CN114928909A - Self-adaptive dimming voltage-control energy supply circuit - Google Patents

Abstract

The invention relates to the technical field of load driving, and discloses a self-adaptive dimming voltage-controlled energy supply circuit which comprises a voltage control module, a load, a current regulation module and a signal sampling processing feedback dynamic regulation module, wherein the voltage control module is provided with an output voltage regulation feedback port, the signal sampling processing feedback dynamic regulation module is used for carrying out signal processing on a sampling signal from a load negative electrode end according to a dimming signal from the current regulation module to obtain a mixed signal of which the frequency component is in nonlinear negative correlation with the load current after dimming, and the mixed signal and the sampling signal from a load positive electrode end are superposed and fed into the feedback port together, so that the voltage control module carries out dynamic regulation on the output voltage according to the fed signal, and the difference value between the output voltage of the voltage control module and the voltage at two ends of the load is always in a constant state preset by a circuit in the whole dimming process, thereby effectively improving the dimming performance.

Description

An adaptive dimming voltage control power supply circuit

technical field

The invention belongs to the technical field of load driving, and in particular, relates to an adaptive dimming voltage control energy supply circuit.

Background technique

At present, high PFC (Power Factor Correction, power factor correction, refers to the relationship between effective power and total power consumption, that is, the ratio of effective power divided by total power consumption) is required for dimming or dimming and color matching. And for constant current applications without flicker, most of them adopt the method of first AC to DC and then DC to DC to meet the certification requirements, especially for constant current applications with power greater than 20W. The advantage of this method is that both the pre-stage circuit scheme and the post-stage circuit scheme are relatively mature, with stable performance, and there are many alternative reference schemes, but its shortcomings are also very obvious, such as EMC (Electromagnetic Compatibility, electromagnetic compatibility, refers to equipment or The ability of the system to operate satisfactorily in its electromagnetic environment without causing intolerable electromagnetic interference to any equipment in its environment) is difficult to handle, the cost of solving EMC problems is high, the size is not easy to miniaturize, and the room for improvement in dimming performance is limited. and many more. If the project requires some additional index requirements, the cost of the drive will easily increase exponentially, such as high PFC, THD (Total Harmonic Distortion, total harmonic distortion) less than 10%, no stroboscopic, high efficiency, less than 1 % dimming depth, small size, with dial code current adjustment and with independent isolated power supply interface, etc., it is difficult to achieve a proper balance between performance and cost in the design of the drive circuit.

In addition, there is a contradiction that is becoming more and more prominent, that is, the contradiction between the current market demand for intelligent power supply integration and the stagnation of driving topology technology. The biggest push in the current market is the Internet of Things, which requires lamps to have remote networked intelligent control capabilities, so it is necessary to attach a networkable control device or sensor to the driving power supply, which will become more and more demanding on power supply, such as outdoor lighting. Some monitoring points, lamps and sensors, cameras and communication devices are an integrated structure, which requires the power supply to supply power to lamps and other equipment at the same time. In commercial or indoor lighting scenarios, sensors and communication connection modules are attached to each luminaire, so that each luminaire can not only have intelligent control capabilities that can be remotely networked, but also become a lighting that can operate independently. point. This demand trend will only become stronger in the future. From this perspective, the driving power supply is viewed separately. For example, in common lighting projects with WIFI (Wireless Fidelity) dimming and color matching functions, its driving The power supply includes a constant voltage part from AC to DC, two constant current parts from DC to DC, and an auxiliary constant voltage power supply part from DC to DC. There are 4 switching power supplies required, and there are lighting projects with device volume. The defects of large and required switching power supply, if an independent isolated power supply is to be added to this lighting project, then an AC to DC power supply must be added. For a tens of watt lamps, these Everything is stuffed into a shell, the size is natural, what is more troublesome is that there are so many switching power supplies inside, so the EMC and interference will become very bad, even if it can pass the certification, it will be obtained after adding a lot of cost. Come, and there is no suitable technology to solve this problem on the market at present, and it has become a common pain point in the industry.

SUMMARY OF THE INVENTION

In order to solve the problem that it is difficult for the existing driving circuit to meet the requirements of stable and non-fluctuation of the output voltage of the pre-stage and the output current of the post-stage and high efficiency of the operation of the post-stage circuit at a low cost during the dimming process, the purpose of the present invention is to provide an adaptive dimming. The controlled voltage energy supply circuit can make the output voltage of the front-stage circuit and the output current of the latter-stage circuit stable without fluctuation during the whole dimming process, and keep the latter-stage circuit in a high-efficiency working state, which can effectively improve the The performance of dimming is convenient for practical application and promotion.

The technical scheme adopted by the present invention is: an adaptive dimming voltage control energy supply circuit, comprising a voltage control module, a load, a current adjustment module and a signal sampling processing feedback dynamic adjustment module, wherein the voltage control module has an output voltage adjustment feedback port, and the load is a light-emitting lamp;

The voltage control module is used to convert the input voltage into a DC voltage and output it;

The positive terminal of the load is connected to the voltage output terminal of the voltage control module, the negative terminal of the load is connected to one end of the current regulation module, and the other end of the current regulation module is grounded;

the current adjustment module, configured to adjust the magnitude of the current flowing through the load according to an external dimming signal, so as to make the voltage across the load match the voltage of the voltage output terminal;

The first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the voltage output terminal, the second signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the negative terminal, and the signal sampling processing feedback dynamic adjustment module is connected to the negative terminal. The communication terminal of the adjustment module is connected to the current adjustment module, and the signal output terminal of the signal sampling processing feedback dynamic adjustment module is connected to the output voltage adjustment feedback port;

The signal sampling processing feedback dynamic adjustment module is configured to perform signal processing on the second sampling signal from the negative terminal according to the dimming signal from the current adjustment module to obtain a frequency component and the load after dimming a mixed signal with a nonlinear negative correlation of the magnitude of the current, and the mixed signal and the first sampling signal from the voltage output terminal are superimposed and fed into the output voltage adjustment feedback port, so that the voltage control module can adjust the output voltage according to the input signal. The output voltage is dynamically adjusted, so that in the entire dimming process, the difference between the output voltage of the voltage control module and the voltage at both ends is always in a constant state preset by the circuit.

Based on the above-mentioned contents of the invention, a load driving solution for feedback control of output voltage based on a dimming signal and a sampling signal at both ends of the load is provided, that is, it includes a voltage control module, a load, a current adjustment module and a signal sampling processing feedback dynamic adjustment module, The voltage control module has an output voltage adjustment feedback port, and the signal sampling processing feedback dynamic adjustment module is configured to perform signal processing on the second sampling signal from the negative terminal of the load according to the dimming signal from the current adjustment module , obtain a mixed signal whose frequency component is non-linearly negatively correlated with the magnitude of the load current after dimming, and superimpose the mixed signal with the first sampling signal from the positive terminal of the load and feed it into the output voltage adjustment feedback port, so that all The voltage control module dynamically adjusts the output voltage according to the input signal, so that in the entire dimming process, the difference between the output voltage of the voltage control module and the voltage at both ends of the load is always in a constant state preset by the circuit, and thus can be The output voltage of the pre-stage circuit and the output current of the post-stage circuit are both stable without fluctuation, and the post-stage circuit is always in a high-efficiency working state, which effectively improves the performance of dimming, and is convenient for practical application and promotion.

In a possible design, the voltage control module adopts a switching power supply including an inductive element circuit unit and a switch control circuit unit, wherein the inductive element circuit unit includes an inductor and/or a transformer, and the switch control circuit unit The controlled end is used as the output voltage adjustment feedback port.

In a possible design, when the inductive element circuit unit includes a transformer, the voltage-controlled energy supply circuit further includes at least one auxiliary winding module;

The auxiliary winding module includes a crystal diode, an electrolytic capacitor and an auxiliary winding, wherein the auxiliary winding and the main winding of the transformer are in the same magnetic circuit, and the anode of the crystal diode is connected to one end of the auxiliary winding, so the auxiliary winding is in the same magnetic circuit as the main winding of the transformer. The cathode of the crystal diode is connected to the anode of the electrolytic capacitor, the cathode of the electrolytic capacitor is grounded, and the anode of the electrolytic capacitor is used as the power supply output end of the auxiliary winding module to which it belongs;

The third signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the power supply output terminal of an auxiliary winding module in the at least one auxiliary winding module;

The signal sampling processing feedback dynamic adjustment module is further configured to superimpose the third sampling signal from the power supply output end of the certain auxiliary winding module, the mixed signal and the first sampling signal to feed into the output voltage Adjust the feedback port, so that in the process of dynamically adjusting the output voltage according to the input signal, the voltage control module makes the switch control circuit unit enter the following intermittent mode when the dimming depth is found to be lower than the preset depth threshold. Energy supply mode: if the voltage value of the third sampling signal is lower than the preset voltage threshold and is in a downward trend, the energy supply is increased by shortening the interval between two adjacent energy supply pulses. If the voltage value is in an upward trend and is close to the preset voltage threshold, the energy supply is reduced by extending the interval between two adjacent energy supply pulses, so that each auxiliary winding module can continue to stably operate under the cooperation of the corresponding electrolytic capacitors. External energy supply.

In a possible design, the switching power supply adopts an isolated flyback power supply topology, a boost power supply topology or a buck power supply topology.

In a possible design, the current regulation module includes an integrated current stabilization circuit unit and a logic judgment unit, wherein the current stabilization circuit unit is used to draw the current flowing through the load to ground, and the logic judgment unit The unit is used to adjust the magnitude of the current flowing through the load according to the external dimming signal.

In a possible design, the signal sampling processing feedback dynamic adjustment module is further configured to trigger sending an alarm signal to the logic judgment unit when the second sampling signal is found to be abnormal, so that the logic judgment unit receives When the alarm signal is activated, the magnitude of the current flowing through the load is adjusted to zero, so as to realize the purpose of protecting the load by turning off the current.

In a possible design, the signal sampling processing feedback dynamic adjustment module includes a signal sampling trimming circuit unit, a signal processing circuit unit and a feedback circuit unit, wherein the signal input terminal of the signal sampling trimming circuit unit serves as the signal The second signal sampling terminal of the sampling processing feedback dynamic adjustment module is connected to the negative terminal, the signal output terminal of the signal sampling and trimming circuit unit is connected to the signal input terminal of the signal processing circuit unit, and the signal output terminal of the signal processing circuit unit is connected. The second signal input terminal of the feedback circuit unit is connected to the second signal input terminal of the feedback circuit unit. The communication terminal of the signal processing circuit unit is connected to the current adjustment module as the communication terminal of the signal sampling processing feedback dynamic adjustment module. A signal input terminal is connected to the voltage output terminal as the first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module, and the signal output terminal of the feedback circuit unit is used as the signal output terminal of the signal sampling processing feedback dynamic adjustment module connecting to the output voltage adjustment feedback port;

The signal sampling and trimming circuit unit is configured to trim the second sampled signal from the negative terminal, and send the trimmed signal obtained by processing to the signal processing circuit unit, wherein the trimming process includes There are filtering processing, voltage dividing and voltage limiting processing and integral processing performed in sequence;

The signal processing circuit unit is configured to perform signal processing on the trimmed signal according to the dimming signal from the current adjustment module to obtain a mixture of a frequency component and a non-linear negative correlation of the load current after dimming signal, and send the mixed signal into the feedback circuit unit;

The feedback circuit unit is configured to superimpose the mixed signal and the first sampling signal from the voltage output terminal to feed the output voltage adjustment feedback port.

In a possible design, according to the dimming signal from the current adjustment module, signal processing is performed on the trimmed signal to obtain a mixed signal whose frequency component is non-linearly negatively correlated with the magnitude of the load current after dimming, include:

According to the dimming signal from the current adjustment module, the attenuation processing is performed on some frequency components in the trimmed signal in which the attenuation degree is nonlinearly negatively correlated with the magnitude of the load current after dimming, and a frequency component and dimming are obtained. After the load current size is non-linear and negatively correlated mixed signal, and when the load current size after the dimming is in the dimmed state, all frequency components in the trimmed signal are completely attenuated, so that the feedback circuit is sent to the feedback circuit. The unit has no signal output.

In a possible design, sending the mixed signal into the feedback circuit unit includes:

After the mixed signal is integrated at least once, it is amplified and sent to the feedback circuit unit.

In a possible design, the signal sampling mode of the signal sampling and trimming circuit unit is a direct sampling mode or an indirect sampling mode, wherein the direct sampling mode includes a resistor divider voltage divider sampling mode, a triode divider current sampling mode, an operational amplifier Non-destructive sampling method, optocoupler isolation sampling method and/or digital sampling method based on microprocessor MCU chip, and the indirect sampling method refers to the sampling method in which the voltage is increased by the voltage superposition processing technology.

The beneficial effects of the present invention are:

(1) The present invention provides a load driving scheme for feedback control of the output voltage based on the dimming signal and the sampling signal at both ends of the load, that is, it includes a voltage control module, a load, a current adjustment module and a signal sampling processing feedback dynamic adjustment module , wherein the voltage control module has an output voltage adjustment feedback port, and the signal sampling processing feedback dynamic adjustment module is used to signal the second sampling signal from the negative terminal of the load according to the dimming signal from the current adjustment module process to obtain a mixed signal whose frequency component is nonlinearly negatively correlated with the magnitude of the load current after dimming, and superimpose the mixed signal with the first sampling signal from the positive terminal of the load and feed it into the output voltage adjustment feedback port, so that The voltage control module dynamically adjusts the output voltage according to the input signal, so that in the entire dimming process, the difference between the output voltage of the voltage control module and the voltage at both ends of the load is always in a constant state preset by the circuit, and then It can realize that the output voltage of the pre-stage circuit and the output current of the post-stage circuit are stable without fluctuation, and at the same time, the post-stage circuit is always in a high-efficiency working state, which can effectively improve the performance of dimming, and is convenient for practical application and promotion;

(2) It can achieve the purpose of precise dimming, which can be compatible with a wider dimming frequency range, and can achieve ultra-low depth brightness, which can reach the industry's highest depth of less than 1/1,000. The dimming experience has been greatly improved;

(3) It can have a wider power application range, that is, compared with the solution of using DC to DC, the range of output power can be increased by 2-3 times without increasing the cost;

(4) It can have a smaller volume, that is, because the post-stage circuit adopts non-inductive technology, it has obvious advantages in volume. Compared with the same solution on the market, the volume can be reduced by more than 20%;

(5) It can have excellent EMC characteristics, that is, because the post-stage circuit adopts non-inductive technology, when only a single-stage power supply structure is used to meet PFC and THD, the EMC performance is excellent, regardless of internal interference or external radiation interference. , which are obviously better than the solutions on the market;

(6) When the voltage control power supply circuit is in deep dimming or even in standby, each auxiliary winding can still maintain a good output capability, so that other control logic circuits can continue to operate. For projects with integrated functions, It can greatly reduce the cost and simplify the circuit design, and also make the power density of the drive become higher, the efficiency is higher, and the application is more flexible.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a voltage-controlled energy supply circuit provided by the present invention.

FIG. 2 is a schematic structural diagram of a voltage-controlled energy supply circuit using an indirect sampling method provided by the present invention.

3 is a schematic structural diagram of a voltage-controlled energy supply circuit in which the switching power supply provided by the present invention adopts a flyback power supply topology structure.

4 is a schematic structural diagram of a voltage-controlled energy supply circuit in which the switching power supply provided by the present invention adopts a boost power supply topology structure.

5 is a schematic structural diagram of a voltage-controlled energy supply circuit in which the switching power supply provided by the present invention adopts a step-down power supply topology.

FIG. 6 is a schematic structural diagram of a voltage-controlled energy supply circuit with an auxiliary winding module provided by the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted here that, although the description of these embodiments is for helping understanding of the present invention, it does not constitute a limitation of the present invention. Specific structural and functional details disclosed herein are merely illustrative of example embodiments of the present invention. The present invention, however, may be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

It should be understood that although the terms first and second, etc. may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another. For example, a first object could be referred to as a second object, and similarly a second object could be referred to as a first object, without departing from the scope of example embodiments of this invention.

It should be understood that the term "and/or" that may appear in this document is only an association relationship for describing associated objects, indicating that there may be three kinds of relationships, for example, A and/or B, which may indicate: the existence of A, There are three situations such as B alone or A and B at the same time; for the term "/and" that may appear in this article, it is to describe another related object relationship, indicating that there can be two relationships, for example, A/ and B, It can be expressed as: the existence of A alone or the existence of A and B at the same time; in addition, for the character "/" that may appear in this article, it generally means that the related objects before and after are an "or" relationship.

Example 1

As shown in FIG. 1 , the voltage control energy supply circuit provided by this embodiment and adaptive dimming includes, but is not limited to, a voltage control module, a load, a current regulation module, and a signal sampling processing feedback dynamic regulation module, wherein the said The voltage control module has an output voltage adjustment feedback port FB, and the load is a light-emitting lamp; the voltage control module is used to convert the input voltage into a DC voltage and output it; the positive terminal of the load is connected to the voltage control module The voltage output terminal V0, the negative terminal V1 of the load is connected to one end of the current regulation module, and the other end of the current regulation module is grounded; the current regulation module is used to adjust the current flow through the load according to the external dimming signal The current size of the load is adjusted to make the voltage across the load match the voltage of the voltage output terminal V0; the first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the voltage output terminal V0, so The second signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the negative terminal V1, the communication terminal of the signal sampling processing feedback dynamic adjustment module is connected to the current adjustment module, and the signal sampling processing feedback dynamic adjustment module is connected to the current adjustment module. The signal output terminal is connected to the output voltage adjustment feedback port FB; the signal sampling processing feedback dynamic adjustment module is used to sample the second sample from the negative terminal V1 according to the dimming signal from the current adjustment module The signal is processed to obtain a mixed signal whose frequency component is non-linearly negatively correlated with the magnitude of the load current after dimming, and the mixed signal and the first sampling signal from the voltage output terminal V0 are superimposed and fed into the output. The voltage adjustment feedback port FB, so that the voltage control module can dynamically adjust the output voltage according to the input signal, so that in the whole dimming process (ie, the dimming depth is from 0% to 100%), the output of the voltage control module The difference between the voltage and the voltage at both ends is always in a constant state preset by the circuit.

As shown in FIG. 1 , in the specific structure of the voltage control power supply circuit, the voltage control module may, but is not limited to, use a switch including an inductive element circuit unit (represented by HP in the drawings) and a switch control circuit unit A power supply, wherein the inductive element circuit unit includes but is not limited to an inductor and/or a transformer, and the controlled end of the switch control circuit unit serves as the output voltage adjustment feedback port FB. The switching power supply can, but is not limited to, use existing various buck, boost or buck-boost circuits that implement flyback/forward with the output voltage adjustment feedback port FB, regardless of high PFC applications Whether it is a low PFC application, an isolated application or a non-isolated application, and whether the power range is high power or low power, as long as it has the output voltage adjustment feedback port FB, it can be linked with the current adjustment module of the subsequent stage to realize the corresponding voltage Control application. The input voltage is represented by VIN in the drawings, which may be an AC voltage or a DC voltage. The switch control circuit unit may, but is not limited to, use an existing circuit structure based on a control chip, a switch tube, a drive circuit, etc. to realize the function of dynamically adjusting the output voltage according to the feed signal. In addition, the voltage output terminal V0 of the voltage control module can be specifically connected to the positive terminal of the load through a bus bar; and during the entire dimming process, the output voltage of the voltage control module and the voltage at both ends are different from each other. The specific appearance that the difference value is always in the constant state preset by the circuit is: in the whole dimming process, the output voltage of the voltage control module is stable and has no fluctuation (that is, including stable rise, stable fall and stable maintenance), the current adjustment The output current of the module is stable without fluctuation (that is, including stable rising, stable falling and stable maintenance), and the current regulation module is in a high-efficiency working state (that is, the negative terminal V1 will always be in a low-voltage state, and the internal power dissipation is low. , which can work efficiently).

The load may specifically include various linear loads or non-linear loads that require constant current operation, such as light-emitting lamps such as LED (Light-Emitting Diode, light-emitting diode) lamps, and the voltage across the load is the voltage output. The voltage difference between the terminal V0 and the negative terminal V1, the voltage between the two ends can vary from a few volts at a low voltage to a few hundred volts at a high voltage, and the current flowing through the load can be several milliamps to several amperes. The operating power can be from a few watts to several hundred watts. In addition, if the light-emitting lamp is replaced with a battery, a heating wire, a pure resistance, etc., other voltage-controlled energy supply circuits for adaptive current regulation can also be obtained.

The current regulation module specifically includes, but is not limited to, an integrated current stabilization circuit unit and a logic judgment unit, wherein the current stabilization circuit unit is used to draw the current flowing through the load to the ground, and the logic judgment unit is used to The magnitude of the current flowing through the load is adjusted according to the external dimming signal, so that various protections required for dimming and the constant current operation of the load can be taken into account. Since the negative terminal V1 is a node with voltage to ground, and its voltage value is the difference between the voltage of the voltage output terminal V0 minus the voltage across the load, it can directly reflect the current voltage across the load. Matching with the voltage of the voltage output terminal V0, for example, when the voltage of the voltage output terminal V0 is greater than the voltage across the load, then the voltage of the negative terminal V1 is also greater, and when the voltage When the voltage of the output terminal V0 is equal to the voltage of both ends of the load, then the voltage of the negative terminal V1 is approximately equal to 0V (at this time, the voltage of the two ends of the load matches the voltage of the voltage output terminal V0, that is, to achieve load matching). In addition, the dimming signal may be, but is not limited to, an analog signal, a digital signal or a PWM signal, and the current stabilization circuit unit may be implemented by using an existing adjustable constant current circuit.

The signal sampling processing feedback dynamic adjustment module specifically includes but is not limited to a signal sampling trimming circuit unit, a signal processing circuit unit and a feedback circuit unit, wherein the signal input terminal of the signal sampling trimming circuit unit is used as the signal sampling processing feedback The second signal sampling terminal of the dynamic adjustment module is connected to the negative terminal V1, the signal output terminal of the signal sampling and trimming circuit unit is connected to the signal input terminal of the signal processing circuit unit, and the signal output terminal of the signal processing circuit unit is connected to The second signal input end of the feedback circuit unit, the communication end of the signal processing circuit unit is connected to the current adjustment module as the communication end of the signal sampling processing feedback dynamic adjustment module, and the first signal of the feedback circuit unit The input terminal is connected to the voltage output terminal V0 as the first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module, and the signal output terminal of the feedback circuit unit is connected as the signal output terminal of the signal sampling processing feedback dynamic adjustment module. The output voltage adjustment feedback port FB; the signal sampling and trimming circuit unit is used for trimming the second sampling signal from the negative terminal V1, and sending the trimmed signal obtained by processing into the signal processing circuit unit, wherein the trimming processing includes but is not limited to filtering processing, voltage dividing and voltage limiting processing, integration processing, etc. performed in sequence; the signal processing circuit unit is configured to optical signal, perform signal processing on the trimmed signal to obtain a mixed signal whose frequency component is non-linearly negatively correlated with the magnitude of the load current after dimming, and send the mixed signal into the feedback circuit unit; the feedback circuit a unit for superimposing the mixed signal and the first sampling signal from the voltage output terminal V0 and feeding the mixed signal into the output voltage adjustment feedback port FB.

The signal sampling mode of the signal sampling and trimming circuit unit is a direct sampling mode or an indirect sampling mode. The direct sampling methods include, but are not limited to, resistor divider voltage divider sampling mode, triode divider current sampling mode, operational amplifier lossless sampling mode, optocoupler isolation sampling mode, and/or digital sampling based on MCU (Microcontroller Unit, micro control unit) chips. The method, etc., can be applied to the situation when the voltage of the negative terminal V1 is relatively high, so that even after the voltage dividing and current dividing process, there is still a relatively high voltage component to satisfy the subsequent trimming process. The indirect sampling method refers to the sampling method in which the voltage is increased by the voltage superposition processing technology, that is, for the scenario where the voltage of the negative terminal V1 is low, it is considered that the voltage component after direct sampling cannot meet the trimming processing of the subsequent circuit, so It is necessary to superimpose a fixed voltage Vg on the basis of the voltage of the negative terminal V1. The voltage Vg can be set according to the actual application. Specifically, it can be set by a Zener diode, a triode or even an LDO (Low Dropout Regulator, linear voltage regulator circuit) Various types of circuits that can realize constant voltage output such as voltage regulators are obtained by combining the voltage of the voltage output terminal V0; as shown in FIG. 2, the final output voltage signal Vx of the voltage superposition circuit unit is equal to the voltage of the negative terminal V1. and the sum of the voltage Vg. Therefore, regardless of the direct sampling method or the indirect sampling method, the voltage signal of the negative terminal V1 can be accurately collected in the end.

Since the load is working in a stable constant current state when it is not dimming, that is, the voltage across the load is also in a constant state. If it is described in detail as the load of the LED lamp, it is the constant current of the LED lamp. There is no stroboscopic, so it can be concluded that when the entire voltage control power supply circuit is stable, the voltage of the negative terminal V1 is also a relatively stable value, that is, the waveform should be the ripple voltage of the voltage output terminal V0 minus all The result of the voltage across the load, wherein, for a single-stage high PFC project, the ripple in the ripple voltage is the power frequency ripple, and if it is a two-stage topology or a low PFC structure, the ripple is is the DC voltage. At the same time, during the dimming process, the voltage of the negative terminal V1 will superimpose a high-frequency component on the basis of the waveform without dimming, and this high-frequency component is related to the PWM pulse frequency of the dimming signal (generally several KHz to tens of KHz) is consistent, at this time the voltage of the negative terminal V1 consists of three components: the ripple voltage of the voltage output terminal V0, the voltage across the load and the high frequency component; As the dimming depth is different, the ripple in the ripple voltage will change accordingly, and the voltage across the load will also be affected by this. In order to ensure the continuity and consistency of the matching between the ripple waveform voltage of the voltage output terminal V0 and the voltage across the load under different dimming depths, it is necessary to perform a series of trimming processes on the sampled signal waveforms. Filtering processing (that is, removing interference signals and some high-frequency components); followed by voltage division and voltage limiting processing (that is, the voltage division is for the convenience of circuit processing, and the voltage limiting is to deal with the voltage of the negative terminal V1 is too high. The damage of the circuit, for example, the voltage of the negative terminal V1 will become very high when the load is abnormal); the last is integral processing (that is, the influence of the power frequency ripple is removed).

Considering that the voltage signal of the negative terminal V1 will become extremely complex and changeable during dimming, and is directly related to the dimming signal, in order to make the voltage across the load exactly match the voltage output terminal V0 voltage, it is necessary to attenuate a part of the frequency component of the current trimmed signal according to the dimming signal to ensure that the mixed signal given to the feedback circuit unit will not be distorted and overshoot. For the dimming signal, perform signal processing on the trimmed signal to obtain a mixed signal whose frequency component is non-linearly negatively correlated with the magnitude of the load current after dimming, including but not limited to: For the dimming signal, perform attenuation processing on some frequency components in the trimmed signal in which the attenuation degree is nonlinear and negatively correlated with the magnitude of the load current after dimming, and obtain a frequency component with a nonlinear and negative correlation with the magnitude of the load current after dimming. mixed signals, and when the magnitude of the load current after the dimming is in a dimming state, complete attenuation processing is performed on all frequency components in the trimmed signal, so that no signal is output to the feedback circuit unit. In addition, specifically, sending the mixed signal to the feedback circuit unit includes but is not limited to: after performing at least one integration process on the mixed signal, amplifying (that is, performing a signal amplification process on the signal obtained by the integration process again) ) into the feedback circuit unit, wherein, the purpose of the at least one integration process is to ensure the integrity and dynamics of the mixed signal, and at the same time, it can also prevent signal distortion and overshoot, which is the entire voltage-controlled energy supply circuit. Stable key point. In addition, before performing signal processing on the trimmed signal, the signal processing circuit unit may also perform current limiting and integration processing on the trimmed signal, that is, since the voltage and current of the negative terminal V1 vary in amplitude And the complexity of the waveform, it is necessary to further eliminate the interference clutter and abnormal waveforms thoroughly to prepare for the next signal processing.

In summary, the working process of the voltage control energy supply circuit includes but is not limited to the following two logics:

(A) The matching logic of the voltage of the voltage output terminal V0 and the voltage of the two ends of the load, that is, the logic is based on non-dimming, and its action path is to first sample the voltage signal of the negative terminal V1 And complete the corresponding trimming and other processing to obtain a positive correlated and amplified mixed signal. It is understood from the above that when the voltage of the negative terminal V1 becomes larger, it means that the voltage across the load becomes smaller. If you do not adjust it at this time. , then the power consumption generated by multiplying the voltage of the negative terminal V1 by the current will be dissipated by the current regulation module, causing the temperature of the current regulation module to rise or even burn out; at this time, the feedback circuit unit The mixed signal and the first sampling signal from the voltage output terminal V0 are superimposed and fed into the output voltage adjustment feedback port FB, and the voltage control module can be used to reduce the voltage of the voltage output terminal V0, so that The voltage of the negative terminal V1 will also be correspondingly reduced to a preset value, otherwise, the voltage of the voltage output terminal V0 is increased to increase the voltage of the negative terminal V1, so that the current adjustment module works normally without Enter the non-constant current state, which can dynamically and continuously keep the current regulation module in the best working state, and also ensure the stability and good working efficiency of the entire voltage control function circuit;

(B) The logic of dynamically adjusting the voltage of the voltage output terminal V0 during the dimming process, that is, the dimming state is added on the basis of non-dimming. Although only the dimming state is added, the entire voltage control power supply The complexity of the circuit has increased a lot. It can be divided into two states to illustrate. The first is the dimming state, the second is the dimming state, and the dimming is the extreme case of dimming (that is, the dimming depth is 0 %), then the effect of this modulating state on the entire voltage control energy supply circuit is also extreme. In the dimming state, since the voltage waveform of the negative terminal V1 will superimpose a high-frequency ripple, the high-frequency ripple can be regarded as a high-frequency square wave superimposed with a low-frequency ripple after sampling and trimming. When the load current after dimming/dimming brightness is getting lower and lower, the amplitude of this waveform will increase accordingly. After sampling and trimming processing, the signal will rise as the load current decreases after dimming. , eventually the voltage of the voltage output terminal V0 will decrease as the load current becomes smaller after dimming, which has obvious adverse effects on the dimming effect. The second sampled signal of V1 is subjected to signal processing to obtain a mixed signal in which the frequency component (ie the vibration amplitude of the frequency signal) and the load current after dimming are non-linearly negatively correlated, so as to offset part of the influence of the rising trend; The smaller the load current after dimming, the more frequency components of the mixed signal will be extracted by the low level, which will remain unchanged or even show a downward trend (this adjustment can be achieved by setting the appropriate attenuation parameters here) , and finally, the voltage of the voltage output terminal V0 will also remain unchanged or show an upward trend, which fully guarantees the dimming effect. In the dimming state, since the load current is zero after dimming at this time, the frequency components extracted from the mixed signal are also the most. To ensure that the frequency components extracted from the mixed signal can be arbitrarily set, it is necessary to Add a corresponding circuit to make a logical judgment, so as to ensure that the signal given to the feedback circuit unit is lower than the threshold value in the modulating state, that is, the feedback circuit unit only receives the voltage from the voltage output terminal V0 at this time. The first sampling signal also makes the voltage control module output the highest voltage and the no-load voltage. In addition, if the current is increased from 0 after dimming, the logic processing process is reversed from the above description, and details are not repeated here.

Preferably, the signal sampling processing feedback dynamic adjustment module is further configured to trigger sending an alarm signal to the logic judgment unit when the second sampling signal or the mixed signal is found to be abnormal, so that the logic judgment unit is receiving When the alarm signal is reached, the magnitude of the current flowing through the load is adjusted to zero, so as to achieve the purpose of protecting the load by turning off the current. As shown in Figures 1 and 2, the aforementioned abnormality detection and alarm triggering actions can be performed by the signal processing module. To achieve the purpose of abnormal load protection.

To sum up, using the self-adaptive dimming voltage control energy supply circuit provided by this embodiment has the following technical effects:

(1) This embodiment provides a load driving scheme for feedback control of the output voltage based on the dimming signal and the sampling signal at both ends of the load, that is, it includes a voltage control module, a load, a current regulation module and a signal sampling processing feedback dynamic regulation module , wherein the voltage control module has an output voltage adjustment feedback port, and the signal sampling processing feedback dynamic adjustment module is used to signal the second sampling signal from the negative terminal of the load according to the dimming signal from the current adjustment module process to obtain a mixed signal whose frequency component is nonlinearly negatively correlated with the magnitude of the load current after dimming, and superimpose the mixed signal with the first sampling signal from the positive terminal of the load and feed it into the output voltage adjustment feedback port, so that The voltage control module dynamically adjusts the output voltage according to the input signal, so that in the entire dimming process, the difference between the output voltage of the voltage control module and the voltage at both ends of the load is always in a constant state preset by the circuit, and then It can realize that the output voltage of the pre-stage circuit and the output current of the post-stage circuit are stable without fluctuation, and at the same time, the post-stage circuit is always in a high-efficiency working state, which can effectively improve the performance of dimming, and is convenient for practical application and promotion;

(2) It can achieve the purpose of precise dimming, which can be compatible with a wider dimming frequency range, and can achieve ultra-low depth brightness, which can reach the industry's highest depth of less than 1/1,000. The dimming experience has been greatly improved;

(3) It can have a wider power application range, that is, compared with the solution of using DC to DC, the range of output power can be increased by 2-3 times without increasing the cost;

(4) It can have a smaller volume, that is, because the post-stage circuit adopts non-inductive technology, it has obvious advantages in volume. Compared with the same solution on the market, the volume can be reduced by more than 20%;

(5) It can have excellent EMC characteristics, that is, because the post-stage circuit adopts non-inductive technology, when only a single-stage power supply structure is used to meet PFC and THD, the EMC performance is excellent, regardless of internal interference or external radiation interference. , are significantly better than the solutions on the market.

Embodiment 2

As shown in FIG. 3 , on the basis of the technical solution of the first embodiment, this embodiment further provides a voltage-controlled energy supply circuit in which the switching power supply adopts an isolated flyback power supply topology, wherein the inductive element circuit The unit includes a flyback isolation transformer, and the output voltage can be filtered by a crystal diode and a capacitor; the input voltage VIN is various DC voltages; the switch control circuit unit adopts a circuit structure based on a controller and various switch tubes K1 . The aforementioned voltage-controlled energy supply circuit can be suitable for low-power driving, covering various types of LED driving power sources.

The technical effect of this embodiment can be derived by referring to the technical effect of the foregoing Embodiment 1, which will not be repeated here.

Embodiment 3

As shown in FIG. 4 , on the basis of the technical solution of Embodiment 1, this embodiment further provides a voltage-controlled energy supply circuit in which a switching power supply adopts a boost power supply topology, wherein the inductive element circuit unit includes a power supply circuit. Inductance, and the output voltage can also be filtered through crystal diodes and capacitors; the input voltage VIN is various DC voltages; the switch control circuit unit adopts a circuit structure based on a controller and various switch tubes K2. The aforementioned voltage-controlled energy supply circuit may be suitable for high-power driving, such as various outdoor lamps.

The technical effect of this embodiment can be derived by referring to the technical effect of the foregoing Embodiment 1, which will not be repeated here.

Embodiment 4

As shown in FIG. 5 , on the basis of the technical solution of the first embodiment, this embodiment further provides a voltage-controlled energy supply circuit in which the switching power supply adopts a step-down power supply topology, wherein the inductive element circuit unit includes a power supply circuit. Inductance, and the output voltage can also be filtered through crystal diodes and capacitors; the input voltage VIN is various DC voltages; the switch control circuit unit adopts a circuit structure based on a controller and various switch tubes K3. The aforementioned voltage-controlled energy supply circuit may be suitable for low-power driving.

The technical effect of this embodiment can be derived by referring to the technical effect of the foregoing Embodiment 1, which will not be repeated here.

Embodiment 5

As shown in FIG. 6 , based on the technical solution of the first embodiment, this embodiment also provides a voltage-controlled energy supply circuit that can meet other requirements such as power supply, safety regulations, and feedback detection, that is, when the inductive element When the circuit unit includes a transformer, the voltage control energy supply circuit further includes at least one auxiliary winding module; the auxiliary winding module includes a crystal diode, an electrolytic capacitor and an auxiliary winding, wherein the auxiliary winding and the transformer are connected. The main winding is in the same magnetic circuit, the anode of the crystal diode is connected to one end of the auxiliary winding, the cathode of the crystal diode is connected to the anode of the electrolytic capacitor, the cathode of the electrolytic capacitor is grounded, and the anode of the electrolytic capacitor is connected to the ground. As the power supply output terminal of the auxiliary winding module; the third signal sampling terminal of the signal sampling processing feedback dynamic adjustment module is connected to the power supply output terminal of an auxiliary winding module in the at least one auxiliary winding module; the signal sampling processing feedback The dynamic adjustment module is further configured to superimpose the third sampling signal from the power supply output end of the certain auxiliary winding module, the mixed signal and the first sampling signal into the output voltage adjustment feedback port FB, so that In the process of dynamically adjusting the output voltage according to the input signal, the voltage control module makes the switch control circuit unit enter the following intermittent power supply mode when it is found that the dimming depth is lower than the preset depth threshold: The voltage value of the third sampling signal is lower than the preset voltage threshold and is in a downward trend, then the energy supply is increased by shortening the interval between two adjacent energy supply pulses, and if the voltage value of the third sampling signal is rising trend and is close to the preset voltage threshold, the energy supply is reduced by extending the interval between two adjacent energy supply pulses, so that each auxiliary winding module can continuously and stably supply external energy with the cooperation of the corresponding electrolytic capacitors (that is, It will not appear that the energy output interval becomes larger, and the output ripple becomes larger and affects the use).

As shown in FIG. 6 , the at least one auxiliary winding module is denoted by HA, HB, HC, and HN, etc., in order to meet other requirements such as power supply, safety regulation and feedback detection, etc., wherein, the certain auxiliary winding module is denoted by HA , so as to serve as the feedback detection winding to feed back the load size, voltage level and power failure of the main winding, so that the signal sampling processing feedback dynamic adjustment module can combine the output voltage, load condition and dimming signal to realize the The extreme application of the continuous power supply of each auxiliary winding when the main winding output is light load or no load. This extreme application has obvious cost and technical advantages in dimming applications. For example, when the dimming depth is less than 10% (which can be used as the preset depth threshold) or dimmed, the output of the main winding is light. load or no-load (that is, when the dimming depth is less than 10% or the dimming is off, the signal processing circuit unit will have almost no mixed signal input to the feedback circuit unit, and at this time, the output voltage of the voltage control module will be close to / is the highest voltage state, but due to the small current flowing through the load, the output power of the main winding will be very low), and the auxiliary winding modules HA, HB and HC also provide different circuits. The required energy or detection signal; under normal circumstances, the voltage and current output by the auxiliary winding module will become too small to meet the normal demand, which is also a pain point in the market. Their approach is to directly add an independent The AC to DC power supply can meet the continuous power supply of the control logic circuit, which increases a lot in cost.

In this embodiment, it is considered that the energy supply and output demand of the auxiliary winding module is constant and continuous. Therefore, during the energy supply and discharge process of the corresponding electrolytic capacitor, the positive voltage of the electrolytic capacitor (that is, the third sampling The voltage value of the signal) becomes lower, so after the feedback through the feedback circuit unit, the switch control circuit unit can enter the intermittent power supply mode when it is found that the dimming depth is lower than the preset depth threshold value, To make the increased energy output from the auxiliary winding (that is, when the power supply increases, due to the strict volt-turn ratio principle, although the voltage control module will be difficult to have energy output because the output voltage exceeds the preset value, However, the auxiliary winding module will output increased energy because the output voltage is lower than the preset voltage threshold), and then can charge the electrolytic capacitor, suppress the drop of the positive voltage, and keep it within the preset voltage threshold. Level. Therefore, in this embodiment, there is no need to add a power supply circuit for converting AC to DC, which not only satisfies the normal power supply, but also greatly reduces the cost and simplifies the circuit design. In addition, intermittent energization by transmitting energizing pulses is a prior art approach.

The technical effects of this embodiment are based on the technical effects of the foregoing embodiment 1, and also have the following technical effects: (1) The auxiliary windings can still be maintained when the voltage control energy supply circuit is in deep dimming or even in standby. Good output capability enables other control logic circuits to keep running, which can greatly reduce costs and simplify circuit design for projects with integrated functions. Also more flexible.

Finally, it should be noted that the present invention is not limited to the above-mentioned optional embodiments, and anyone can obtain other various forms of products under the inspiration of the present invention. The above specific embodiments should not be construed as limiting the protection scope of the present invention, which should be defined in the claims, and the description can be used to interpret the claims.

Claims (10)

1. A self-adaptive dimming voltage-controlled energy supply circuit is characterized by comprising a voltage control module, a load, a current regulation module and a signal sampling processing feedback dynamic regulation module, wherein the voltage control module is provided with an output voltage regulation feedback port (FB), and the load is a light-emitting lamp;

the voltage control module is used for converting the input voltage into direct current voltage and outputting the direct current voltage;

the positive end of the load is connected with a voltage output end (V0) of the voltage control module, the negative end (V1) of the load is connected with one end of the current regulation module, and the other end of the current regulation module is grounded;

the current adjusting module is used for adjusting the current flowing through the load according to an external dimming signal so as to enable the voltage at two ends of the load to be matched with the voltage of the voltage output end (V0);

a first signal sampling end of the signal sampling processing feedback dynamic adjusting module is connected with the voltage output end (V0), a second signal sampling end of the signal sampling processing feedback dynamic adjusting module is connected with the negative electrode end (V1), a communication end of the signal sampling processing feedback dynamic adjusting module is connected with the current adjusting module, and a signal output end of the signal sampling processing feedback dynamic adjusting module is connected with the output voltage adjusting feedback port (FB);

the signal sampling processing feedback dynamic adjustment module is configured to perform signal processing on a second sampling signal from the negative terminal (V1) according to the dimming signal from the current adjustment module to obtain a mixed signal with a frequency component that is not linearly negatively correlated with the magnitude of the load current after dimming, and feed the mixed signal and a first sampling signal from the voltage output terminal (V0) into the output voltage adjustment feedback port (FB) in a superposed manner, so that the voltage control module dynamically adjusts the output voltage according to the fed signal, and the difference between the output voltage of the voltage control module and the voltages at the two ends is always in a constant state preset by a circuit in the whole dimming process.

2. The voltage-controlled power supply circuit according to claim 1, wherein the voltage control module employs a switching power supply including an inductive element circuit unit and a switching control circuit unit, wherein the inductive element circuit unit includes an inductor and/or a transformer, and the controlled terminal of the switching control circuit unit is used as the output voltage regulation feedback port (FB).

3. The voltage-controlled power supply circuit of claim 2, wherein when the inductive element circuit unit comprises a transformer, the voltage-controlled power supply circuit further comprises at least one auxiliary winding module;

the auxiliary winding module comprises a crystal diode, an electrolytic capacitor and an auxiliary winding, wherein the auxiliary winding and a main winding of the transformer are positioned in the same magnetic circuit, the anode of the crystal diode is connected with one end of the auxiliary winding, the cathode of the crystal diode is connected with the anode of the electrolytic capacitor, the cathode of the electrolytic capacitor is grounded, and the anode of the electrolytic capacitor is used as the power supply output end of the auxiliary winding module;

a third signal sampling end of the signal sampling processing feedback dynamic adjusting module is connected with a power supply output end of one auxiliary winding module in the at least one auxiliary winding module;

the signal sampling processing feedback dynamic adjustment module is further configured to superimpose and feed a third sampling signal from the power supply output end of the certain auxiliary winding module, the mixed signal and the first sampling signal into the output voltage adjustment feedback port (FB), so that when the voltage control module finds that the dimming depth is lower than the preset depth threshold in the process of dynamically adjusting the output voltage according to the fed-in signal, the voltage control module makes the switch control circuit unit enter the following intermittent power supply mode: if the voltage value of third sampled signal is less than and predetermines voltage threshold and be in the decline trend, then increases the energy supply through shortening the interval time of two adjacent energy supply pulses, and if the voltage value of third sampled signal is in the rising trend and is close predetermine voltage threshold, then reduce the energy supply through the interval time of two adjacent energy supply pulses of extension, and then make each auxiliary winding module continues to stabilize under the cooperation that corresponds electrolytic capacitor and externally supplies energy.

4. The voltage-controlled power supply circuit of claim 2, wherein the switching power supply adopts an isolated flyback power supply topology, a boost power supply topology or a buck power supply topology.

5. The voltage-controlled power supply circuit of claim 1, wherein the current regulating module comprises a current-stabilizing circuit unit and a logic determining unit, wherein the current-stabilizing circuit unit is integrated with the logic determining unit, the current-stabilizing circuit unit is configured to draw a current flowing through the load to ground, and the logic determining unit is configured to adjust the magnitude of the current flowing through the load according to an external dimming signal.

6. The voltage-controlled power supply circuit of claim 5, wherein the signal sampling processing feedback dynamic adjustment module is further configured to trigger sending of an alarm signal to the logic determination unit when the second sampling signal is found to be abnormal, so that the logic determination unit adjusts the current flowing through the load to zero when receiving the alarm signal, thereby achieving the purpose of protecting the load by turning off the current.

7. The voltage-controlled power supply circuit according to claim 1, wherein the signal sampling processing feedback dynamic adjustment module comprises a signal sampling trimming circuit unit, a signal processing circuit unit and a feedback circuit unit, wherein a signal input terminal of the signal sampling trimming circuit unit is connected to the negative terminal (V1) as a second signal sampling terminal of the signal sampling processing feedback dynamic adjustment module, a signal output terminal of the signal sampling trimming circuit unit is connected to a signal input terminal of the signal processing circuit unit, a signal output terminal of the signal processing circuit unit is connected to a second signal input terminal of the feedback circuit unit, a communication terminal of the signal processing circuit unit is connected to the current regulation module as a communication terminal of the signal sampling processing feedback dynamic adjustment module, and a first signal input terminal of the feedback circuit unit is connected to the first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module as a first signal sampling terminal of the signal sampling processing feedback dynamic adjustment module The voltage output end (V0) is connected, and the signal output end of the feedback circuit unit is used as the signal output end of the signal sampling processing feedback dynamic adjusting module and is connected with the output voltage adjusting feedback port (FB);

the signal sampling trimming circuit unit is used for trimming a second sampling signal from the negative electrode end (V1) and sending the trimmed signal obtained by processing to the signal processing circuit unit, wherein the trimming processing comprises filtering processing, voltage division and voltage limitation processing and integration processing which are sequentially carried out;

the signal processing circuit unit is used for performing signal processing on the trimmed signal according to the dimming signal from the current adjusting module to obtain a mixed signal of which the frequency component and the load current after dimming are in nonlinear negative correlation, and sending the mixed signal to the feedback circuit unit;

the feedback circuit unit is used for feeding the mixed signal and a first sampling signal from the voltage output end (V0) into the output voltage regulation feedback port (FB) in a superposition mode.

8. The voltage controlled power supply circuit according to claim 7, wherein the trimmed signal is signal-processed according to the dimming signal from the current adjusting module to obtain a mixed signal with a frequency component having a non-linear negative correlation with the magnitude of the load current after dimming, comprising:

and according to the dimming signal from the current adjusting module, carrying out attenuation processing on part of frequency components in the trimmed signal, wherein the attenuation processing is in nonlinear negative correlation with the magnitude of the load current after dimming, so as to obtain a mixed signal, the frequency components of which are in nonlinear negative correlation with the magnitude of the load current after dimming, and carrying out complete attenuation processing on all frequency components in the trimmed signal when the magnitude of the load current after dimming is in a dimming state, so that no signal is output to the feedback circuit unit.

9. The voltage controlled power supply circuit of claim 7, wherein feeding said mixed signal into said feedback circuit unit comprises:

and after the mixed signal is subjected to at least one-time integration processing, the mixed signal is amplified and sent to the feedback circuit unit.

10. The voltage-controlled energy supply circuit according to claim 7, wherein the signal sampling mode of the signal sampling trimming circuit unit is a direct sampling mode or an indirect sampling mode, wherein the direct sampling mode includes a resistance voltage-dividing shunt sampling mode, a triode shunt sampling mode, an operational amplifier lossless sampling mode, an optical coupling isolation sampling mode and/or a digital sampling mode based on a microprocessor MCU chip, and the indirect sampling mode is a sampling mode for boosting voltage by a voltage superposition processing technology.

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