of the preferred embodiments of the present invention, a current adaptive regulation circuit of an LED power supply further includes a first filter circuit connected between the single chip circuit and an input terminal of the constant current chip U3.

As one of the preferred embodiments of the present invention, the constant current adjusting circuit includes an operational amplifier U2B, resistors R12-16, capacitors C3-4 and a diode D6, the forward input terminal of the operational amplifier U2B is connected to one end of the resistor R12 and one end of the resistor R13, the other end of the resistor R13 is connected to the VCC terminal, the reverse input terminal of the operational amplifier U2B is connected to one end of the capacitor C3, one end of the capacitor C4, one end of the resistor R14 and one end of the resistor R16, the other end of the resistor R14 is connected to the output terminal of the power supply main circuit, the other end of the resistor R16 is connected to the cathode of the diode D6 and the output terminal of the operational amplifier U2B via a resistor R15, the anode of the diode D6 is connected to the feedback adjusting loop, and the other ends of the capacitor C3 and the resistor R12 are connected to the GNS terminal.

As one of the preferred embodiments of the present invention, a current adaptive regulation circuit of an LED power supply further includes a control circuit connected between the constant current regulation circuit and the single chip microcomputer circuit.

As one of the preferred embodiments of the present invention, the control circuit includes an operational amplifier U6, a resistor R19 and a capacitor C5, the forward input terminal of the operational amplifier U6 is connected to one end of the resistor R19 and one end of the capacitor C5, respectively, the other end of the resistor R19 is connected to the monolithic circuit, the reverse input terminal of the operational amplifier U6 is connected to the output terminal of the operational amplifier U6 and the constant current regulating circuit, respectively, the power supply terminal of the operational amplifier U6 is connected to the VCC terminal, and the ground terminal of the operational amplifier U6 and the other end of the capacitor C5 are connected to the GNS terminal.

The invention has the beneficial effects that: the current self-adaptive regulating circuit comprises a power supply main circuit, a feedback regulating loop, a singlechip circuit, a current detection circuit, a constant current regulating circuit and a current gear setting circuit; the input end of the power supply main circuit is connected with an alternating current power supply; the feedback regulation loop is respectively connected with the power supply main circuit and the singlechip circuit; the constant current regulating circuit is respectively connected with the output end of the power supply main circuit, the singlechip circuit and the feedback regulating loop; the current detection circuit is connected between the constant current regulation circuit and the singlechip circuit and is used for detecting output current Z; the current gear setting circuit is connected with the singlechip and is used for setting a current gear X; the singlechip circuit can output a first dimming signal and a second dimming signal and output the first dimming signal and the second dimming signal to a load through the constant current regulating circuit; the output current is detected in real time and compared with the set current gear, so that the current curve of any chip can be set with the current gear while the output current precision is ensured.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic block diagram of a first embodiment of a current adaptive regulation circuit for an LED power supply;

FIG. 2 is a schematic block diagram of a second embodiment of a current adaptive regulation circuit for an LED power supply;

FIG. 3 is a schematic block diagram of a third embodiment of a current adaptive regulation circuit for an LED power supply;

FIG. 4 is a functional block diagram of a fourth embodiment of a current adaptive regulation circuit for an LED power supply;

FIG. 5 is a first schematic circuit diagram of a current adaptive regulation circuit for an LED power supply;

FIG. 6 is a second schematic circuit diagram of a current adaptive regulation circuit for an LED power supply;

FIG. 7 is a schematic circuit diagram of a power supply main circuit;

FIG. 8 is a schematic circuit diagram of a feedback regulation loop;

FIG. 9 is a schematic circuit diagram of a single-chip microcomputer circuit;

Fig. 10 is a circuit schematic of the first embodiment of the constant current output circuit;

FIG. 11 is a schematic circuit diagram of a circuit detection circuit;

Fig. 12 is a circuit schematic of a second embodiment of the constant current output circuit;

Fig. 13 is a schematic circuit diagram of an NFC circuit;

FIG. 14 is a schematic circuit diagram of a first filter circuit;

FIG. 15 is a schematic circuit diagram of a control circuit;

FIG. 16 is a schematic circuit diagram of a second filter circuit;

fig. 17 is a flow chart of a method of current adaptive regulation of an LED power supply.

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the accompanying drawings are used to supplement the description of the written description so that one can intuitively and intuitively understand each technical feature and overall technical scheme of the present invention, but not to limit the scope of the present invention.

In the description of the present invention, plural means two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and the above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present invention and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

In the present invention, unless clearly defined otherwise, the terms "disposed," "mounted," "connected," and the like are to be construed broadly and may be connected directly or indirectly through an intermediary; the connecting device can be fixedly connected, detachably connected and integrally formed; may be a mechanical connection; may be a communication between two elements or an interaction between two elements. The specific meaning of the words in the invention can be reasonably determined by a person skilled in the art in combination with the specific content of the technical solution.

Referring to fig. 1 to 17, a current adaptive adjustment method of an LED power supply includes the steps of:

S1, setting a current gear X and an error Q;

s2, outputting a first dimming signal to the load, wherein the first dimming signal corresponds to the lowest brightness or the off brightness of the load;

S3, detecting the output current Z of the power supply, and comparing the current gear X with the output current Z;

And S4, outputting a second dimming signal to the load so that the current gear X outputs current Z=error Q.

① Referring to fig. 17, the control flow of the current adaptive adjustment method provided by the present invention is as follows: firstly, a current gear is set by using a current gear setting circuit 60 and is input into a single chip microcomputer circuit 30, the single chip microcomputer circuit 30 analyzes all received dimming signals, the set current gear is marked as X, the single chip microcomputer circuit 30 outputs a first dimming signal (PWM output signal or direct current output signal) corresponding to the lowest brightness or the off brightness to a constant current circuit regulating circuit 50 (wherein the lowest brightness refers to the state that a power supply cannot be turned on and can only be turned off, the off brightness refers to the state that the power supply is turned off), the first dimming signal and the second dimming signal are taken as PWM signals as examples for explanation, namely, the single chip microcomputer circuit 30 outputs the lowest brightness or the duty ratio Y% corresponding to the off brightness to the constant current circuit regulating circuit 50, the current detecting circuit 40 inputs the detected output current to the single chip microcomputer circuit 30, the detected output current is marked as Z, the single chip microcomputer circuit 30 compares the current gear X with the output current Z, judges whether a difference value is equal to a preset error Q, if the difference value is not equal to the error Q, the current is continuously increased on the basis of the current of the single chip microcomputer circuit 30, and the current is gradually increased to the current of the current duty ratio Z is continuously increased to the current of the single chip microcomputer circuit 30; note that, when the error Q is positive and negative, for example, when the error Q is 2mA, the difference between the current gear X and the output current Z is between +2ma and-2 mA may be determined that the adjustment is completed.

② As a first embodiment of the present invention, based on the embodiment of the current adaptive adjustment circuit shown in fig. 5, since the current adaptive adjustment circuit adjusts the dimming end of the constant current chip U3, that is, the minimum brightness corresponds to the maximum current; setting the current error to 2mA at first, if no over-current gear is currently set, setting the current gear to 800mA (corresponding to a duty ratio of 35%) and the duty ratio of the lowest brightness to 1% (corresponding to 20 mA) through the current gear setting circuit 60, outputting the duty ratio by the singlechip circuit 30 at each time in Y% increments, and comparing with the sampled output current Z, for example, sampling the output current z=20ma for the first time, wherein the current gear X-output current z=800 mA-20 ma=780 mA is not equal to 2mA, continuously increasing the duty ratio by the singlechip circuit 30 until the output current is increased to between 800mA-2 ma=798 mA and 800 ma+2ma=802 mA, and stopping increasing the duty ratio by the singlechip circuit 30 (reaching 35%); it should be noted that, if the first dimming signal corresponds to the minimum current when the load is at the lowest brightness or the off brightness, the second dimming signal is obtained by decrementing the first dimming signal; if the first dimming signal corresponds to the maximum current when the load is at the lowest brightness or the off brightness, the second dimming signal is obtained by increasing the first dimming signal.

③ As a second embodiment of the present invention, based on the first embodiment, if a current gear X1 is set currently and a new current gear X2 needs to be set again, the magnitudes of the current gear X2 and the previous current gear X1 are determined first, if the current gear X2> the previous current gear X1, the first dimming signal is a dimming signal corresponding to the previous current gear X1, that is, if the current gear X2< the previous current gear X1, the first dimming signal corresponds to the lowest brightness or the off brightness of the load; that is, when the current gear x1=800 mA is set currently and a new current gear x2=900 mA needs to be set, because the current gear X2> the current gear X1, the single-chip circuit 30 increases on the basis of the duty ratio of 35% corresponding to 800mA until the output current increases between 900mA-2 ma=898 mA and 900 ma+2ma=902 mA, and the single-chip circuit 30 stops increasing the duty ratio (up to 40%); if the current gear x1=800 mA is currently set and a new current gear x2=700 mA needs to be set, because the current gear X2 is smaller than the current gear X1, the single-chip microcomputer circuit 30 increases on the basis of the 1% duty ratio corresponding to the lowest brightness, and the single-chip microcomputer circuit 30 stops increasing the duty ratio (up to 30%) until the output current increases between 700mA-2 ma=698ma and 700 ma+2ma=702 mA.

④ Referring to fig. 1-16, a current adaptive regulation circuit of an LED power supply, to which the current adaptive regulation method is applied, includes a power supply main circuit 10, a feedback regulation loop 20, a singlechip circuit 30, a current detection circuit 40, a constant current regulation circuit 50, and a current gear setting circuit 60;

the input end of the power supply main circuit 10 is connected with an alternating current power supply;

the feedback regulation loop 20 is respectively connected with the power supply main circuit 10 and the singlechip circuit 30;

The constant current regulating circuit 50 is respectively connected with the output end of the power supply main circuit 10, the singlechip circuit 30 and the feedback regulating loop 20;

The current detection circuit 40 is connected between the constant current regulation circuit 50 and the singlechip circuit 30 and is used for detecting output current Z;

The current gear setting circuit 60 is connected with the singlechip circuit 30 and is used for setting a current gear X;

the singlechip circuit 30 can output a first dimming signal and a second dimming signal and output the first dimming signal and the second dimming signal to a load through the constant current adjusting circuit 50.

The working principle of the current self-adaptive regulating circuit provided by the invention is as follows:

Referring to fig. 5 to 7, in the power supply main circuit 10, L, N is connected to an EMI and rectifying circuit through a terminal, and after being processed by the EMI and rectifying circuit, the electrolytic capacitor EC1 is charged, and meanwhile, the resistor R2 is connected to a high-voltage starting circuit inside the switching power supply chip U1, so that the internal circuit of the switching power supply chip U1 is charged, and after reaching a starting voltage, the switching power supply chip U1 starts to start; the switch power supply chip U1 outputs a driving signal to conduct the NMOS tube Q2 through the resistor R3, the NMOS tube Q2 is conducted to drive the transformer T1, meanwhile, the resistor R4 converts the current flowing through the NMOS tube Q2 into a voltage signal and is connected to a power detection pin of the switch power supply chip U1, the transformer T1 rectifies and filters the electrolytic capacitor EC2, the electrolytic capacitor EC3 and the electrolytic capacitor EC4 through the rectifier diode D1, the rectifier diode D2 and the rectifier diode D3, and a power supply terminal V+ and a power supply terminal VCC and a power supply terminal VDD are respectively output to supply power to a rear-stage circuit, and the power supply terminal V+ and the power supply ground terminal V-can be connected with an LED lamp (load).

Referring to fig. 5 and 8, in the feedback regulation loop 20, the feedback regulation loop 20 includes an operational amplifier U2A, a resistor R5-7, a resistor R9-11, a capacitor C2, a diode D5, and an optocoupler DU3, wherein a forward input end of the operational amplifier U2A is connected to one end of the resistor R5 and one end of the resistor R7, respectively, a reverse input end of the operational amplifier U2A is connected to one end of the resistor R6, one end of the resistor R10, and one end of the capacitor C2, the other end of the capacitor C2 is connected to a cathode of the diode D5 and an output end of the operational amplifier U2A, an anode of the diode D5 is connected to one end of the optocoupler DU3, the other end of the optocoupler DU3 is connected to one end of the optocoupler DU3 is connected to the power supply main circuit 10, the other end of the optocoupler DU3 is connected to the GND end, and the other end of the resistor R5 and the other end of the resistor R10 are connected to the VCC end.

Specifically, the power supply terminal VCC is connected to the 3 rd pin of the operational amplifier U2 after being divided by the resistor R7 and the resistor R5 to generate the reference voltage VREF, the power supply terminal v+ is connected to the 2 nd pin of the operational amplifier U2 after being divided by the resistor R6 and the resistor R10, and is compared with the 3 rd pin of the operational amplifier U2, the 1 st pin output signal of the operational amplifier U2 after comparison is connected to the 2 nd pin of the photo coupler DU3, and the feedback pin of the power chip is controlled by the 4 th pin of the photo coupler DU3 to stabilize the output voltage v+; the 1 st pin of the photo coupler DU3 is connected to the power supply terminal VCC through a resistor R9, and the resistor R11 and the capacitor C2 are loop compensation of the operational amplifier U2A.

Referring to fig. 5 and 9-10, as a first embodiment of the constant current adjusting circuit 50, the constant current adjusting circuit 50 includes a constant current chip U3, a MOS transistor Q1, resistors R26-27, an inductor L1 and a diode D5, wherein one end of the resistor R27 is connected to the power supply main circuit 10 and the cathode of the diode D5, two ends of the resistor R27 are connected to the sampling end of the constant current chip U3, the source electrode of the MOS transistor Q1 is connected to the power supply main circuit 10, the gate electrode of the MOS transistor Q1 is connected to the output end of the constant current chip U3 through the resistor R26, the drain electrode of the MOS transistor Q1 is connected to the load through the inductor L1, and the input end of the constant current chip U3 is connected to the single chip circuit 30; the power supply terminal V+ is connected to the terminal LED+ through a resistor R8, the 17 th pin output driving signal of the singlechip U4 is connected to the 3 rd pin of the constant current chip U3 after being filtered through a resistor R19 and a capacitor C5, the 5 th pin output driving signal of the constant current chip U3 is conducted with an NMOS tube Q1 through a resistor R26 after being processed by the constant current chip U3, one end of an inductor L1 is connected to the GNS end through a resistor R27 after the NMOS tube Q1 is conducted, and the other end of the inductor L1 is connected to the terminal LED-, so that a lamp is lighted; the current passes through a resistor R8 and a resistor R27, voltage drop signals are generated on the resistor R8 and the resistor R27, and the voltage drop signals at two ends of the resistor R8 are respectively connected to the 1 st pin of the constant current chip U3 and the 2 nd pin of the constant current chip U3 for current detection; that is, the dimming end of the constant current chip U3 is regulated.

Referring to fig. 6 and 12, as a second embodiment of the constant current adjusting circuit 50, the constant current adjusting circuit 50 includes an operational amplifier U2B, a resistor R12-16, a capacitor C3-4, and a diode D6, wherein a forward input terminal of the operational amplifier U2B is connected to one end of the resistor R12 and one end of the resistor R13, respectively, the other end of the resistor R13 is connected to the VCC terminal, a reverse input terminal of the operational amplifier U2B is connected to one end of the capacitor C3, one end of the capacitor C4, one end of the resistor R14, and one end of the resistor R16, respectively, the other end of the resistor R14 is connected to an output terminal of the power supply main circuit 10, the other end of the resistor R16 is connected to the singlechip circuit 30, the other end of the capacitor C4 is connected to a cathode of the diode D6 and an output terminal of the operational amplifier U2B via a resistor R15, an anode of the diode D6 is connected to the feedback adjusting loop 20, and the other end of the capacitor C3 and the other end of the resistor R12 are connected to the GNS terminal; namely, the constant current loop in the feedback regulation loop 20 is regulated, the voltage drop signal on the resistor R8 is fed into the positive input end of the operational amplifier U2B after being divided by the resistor R14 and the resistor R16, and meanwhile, the voltage drop signal is also controlled to be output to the constant current regulation circuit 50 for constant current regulation by the singlechip circuit 30 according to the output current fed back by the current detection circuit 40 through the control circuit 80 and the singlechip circuit 30.

Referring to fig. 5 to 6 and 11, in the current detection circuit 40, the current detection circuit 40 includes an operational amplifier U5, a resistor R8, a resistor R21 to 22, and a resistor R24 to 25, wherein a forward input terminal of the operational amplifier U5 is connected to one end of the resistor R21 and one end of the resistor R22, respectively, the other end of the resistor R22 is connected to one end of the resistor R8, the other end of the resistor R8 is connected to an output terminal of the power supply main circuit 10 and is connected to an inverting input terminal of the operational amplifier U5 and one end of the resistor R25 via the resistor R24, the other end of the resistor R25 is connected to an output terminal of the operational amplifier U5 and the singlechip circuit 30, the other end of the resistor R21 and a ground terminal of the operational amplifier U5 are connected to the GNS terminal, and a power supply terminal of the operational amplifier U5 is connected to the VCC terminal; specifically, the voltage drop signals at two ends of the resistor R27 are respectively connected to the 1 st pin of the operational amplifier U5 and the 3 rd pin of the operational amplifier U5 through the resistor R22 and the resistor R24, amplified by the operational amplifier U5, filtered by the 4 th pin of the operational amplifier U5 through the resistor R23 and the capacitor C7, and then connected to the 16 th pin of the singlechip U4 for detection; the resistor R21, the resistor R22, the resistor R24, the resistor R25 and the operational amplifier U5 form a differential amplifier structure, and corresponding amplification factors can be obtained by setting parameters of the resistor R21, the resistor R22, the resistor R24 and the resistor R25.

Referring to fig. 5-6 and 13, the antenna P1 is connected to the 2 nd pin and the 3 rd pin of the NFC chip U3, after being processed by the NFC chip U3, the 5 th pin and the 6 th pin of the NFC chip U3 output corresponding I2C signals to the 2 nd pin and the 3 rd pin of the single chip microcomputer U1, the single chip microcomputer U1 interprets the I2C signals, and parameters can be set by sensing the antenna P1 through electronic equipment; when parameters are set through the system, the dimming system sends instructions, the instructions are processed by the dimming signal processing circuit and then are respectively connected to the 7 th pin of the singlechip U4 and the 8 th pin of the singlechip U4, and the singlechip U5 is internally analyzed and then carries out operation of corresponding instructions.

Referring to fig. 1 and 3, as a first embodiment of the current-stage setting circuit 60, the current-stage setting circuit 60 is provided as a dimming signal processing circuit 61 connected to the single-chip microcomputer circuit 30 and the dimming system, respectively; referring to fig. 2 and 4, as a second embodiment of the current gear setting circuit 60, the current gear setting circuit 60 is provided as NFC circuits 62 respectively connected with the single chip microcomputer circuits 30; referring to fig. 5 and 6, as a third embodiment of the current gear setting circuit 60, the current gear setting circuit 60 includes a dimming signal processing circuit 61 and an NFC circuit, the dimming signal processing circuit 61 is connected to the single chip microcomputer circuit 30 and the dimming system, and the NFC circuit 62 is connected to the single chip microcomputer circuit 30.

The current self-adaptive regulating circuit of the LED power supply further comprises a first filter circuit 70 connected between the singlechip circuit 30 and the input end of the constant-current chip U3.

Preferably, the first filter circuit 70 includes a resistor R19 and a capacitor C5, wherein one end of the resistor R19 is connected with the singlechip circuit 30, the other end is respectively connected with one end of the capacitor C5 and the input end of the constant current chip U3, and the other end of the capacitor C5 is grounded; the second filter circuit 90 includes a resistor R23 and a capacitor C7, where one end of the resistor R23 is connected to the current detection circuit 40, the other end of the resistor R23 is connected to one end of the capacitor C7 and the singlechip circuit 30, and the other end of the capacitor C7 is connected to the GNS end.

The current self-adaptive regulating circuit of the LED power supply further comprises a control circuit 80 connected between the constant current regulating circuit 50 and the singlechip circuit 30.

As a preferred embodiment of the control circuit 80, the control circuit 80 includes an operational amplifier U6, a resistor R19 and a capacitor C5, wherein a forward input terminal of the operational amplifier U6 is connected to one end of the resistor R19 and one end of the capacitor C5, respectively, the other end of the resistor R19 is connected to the single chip microcomputer circuit 30, a reverse input terminal of the operational amplifier U6 is connected to an output terminal of the operational amplifier U6 and the constant current regulating circuit 50, a power supply terminal of the operational amplifier U6 is connected to a VCC terminal, and a ground terminal of the operational amplifier U6 and the other end of the capacitor C5 are connected to a GNS terminal.

The invention has the advantages that: the output current is detected in real time and compared with the set current gear, so that the current curve of any chip can be set with the current gear while the output current precision is ensured.

Of course, the present application is not limited to the above-described embodiments, and those skilled in the art can make equivalent modifications and substitutions without departing from the spirit of the present application, and these equivalent modifications and substitutions are included in the scope of the present application as defined in the appended claims.