Power detection device

Abstract

The invention provides a power detection device comprising a constant voltage module used for providing a constant first voltage for a constant current module, and the first voltage is used for providing a power supply signal for the constant current module; the constant current module is respectively connected with the constant voltage module and the LED light source and is used for adjusting the driving current of the LED light source according to the pulse width modulation signal; the micro-control unit is connected with the constant current module and the LED light source and used for providing a pulse width modulation signal for the constant current module and determining first input power of the LED light source according to the collected first target voltage and the output current of the LED light source. The input power of the LED light source is detected through the micro-control unit, compared with a traditional power detection circuit, detection lines are not added, and the purposes of cost reduction and availability are achieved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent detection technology, and in particular to a power detection device. Background Art

[0002] With the improvement of living standards, Light-Emitting Diode (LED) lighting is used in more and more scenarios. In the application of smart lighting, there is an application demand to drive the ability to report the working power to terminals such as servers or mobile phones in order to count the energy consumption of LED lamps and determine the working status of LED lamps.

[0003] The power detection circuit for intelligent lighting in the prior art is relatively complex and difficult to implement. Summary of the invention

[0004] The power detection device provided by the present invention is used to solve the problem in the prior art that the power detection circuit for intelligent lighting is relatively complex and difficult to implement.

[0005] The present invention provides a power detection device, comprising:

[0006] A constant current module, connected to the LED light source, and used to adjust the driving current of the LED light source according to the pulse width modulation signal;

[0007] A constant voltage module, connected to the constant current module, and used to provide a constant first voltage for the constant current module, wherein the first voltage is used to provide a power supply signal for the constant current module;

[0008] A microcontrol unit is respectively connected to the constant current module and the LED light source, and is used to provide the pulse width modulation signal for the constant current module, and obtain the first input power of the LED light source according to the collected output current of the LED light source and the first target voltage, wherein the output current of the LED light source is obtained according to the driving current, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, and the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage.

[0009] According to a power detection device provided by the present invention, the micro control unit is also used for:

[0010] acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of the pulse width modulation signal; and

[0011] The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

[0012] According to a power detection device provided by the present invention, the micro control unit is also used for:

[0013] The driving efficiency corresponding to the duty cycle of the pulse width modulation signal is determined according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

[0014] According to a power detection device provided by the present invention, the LED light source includes one or more groups of light source modules;

[0015] In the case where the LED light source includes a plurality of light source modules, the micro control unit is further used for:

[0016] A corresponding pulse width modulation signal is provided for each group of light source modules, and a second input power of the LED light source is obtained according to a second target voltage corresponding to each group of light source modules and a second output current corresponding to each group of light source modules. The second target voltage includes a third voltage and a voltage difference between the positive and negative electrodes of each group of light source modules. The third voltage is obtained by dividing the first voltage by a voltage-dividing resistor connected to each group of light source modules.

[0017] According to a power detection device provided by the present invention, when the LED light source includes multiple groups of light source modules, the micro control unit is further used for:

[0018] According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages;

[0019] The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

[0020] According to a power detection device provided by the present invention, the constant current module is composed of a Buck circuit and / or a Boost circuit;

[0021] The constant voltage module includes a linear voltage regulator circuit, a Zener voltage regulator circuit and a switching voltage regulator circuit, the power supply signal of the constant voltage module is provided by a power supply module, and the constant voltage module is connected to the power supply module;

[0022] The micro control unit adopts a single chip microcomputer or a microprocessor.

[0023] The present invention also provides a power detection method, comprising:

[0024] Providing a pulse width modulation signal to a constant current module, so that the constant current module adjusts the driving current of the LED light source according to the pulse width modulation signal, and the constant current module is connected to the LED light source;

[0025] The first input power of the LED light source is obtained according to the collected output current of the LED light source and the first target voltage, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage, the first voltage is provided to the constant current module by a constant voltage module, the constant voltage module is connected to the constant current module, and the first voltage is used to provide a power signal for the constant current module.

[0026] According to the power detection method provided by the present invention, the method further includes:

[0027] acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of a pulse width modulation signal; and

[0028] The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

[0029] According to the power detection method provided by the present invention, the method further includes:

[0030] The driving efficiency corresponding to the duty cycle of the pulse width modulation signal is determined according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

[0031] According to the power detection method provided by the present invention, the method further includes:

[0032] Providing a corresponding pulse width modulation signal for each group of light source modules in the LED light source, wherein the LED light source includes one or more groups of light source modules;

[0033] The second input power of the LED light source is obtained based on the collected second target voltage corresponding to each group of light source modules and the second output current corresponding to each group of light source modules, the second target voltage includes a third voltage and a voltage difference between the positive and negative poles of each group of light source modules, and the third voltage is obtained by dividing the first voltage through a voltage-dividing resistor connected to each group of light source modules.

[0034] According to the power detection method provided by the present invention, when the LED light source includes multiple groups of light source modules, the method further includes:

[0035] According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages;

[0036] The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

[0037] The power detection device provided by the present invention adds a microcontroller unit, a constant current module and a constant voltage module to the power detection device of the LED light source, and uses the microcontroller unit to detect the output current and the first target current of the LED light source. The detection device has a simple circuit and can detect the input power of the LED light source without the need for additional configuration of the detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is one of the structural schematic diagrams of the power detection device provided by the present invention;

[0040] Figure 2 This is the second structural schematic diagram of the power detection device provided by the present invention;

[0041] Figure 3It is a flow chart of the power detection method provided by the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Figure 1 FIG. 1 is one of the structural schematic diagrams of the power detection device provided by the present invention, such as Figure 1 As shown, including:

[0044] A constant current module, connected to the LED light source, and used to adjust the driving current of the LED light source according to the pulse width modulation signal;

[0045] A constant voltage module, connected to the constant current module, and used to provide a constant first voltage for the constant current module, wherein the first voltage is used to provide a power supply signal for the constant current module;

[0046] A microcontrol unit is respectively connected to the constant current module and the LED light source, and is used to provide the pulse width modulation signal for the constant current module, and obtain the first input power of the LED light source according to the collected output current of the LED light source and the first target voltage, wherein the output current of the LED light source is obtained according to the driving current, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, and the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage.

[0047] In some embodiments, the power detection device may specifically include a constant current drive circuit and an LED light source, and the constant current drive circuit may specifically consist of a constant voltage module, a constant current module and a microcontroller unit (MCU). The constant current module in the constant current drive circuit can adjust the drive current of the LED light source (or LED lamp) through a pulse width modulation (PWM) signal provided by the MCU, and the drive current determines the output current of the LED light source. The MCU also has other functions in intelligent lighting, and the present invention only describes the power detection part, and does not elaborate on the others.

[0048] The constant voltage module can be specifically used to output a constant voltage, that is, a first voltage. The first voltage can be specifically used to provide a working power signal for a constant current module connected to the constant voltage module, and can also be used for the MCU to determine the voltage difference between the positive and negative poles of the detected LED.

[0049] MCU detects three signals, the positive voltage of the LED light source output by the constant current module, the negative voltage of the LED light source and the lamp head detection signal of the LED light source. The output voltage Vled of the constant current module is the difference between the positive voltage V+ of the LED light source and the negative voltage V- of the LED light source, Vled = (V+) - (V-), Vled is the voltage difference between the positive and negative electrodes of the LED light source.

[0050] Specifically, the constant voltage module generates a constant first voltage, which is provided to the constant current module, and the first voltage is sampled by the constant current module. After sampling by the constant current module, the MCU can calculate the actual output voltage of the constant voltage module. Since the constant voltage module and the constant current module are in series, the actual output voltage of the constant voltage module is actually connected to the positive pole of the LED light source. The MCU can collect the positive pole voltage of the LED light source by detecting the actual output voltage of the constant voltage module. The constant current module is connected to the negative pole of the LED light source. The MCU can collect the negative pole voltage of the LED light source by detecting the output voltage of the constant current module.

[0051] The lamp holder detection signal is a voltage value obtained by dividing the first power supply according to the voltage dividing resistor connected to the LED light source, that is, the second voltage. LED light sources with different output currents correspond to a different and fixed voltage dividing value. The second voltage can be obtained by sampling the voltage dividing value of the voltage dividing resistor connected to the LED light source through the MCU's digital-to-analog converter ADC.

[0052] The MCU can obtain the first target voltage based on the collected second voltage and the voltage difference between the positive and negative electrodes of the LED light source, and calculate the input power of the LED light source, that is, the first input power, based on the first target voltage and the output current of the LED light source.

[0053] The power detection device provided by the present invention adds a microcontroller unit, a constant current module and a constant voltage module to the power detection device of the LED light source, and uses the microcontroller unit to detect the output current and the first target current of the LED light source. The detection device has a simple circuit and can detect the input power of the LED light source without the need for additional configuration of the detection circuit.

[0054] Furthermore, in one embodiment, the micro control unit may also be specifically used for:

[0055] acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of the pulse width modulation signal; and

[0056] The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

[0057] In some embodiments, the MCU internally stores a mapping table (i.e., a first mapping table) of the output currents (i.e., the first output currents) of the LED light sources corresponding to different second voltages. The MCU uses the internally stored first mapping table to obtain the first output circuit matching the second voltage by looking up the table. The first output current Io1 can be adjusted by adjusting the driving current, and the driving current can be specifically adjusted by adjusting the duty cycle of the PWM signal by the MCU.

[0058] The MCU calculates the output power Po1 of the LED light source by collecting the voltage difference between the positive and negative electrodes of the LED light source and the first output current of the LED light source, where Po1=Io1*Vled.

[0059] The output power Po1 is calculated when the duty cycle of the PWM signal is 100%. The calculation method of the output power Po1 of the LED corresponding to the PWM signal under different duty cycles (PWM signal high level time ton / PWM signal period T) is updated to: Po1=Io1*Vled*D, wherein D is the first duty cycle corresponding to the first output current. Under different first duty cycles, the corresponding first output current is different. In actual situation, the first output current is equal to Io1*D, and the size of the first output current is directly proportional to the first duty cycle.

[0060] In the formula Po1=Io1*Vled*D, Po1 is actually the output power of driving the LED light source. What we actually need to know is the input power of the LED light source. The MCU uses the driving efficiency corresponding to the first duty cycle (i.e., the first driving efficiency) to calculate the input power Pi1 of the LED light source. Pi1=Po1 / η1, where η1 is the driving efficiency, i.e., the first driving efficiency.

[0061] Since the efficiency of the driver is not much different after the device selection, D takes n test points from 1% to 100% (usually 10 points, i.e. one point for every 10% duty cycle), and each point takes the efficiency of multiple test drivers at the corresponding duty cycle, and then takes the average. In this way, the first drive efficiency corresponding to n duty cycle points is obtained, and these values ​​are burned into the MCU. According to the current PWM duty cycle D, the MCU divides the output power Po1 of the LED light source after sampling and calculation by the corresponding first drive efficiency η1 to obtain the first input power of the LED light source.

[0062] In the power detection device provided by the present invention, the MCU can obtain the output current of the LED light source corresponding to the second power supply through the first mapping table stored internally, and realize input power detection of the LED light source based on the output current, the duty cycle of the PWM signal corresponding to the output current, the driving efficiency corresponding to the duty cycle and the voltage difference between the positive and negative electrodes of the LED light source.

[0063] Further, in one embodiment, the LED light source includes one or more groups of light source modules;

[0064] In the case where the LED light source includes a plurality of light source modules, the micro control unit is further used for:

[0065] A corresponding pulse width modulation signal is provided for each group of light source modules, and a second input power of the LED light source is obtained according to a second target voltage corresponding to each group of light source modules and a second output current corresponding to each group of light source modules. The second target voltage includes a third voltage and a voltage difference between the positive and negative electrodes of each group of light source modules. The third voltage is obtained by dividing the first voltage by a voltage-dividing resistor connected to each group of light source modules.

[0066] In some embodiments, the LED light source in the present invention may be composed of one or more groups of light source modules, wherein each group of light source modules may use light source modules with the same color temperature or light source modules with different color temperatures.

[0067] In some embodiments, when the LED light source includes multiple groups of light source modules, the MCU can also be specifically used to provide a corresponding PWM signal for each group of light source modules, and determine the second input power of the LED light source based on the collected second target voltage corresponding to each group of light source modules.

[0068] In some embodiments, the second target voltage includes a third voltage and a voltage difference between positive and negative electrodes of each light source module group. The third voltage can be obtained by dividing the first voltage using a voltage-dividing resistor connected to each light source module group.

[0069] For example, Figure 2This is the second structural diagram of the power detection device provided by the present invention, such as Figure 2 As shown, this is the application of the present invention in the intelligent constant current drive of 2-way PWM dimming with constant current output, which is composed of three parts: constant voltage module, MCU and constant current module. The constant current module is an independent 2-way step-down Buck circuit, which can adjust the output current through the PWM signal of the MCU.

[0070] The MCU can output two PWM signals, assuming they are PWMW signal and PWMC signal, which are respectively connected to the dimming PWM pins of the two dimming Buck circuits. The MCU has other functions in this intelligent drive. In this example, only the function of calculating the input power of the present invention is described, and other functions are not described.

[0071] The LED light source is composed of two groups of light source modules with different color temperatures, which are respectively connected to the two outputs of the constant current module.

[0072] One light source module is a LED string with a color temperature of 2700K, and the other light source module is a LED string with a color temperature of 6500K. Different color temperatures and brightness can be obtained by different currents. The light source module in the LED light source is connected to the constant current module through 5 wires, LEDW+, LEDW-, LEDC+, LEDC-, and Check ID. The LEDW+ and LEDC+ of these 5 wires are common anodes in the driver, that is, they are short-circuited in the constant current module, and are directly connected to the output end of the constant voltage module in the constant current module.

[0073] The MCU can obtain the positive voltage of the two light source modules by measuring the voltage of LEDW+ or LEDC+, and the negative voltage of the two light source modules by measuring the voltage of LEDW- and LEDC-. The voltage difference between the positive and negative electrodes of each group of light source modules can be obtained by subtracting the corresponding positive and negative voltages of each group of light source modules.

[0074] There are 2 groups of LED lamp beads with different color temperatures inside the LED light source. Each of the two LED lamp beads has 2 wires connected to the corresponding output line of the constant current module. There is also a Check ID line and a resistor R_LED inside the LED light source. The resistance value of R_LED corresponding to LED light sources of different specifications is different. Each resistance value corresponds to the working current (i.e., output current) of an LED light source. One side of R_LED in the LED light source is connected to the LED+ terminal, and the other side is connected to the Check ID line. After the LED light source and the constant current module are connected, R_LED and the voltage divider resistor R1 are connected to form a voltage divider and provide it to PIN9 of the MCU. Since the resistance value of R_LED varies with the LED light source, the voltage divider on PIN9 is different. After sampling, the ADC in the MCU can obtain different voltage divider values, i.e., the third voltage.

[0075] The MCU calculates the second input power of the LED light source by using the collected second target voltage corresponding to each group of light source modules and the second output current of each group of light source modules.

[0076] Furthermore, in one embodiment, when the LED light source includes a plurality of light source modules, the micro control unit is further configured to:

[0077] According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages;

[0078] The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

[0079] In some embodiments, the MCU also stores a mapping table of the second output currents corresponding to different third voltages of each group of light source modules, namely a third mapping table. The MCU can obtain the second output current corresponding to the third voltage of each group of light source modules by looking up the third mapping table.

[0080] The MCU calculates the second input power of the LED light source based on the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference of each group of light source modules and the second driving efficiency corresponding to the second duty cycle.

[0081] Likewise Figure 2 Taking the power detection device shown as an example, the constant voltage module is used to convert the grid voltage to output a fixed first voltage. This constant voltage module is not limited to the architecture. In this example, it is a flyback isolation architecture. It can also be other power architectures or non-isolated architectures, as long as it can generate a fixed voltage. In this example, the output 50V is marked for convenience of explanation. This voltage can be any suitable voltage according to the actual situation.

[0082] The constant current module in this example is a Buck constant current architecture, but it can also be other architectures, as long as it has a PWM dimming function. This example has two constant currents, corresponding to different color temperatures, and can also be single or multiple. For each additional channel, an additional voltage detection channel is required.

[0083] R2, R4 are connected to 50V LEDW+, LEDC+, LEDW+, LEDC+ are short-circuited in the driver to the same potential. R2, R4 divide the voltage to get an analog voltage which is sent to PIN10 of MCU. MCU samples the analog signal with ADC and multiplies it by the voltage divider ratio of R2, R4 to get the voltage V_LED+ of the positive electrode of the LED light source.

[0084] R13 and R14 are connected to the LEDW- terminal of the 2700K warm color temperature constant current driver. After R13 and R14 divide the voltage, an analog voltage is obtained and transmitted to PIN8 of the MCU. The MCU performs ADC sampling on this analog signal and multiplies it by the R13 and R14 voltage divider ratio to obtain the negative voltage V_LEDW- of LEDW.

[0085] R16, R18 are connected to the LEDC- end of the 6000K cold color temperature constant current driver. After R16, R18 divide the voltage, an analog voltage is obtained and transmitted to PIN7 of the MCU. The MCU performs ADC sampling on this analog signal and multiplies it by the R16, R18 voltage division ratio to obtain the voltage V_LEDC- at the cathode of LEDC.

[0086] After sampling the above three voltages, three voltage quantities V_LED+, V_LEDW- and V_LEDC- are obtained. Then the voltage difference between the positive and negative electrodes of the LED of the warm color temperature light source module is V_w=(V_LED+)-(V_LEDW-), and the voltage difference between the positive and negative electrodes of the LED of the cold color temperature light source module is V_c=(V_LED+)-(V_LEDC-).

[0087] The MCU queries the third mapping table to obtain the second output current corresponding to the third voltage, and determines the second input power of the LED light source by using the second duty cycle of the PWM signal corresponding to the second output current of each light source module, the second output current, the voltage difference between the positive and negative electrodes of each light source module, and the second driving efficiency corresponding to the second duty cycle. The MCU can determine what kind of LED light source is connected by sampling the third voltage, and also know the output current Io_max corresponding to this LED light source. This current is the maximum output current corresponding to the PWM signal with a duty cycle of 100%, and the output currents of other duty cycles also need to be obtained.

[0088] The output power of the light source module of the warm color path is P_wo=V_w*Io_max*D_w, and the output power of the light source module of the cold color path is P_co=V_c*Io_max*D_c, wherein D_w is the second duty cycle of the PWMW signal of the light source module of the warm color path, and D_c is the second duty cycle of the PWMC signal of the light source module of the cold color path.

[0089] From the above, we know the output power of the two paths, and the output power Po2 of the LED light source is the sum of the power of the two paths Po2 = P_wo + P_co.

[0090] Usually, the driving components are mass-produced according to specifications, with little overall error and little difference in overall driving efficiency. The overall input power can be calculated by pre-testing the efficiency of other drivers. The driving efficiency under different duty cycles is different, so it is necessary to test the efficiency under different duty cycles in advance and then store the data in the MCU. In actual calculation, the MCU finds the corresponding driving efficiency through the duty cycle of the PWM signal it outputs and then deduce the driving efficiency.

[0091] Specifically, the MCU can first select m drivers, and then divide the duty cycle from 0-100% into n parts. The larger the number n, the more data needs to be tested, and the more accurate the final result. Under different n PWM signal duty cycles, the efficiency of the m drivers is measured and the average value is taken. The n average values ​​are made into a data table corresponding to the duty cycle and stored in the MCU. The MCU reads the drive efficiency according to the corresponding actual duty cycle, that is, the second drive efficiency. The actual second input power of the LED light source is Pi2=Po / η2.

[0092] The power detection device provided by the present invention provides a multi-channel PWM signal to a constant current module through an MCU to adjust the driving current of a multi-channel light source module with different color temperatures in an LED light source in intelligent lighting. The driving current directly affects the output current of the multi-channel light source module connected to the constant current module, and calculates the input power of the multi-channel light source module based on the MCU. Compared with a traditional power detection circuit, no additional detection circuit is added, and the implementation is simple and the cost is low.

[0093] Further, in one embodiment, the constant current module is composed of a Buck circuit and / or a Boost circuit;

[0094] The constant voltage module includes a linear voltage regulator circuit, a Zener voltage regulator circuit and a switching voltage regulator circuit, the power supply signal of the constant voltage module is provided by a power supply module, and the constant voltage module is connected to the power supply module;

[0095] The micro control unit adopts a single chip microcomputer or a microprocessor.

[0096] In some embodiments, the constant current module may be specifically formed by a Buck circuit and / or a Boost circuit.

[0097] For example, Figure 2 The constant current module shown is composed of two Buck circuits, which may specifically include Buck chips (U3 and U4), ceramic capacitors (C1, C2, C5-C9), resistors (R1, R2, R4, R13-R18), inductors (L3 and L4) and diodes (D5 and D6).

[0098] In some embodiments, the constant voltage module may specifically adopt any one of a linear regulator circuit, a Zener regulator circuit and a switching regulator circuit, or may adopt a Figure 2 The flyback isolation circuit shown includes a rectifier bridge DB, a flyback chip U2, a ceramic capacitor C3, electrolytic capacitors (EC1 and EC3), resistors (R3, R5, R6, R10 and R12), diodes (D1 and D3), a transformer T1 and a switching element Q2 (e.g., a transistor).

[0099] In some embodiments, the MCU may specifically be a single-chip microcomputer or a microprocessor (eg, an ARM chip).

[0100] like Figure 2 As shown, the single-chip microcomputer CON1 is used as the MCU.

[0101] In some embodiments, the power detection device may further specifically include a power module, which is connected to the constant voltage module and can be specifically used to provide a power signal for the constant voltage module.

[0102] The power detection device provided by the present invention can select different constant voltage modules, constant current modules and MCU according to different requirements to realize input power detection of LED light sources, and has a simple structure and is easy to realize.

[0103] Furthermore, in one embodiment, the micro control unit is also used for:

[0104] The driving efficiency corresponding to the duty cycle of the pulse width modulation signal is determined according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

[0105] In some embodiments, the MCU can also be specifically used to determine the driving efficiency (including the first driving efficiency and the second driving efficiency) corresponding to the duty cycle of the PWM signal provided to the constant current module based on the driving efficiency corresponding to the PWM signals with different duty cycles stored internally.

[0106] The efficiency detection device provided by the present invention detects that the input power of the LED light source is different from the input power directly detected by the power meter. In actual comparison, it is found that the error can be controlled within 5%. In power detection applications with low requirements, it has the characteristics of simple circuits. It only needs to detect the positive and negative voltages of the LED light source, the Check ID voltage, the output current of the LED light source and the driving efficiency to realize the input power detection of the LED light source. The circuit is simple and easy to implement.

[0107] The power detection method provided by the present invention is described below. The power detection method described below is implemented on the basis of the power detection device described above.

[0108] Figure 3 It is a flow chart of the power detection method provided by the present invention, such as Figure 3 As shown, including:

[0109] Step 110, providing a pulse width modulation signal to a constant current module, so that the constant current module adjusts the driving current of the LED light source according to the pulse width modulation signal, and the constant current module is connected to the LED light source;

[0110] The first input power of the LED light source is obtained according to the collected output current of the LED light source and the first target voltage, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage, the first voltage is provided to the constant current module by a constant voltage module, the constant voltage module is connected to the constant current module, and the first voltage is used to provide a power signal for the constant current module.

[0111] The efficiency detection method provided by the present invention adds a microcontroller unit, a constant current module and a constant voltage module to the power detection device of the LED light source, and uses the microcontroller unit to detect the output current and the first target current of the LED light source. The detection device has a simple circuit and can detect the input power of the LED light source without the need for additional configuration of the detection circuit.

[0112] Furthermore, in one embodiment, the method further comprises:

[0113] acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of a pulse width modulation signal; and

[0114] The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

[0115] According to the efficiency detection method provided by the present invention, the MCU can obtain the output current of the LED light source corresponding to the second power supply through the first mapping table stored internally, and realize the input power detection of the LED light source based on the output current, the duty cycle of the PWM signal corresponding to the output current, the driving efficiency corresponding to the duty cycle and the voltage difference between the positive and negative electrodes of the LED light source.

[0116] Furthermore, in one embodiment, the method further comprises:

[0117] Providing a corresponding pulse width modulation signal for each group of light source modules in the LED light source, wherein the LED light source includes one or more groups of light source modules;

[0118] The second input power of the LED light source is obtained based on the collected second target voltage corresponding to each group of light source modules and the second output current corresponding to each group of light source modules, the second target voltage includes a third voltage and a voltage difference between the positive and negative poles of each group of light source modules, and the third voltage is obtained by dividing the first voltage through a voltage-dividing resistor connected to each group of light source modules.

[0119] Furthermore, in one embodiment, when the LED light source includes a plurality of light source modules, the method further includes:

[0120] According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages;

[0121] The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

[0122] The power detection method provided by the present invention provides a multi-channel PWM signal to a constant current module through an MCU to adjust the driving current of a multi-channel light source module with different color temperatures in an LED light source in intelligent lighting. The driving current directly affects the output current of the multi-channel light source module connected to the constant current module, and calculates the input power of the multi-channel light source module based on the MCU. Compared with a traditional power detection circuit, no additional detection circuit is added, and the implementation is simple and the cost is low.

[0123] Furthermore, in one embodiment, the method further comprises:

[0124] The driving efficiency corresponding to the duty cycle of the pulse width modulation signal is determined according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

[0125] The efficiency detection method provided by the present invention detects that there is a difference between the input power of the LED light source and the input power directly detected by the power meter. In actual comparison, it is found that the error can be controlled within 5%. In power detection applications with low requirements, the method has the characteristics of simple circuits. It only needs to detect the positive and negative voltages of the LED light source, the Check ID voltage, the output current of the LED light source and the driving efficiency to realize the input power detection of the LED light source. The circuit is simple and easy to implement.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power detection device, characterized in that: include: A constant current module, connected to the LED light source, and used to adjust the driving current of the LED light source according to the pulse width modulation signal; A constant voltage module, connected to the constant current module, and used to provide a constant first voltage for the constant current module, wherein the first voltage is used to provide a power supply signal for the constant current module; A microcontrol unit is respectively connected to the constant current module and the LED light source, and is used to provide the pulse width modulation signal for the constant current module, and obtain the first input power of the LED light source according to the collected output current of the LED light source and the first target voltage, wherein the output current of the LED light source is obtained according to the driving current, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, and the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage.

2. The power detection device according to claim 1, characterized in that: The micro control unit is also used for: acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of the pulse width modulation signal; and The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

3. The power detection device according to claim 2, characterized in that: The micro control unit is also used for: The driving efficiency corresponding to the duty cycle of the pulse width modulation signal is determined according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

4. The power detection device according to any one of claims 1 to 3, characterized in that: The LED light source includes one or more light source modules; In the case that the LED light source includes multiple groups of light source modules, the microcontroller unit is also used to: provide the corresponding pulse width modulation signal for each group of light source modules, and obtain the second input power of the LED light source according to the collected second target voltage corresponding to each group of light source modules and the second output current corresponding to each group of light source modules, the second target voltage includes a third voltage and the voltage difference between the positive and negative poles of each group of light source modules, and the third voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to each group of light source modules.

5. The power detection device according to claim 4, characterized in that: In the case where the LED light source includes a plurality of light source modules, the micro control unit is further used for: According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages; The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

6. The power detection device according to claim 5, characterized in that: The constant current module is composed of a Buck circuit and / or a Boost circuit; The constant voltage module includes a linear voltage regulator circuit, a Zener voltage regulator circuit and a switching voltage regulator circuit, the power supply signal of the constant voltage module is provided by a power supply module, and the constant voltage module is connected to the power supply module; The micro control unit adopts a single chip microcomputer or a microprocessor.

7. A power detection method, characterized in that: The power detection device according to any one of claims 1 to 6 comprises: Providing a pulse width modulation signal to a constant current module, so that the constant current module adjusts the driving current of the LED light source according to the pulse width modulation signal, and the constant current module is connected to the LED light source; The first input power of the LED light source is obtained according to the collected output current of the LED light source and the first target voltage, the first target voltage includes a second voltage and a voltage difference between the positive and negative electrodes of the LED light source, the second voltage is obtained after dividing the first voltage by a voltage-dividing resistor connected to the LED light source, the voltage difference between the positive and negative electrodes of the LED light source is obtained according to the first voltage, the first voltage is provided to the constant current module by a constant voltage module, the constant voltage module is connected to the constant current module, and the first voltage is used to provide a power signal for the constant current module.

8. The power detection method according to claim 7, characterized in that: The method further comprises: acquiring a first output current corresponding to the second voltage according to a first mapping table stored internally, wherein the first mapping table is used to store the first output current corresponding to the LED light source at different second voltages, wherein the first output current is adjusted by adjusting the driving current, and the driving current is adjusted by adjusting the duty cycle of a pulse width modulation signal; and The first input power is obtained according to a first duty cycle of a pulse width modulation signal corresponding to the first output current, the first output current, a voltage difference between positive and negative electrodes of the LED light source, and a first driving efficiency corresponding to the first duty cycle.

9. The power detection method according to claim 8, characterized in that: The method further includes: determining the driving efficiency corresponding to the duty cycle of the pulse width modulation signal according to a second mapping table stored internally, wherein the second mapping table is used to store driving efficiencies corresponding to different duty cycles.

10. The power detection method according to any one of claims 7 to 9, characterized in that: The method further comprises: Providing a corresponding pulse width modulation signal for each group of light source modules in the LED light source, wherein the LED light source includes one or more groups of light source modules; The second input power of the LED light source is obtained based on the collected second target voltage corresponding to each group of light source modules and the second output current corresponding to each group of light source modules, the second target voltage includes a third voltage and a voltage difference between the positive and negative poles of each group of light source modules, and the third voltage is obtained by dividing the first voltage through a voltage-dividing resistor connected to each group of light source modules.

11. The power detection method according to claim 10, characterized in that: In the case where the LED light source includes a plurality of light source modules, the method further includes: According to a third mapping table stored internally, obtaining a second output current corresponding to the third voltage of each group of light source modules, wherein the third mapping table stores second output currents corresponding to different third voltages; The second input power of the LED light source is determined according to the second duty cycle corresponding to the second output current of each group of light source modules, the second output current, the voltage difference between the positive and negative electrodes of each group of light source modules, and the second driving efficiency corresponding to the second duty cycle.

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