1113 results about "Voltage divider" patented technology

The invention discloses a DC voltage divider parameter anomaly detection method based on harmonic characteristics, and the method comprises the steps: deploying an isolation type voltage sensor at a bus of a DC power transmission system, carrying out the voltage sampling through combining with an ADC, carrying out the data buffering and preprocessing, extracting a fundamental wave component and a target harmonic component through the fast Fourier transform, and calculating the harmonic distortion rate. And constructing a low-voltage arm capacitance and harmonic distortion rate model based on a voltage divider secondary circuit equivalent circuit and an energy distribution principle, and calibrating the low-voltage arm capacitance and harmonic distortion rate model. And designing a multi-objective optimization scheduling algorithm based on energy storage capacity and capacitance characteristics, and realizing dynamic power distribution and harmonic suppression of the system. And after abnormal triggering, the system automatically loads a capacitance compensation coefficient, adaptively adjusts algorithm parameters in combination with a measurement loop PI control link, reduces a harmonic amplification effect, and ensures that a measurement error is within an acceptable range. Harmonic monitoring precision and capacitance compensation optimization capability of the direct-current power transmission system are effectively improved, and stable operation of the system is guaranteed.

The invention relates to the technical field of voltage acquisition, in particular to a battery string voltage acquisition system with a calibration system and a voltage acquisition method. Which comprises a multi-path voltage input end, a voltage signal adjusting end, a voltage follower, an analog-to-digital converter, a main control center and a communication circuit, and is characterized in that the voltage signal adjusting end comprises a dynamic voltage division network, consists of a digital potentiometer and a high-voltage operational amplifier, and dynamically adjusts the voltage division ratio to suppress common-mode voltage; the main control center is integrated with a multi-channel synchronous sampling calibration module and generates a global synchronous signal through the main MCU to control the ADC to perform synchronous acquisition; a temperature compensation module is arranged between the voltage follower and the ADC, and a digital temperature sensor is adopted to correct the gain drift of the operational amplifier in real time; the voltage division ratio of the dynamic voltage division network is dynamically adjusted according to the real-time common-mode voltage and a preset safety threshold value. According to the scheme, dynamic partial pressure adjustment, multi-channel self-calibration, nonlinear temperature compensation and a rapid protection mechanism can be integrated.

The invention relates to the technical field of medical instruments, in particular to a high-precision time interference non-invasive brain deep electrical stimulation method, equipment and system, and solves the problems that two stimulation electrodes are used for each pair of current in traditional time interference-based non-invasive brain deep electrical stimulation, so that the current distribution is relatively dispersed, and the stimulation focusing performance is relatively poor. According to the method, high-precision 4 * 1 electrode configuration is used, two electrodes for applying a stimulation current are changed into a 4 * 1 electrode form, the flowing path of the current is effectively limited, the current is more focused, and the focusing performance of the interference current is further improved. According to the device, high-precision current control is realized through the anti-phase output circuit, the 4 * 1 voltage division circuit, the constant current source module and the impedance detection module; the system supports forward and reverse electrode position optimization, a personalized real finite element head model simulation system based on MRI data is used for guiding practical application, the focusing performance of each pair of current in a target brain region is improved, and therefore the overall stimulation precision in the target brain region is improved.

A programmable driver circuit (54) and related method (600) for simultaneously controlling multiple tunable probabilistic bit generators are disclosed. The driver circuit comprises a plurality of programmable voltage generators (52; 30), a programming unit (35) and a non-volatile memory unit (34a-b). Input terminals of the plurality of programmable voltage generators are jointly connectible to a single voltage supply source. The programming unit is configured to generate a sequence of programming pulses for the different voltage generators. Each voltage generator comprises a single-stage or multi-stage voltage divider circuit (31) formed by a series of resistive elements (32-1; 32-2; 33). The non-volatile memory unit (34a-b) comprises at least the resistive element positioned first in the series of resistive elements as a programmable resistance and a program control transistor (34-1) connected in series between the programmable resistance and a fixed reference voltage. A control gate of the program control transistor is operatively coupled to the programming unit to receive the sequence of programming pulses for the programmable voltage generator when operated in a programming mode.

The power supply conversion circuit includes an isolation transformer, and the isolation transformer includes at least two primary coils and at least one secondary coil. Each primary coil is connected to a half-bridge circuit by using a first resonant network, and half-bridge circuits corresponding to the at least two primary coils are connected in series between two electrodes of a power supply. The half-bridge circuit is connected in parallel to a voltage divider, the voltage divider includes a first capacitor and a second capacitor that are connected in series, a first terminal of the first resonant network is connected to an intermediate node of the half-bridge circuit, and a second terminal of the first resonant network is connected to a connection point between the first capacitor and the second capacitor.

A device for ascertaining a property of a fluid, having: an electric conductor assembly which is designed to be at least partly brought into contact with the fluid and which is designed as a voltage divider with two elements, wherein the first element is a first conductor which, at least in a current-conducting state, has a resistance value that differs from that of the second element; a measuring bridge with two voltage dividers connected in parallel, one of said voltage dividers being formed by the electric conductor assembly; an actuation unit for applying an AC voltage to the measuring bridge; a voltage detection unit for detecting a bridge voltage; and an analysis unit which is configured to ascertain a thermal conductivity as the property of the fluid by analyzing the bridge voltage using the 3-omega method.

The invention belongs to the technical field of current source control, and particularly relates to a self-adaptive intelligent current source output control system, and the system works cooperatively through a plurality of modules: a load detection module monitors the load access state in real time, converts a current signal into a voltage signal Udetect, and outputs the voltage signal Udetect; the state stabilization filtering module receives the signal, filters high-frequency noise through an RC low-pass filtering unit, amplifies the signal through an in-phase proportion amplification unit, and is internally provided with a signal monitoring and judging unit to extract a load characteristic signal INPUTIDE in a stable working state; the feedback calculation module generates a feedback control parameter through preset threshold comparison and logical operation according to the INPUTIDE; the analog switch control module selects a resistance potential-divider network input channel according to the feedback control parameters, and outputs a current source regulation and control signal VC; and the adjustable current source module outputs a working current adaptive to the load according to the VC. The self-adaptive intelligent current source output control system is superior to a traditional system in dynamic adaptation, protection mechanism, multi-scene adaptation, precision and stability.

The invention discloses a virtual connection detection circuit, device and method, and relates to the technical field of circuits, the circuit comprises a comparator, a first resistor, a voltage divider and an indicator; the positive input end of the comparator is used for being connected with a moving point of the voltage divider, the first end of the voltage divider is used for being connected with power supply voltage, and the second end of the voltage divider is used for being grounded; the negative input end of the comparator is used for being connected with the first end of the first resistor, the second end of the first resistor is grounded, the negative input end of the comparator is further used for being connected with the first end of a wire to be detected, and the second end of the wire to be detected is used for being connected with input voltage; the output end of the comparator is used for being connected with an indicator, and the indicator is used for indicating a detection result. The circuit can detect the virtual connection phenomenon, thereby guaranteeing the normal connection of a lead, and reducing the error of a test result.

An electrically conductive circuit has a distal end coupled to a catalytic converter of a vehicle. A sensor such as a voltage divider is coupled to a proximal end of this conductive circuit. The voltage divider senses when a resistance associated with the conductive circuit is altered, indicative of catalytic converter tampering. An alarm signal can then be sent to the vehicle horn or otherwise beneficially outputted to warn of the tampering. The conductive circuit preferably includes a length of nichrome wire having a substantial resistance. Reliable electrical connection and tampering avoidance can be provided at the distal end of the nichrome wire by utilizing an electrically conductive washer at the distal tip, covering the nichrome wire with high temperature insulating tape, overlying the tape with a pipe clamp and encapsulating the washer, distal end of the nichrome wire, insulating tape and pipe clamp with a high temperature bonding adhesive.

The invention discloses an intelligent control method and system for calibration of a full-automatic sectional direct-current voltage divider, and relates to the technical field of intelligent control and decision making, and the method comprises the steps: automatically recognizing basic parameters of a calibrated voltage divider through a scanning test, detecting the sectional characteristics of the calibrated voltage divider, and building a characteristic model of the calibrated voltage divider; determining a calibration scheme according to the characteristic model, generating test point distribution, time sequence control parameters and a security policy, performing segmented calibration based on the calibration scheme, calculating error information of each test point, obtaining an independent compensation coefficient of each segment according to segmentation characteristics by combining temperature compensation, and performing compensation correction; and obtaining the corrected test point calibration result distribution to evaluate the health state of the calibrated voltage divider, and outputting a calibration conclusion including health state evaluation. Through the intelligent calibration process, the calibration efficiency and accuracy of the direct current voltage divider are remarkably improved, meanwhile, the operation risk is reduced, and reliable technical guarantee is provided for high-voltage direct current measurement.

The invention relates to a full-simulation non-multiplication and addition operation method and device for simulation in-memory calculation, and the method comprises the steps: training a target full model, and obtaining a corresponding weight and a batch normalization parameter, the batch normalization parameter comprising bias information and a zoom factor; based on the simulation in-memory calculation array and the simulation bias array, in combination with the weight and bias information, carrying out multiplication and addition operation and batch normalized bias calculation; generating a target reference voltage of the ReLU-ADC based on a global resistance ladder voltage divider or an analog bias array in combination with a scaling factor, and setting a DAC minimum output voltage thereof; and based on the target reference voltage and the minimum output voltage of the DAC, the ReLU-ADC performs full-simulation non-multiplication-addition operation on the bias multiplication-addition simulation calculation result. Therefore, the problems that in a traditional CIM architecture, a mode of completing non-multiplication and addition operation depending on a digital domain has significant bottlenecks in key performance indexes such as speed, power consumption and area, and the requirements of resource-limited scenes such as an intelligent sensor are difficult to meet are solved.

In the present invention, an abnormality detection unit comprises first voltage divider resistors connected between a first external terminal and a second external terminal, second voltage divider resistors connected between the second external terminal and a ground potential application end, first switches connected between the first external terminal and the second external terminal, second switches connected between the second external terminal and the ground potential application end, first comparators configured to compare the voltage between the first external terminal and the second external terminal with first reference voltages, and second comparators configured to compare the voltage between the second external terminal and the ground potential application end with second reference voltages.

The invention provides an efficient solar water heater, and belongs to the technical field of solar water heaters. Comprising a support, and a base is fixed to the support and used for stably supporting the whole device. The reflecting plate is connected with a heat preservation water tank, the heat preservation water tank is installed on the top of the base, the reflecting plate is installed around the base and can rotate around the base, a vacuum heat collection pipe and a photoresistor are arranged on the side, facing the sun, of the reflecting plate, and the photoresistor is used for detecting the illumination intensity change and is connected with a fixed resistor in series. The voltage division circuit is connected to the two ends of a power supply and is used for generating different partial voltages according to the change of the resistance value of the photoresistor; the microcontroller is connected with the voltage division circuit and is used for detecting the change of the voltage at the two ends of the photoresistor in the voltage division circuit and judging whether the voltage exceeds a set threshold value or not; and the motor driver is connected with the microcontroller. According to the invention, the overall working efficiency can be improved by accurately tracking the sun.

The invention discloses an electronic device and a voltage leakage circuit, the electronic device comprises a control circuit and a power circuit, the control circuit is connected with the power circuit and is used for controlling the power circuit to perform leakage or stop leakage, and the control circuit comprises a voltage division circuit; the comparison circuit is connected with the voltage division circuit and is used for receiving the first voltage from the voltage division circuit and comparing the first voltage with a preset reference voltage; the driving circuit receives the first reference voltage, is connected with the comparison circuit and the power circuit, and is used for outputting the first reference voltage to the power circuit when the first voltage is greater than or equal to the reference voltage so as to control the power circuit to discharge; one end of the hysteresis circuit is connected with the power circuit, the other end of the hysteresis circuit is connected between the voltage division circuit and the comparison circuit, and the hysteresis circuit is used for increasing the first voltage when the driving circuit outputs the first reference voltage to the power circuit. The power circuit is controlled through the voltage division circuit, the comparison circuit and the driving circuit, the cost can be reduced, and the occupied space is small.

The invention discloses a final-stage voltage tracking anti-clipping circuit for an audio power amplifier, and relates to the technical field of power amplifiers, and the circuit comprises a voltage division circuit which is used for receiving final-stage voltage from target power amplifier equipment and generating a combined voltage signal; the audio attenuation module is used for receiving an audio input signal and a final-stage voltage, and judging whether amplitude limiting modulation is carried out on the audio input signal or not to complete power amplifier output by judging whether a starting signal is received or not; and the starting judgment module is used for receiving the combined voltage signal and the first output signal, and comparing the combined voltage signal with the first output signal to generate a starting signal. According to the invention, the collected final-stage voltage of the target power amplifier is set as the dynamic amplitude limiting threshold, so that an over-high signal can be effectively suppressed to a safe range quickly when the power supply drops instantaneously, and the effects of avoiding hearing deterioration caused by power amplifier signal waveform truncation and avoiding potential safety hazards caused by amplitude limiting and topping to the loudspeaker are achieved.

A measuring device for has a housing, a measuring circuit board, and a communication circuit board. The measuring circuit board has a voltage connection, a voltage divider, a CT connection for connecting an external current transformer, a measuring chip connected to the voltage divider and the CT connection for determining electrical quantities and outputting as measurement data to a first part of a plug connector. The communication circuit board is connected to a second part of the plug connector, which together with the first part connects the communication circuit board and the measuring circuit board, a data communication chip connected to the second part and electrically isolated to receive the measurement data from the measuring chip, where a galvanic isolation between the measuring chip and the data communication chip is provided on the communication circuit board, a data connection connected to the data communication chip and a user interface.

The invention discloses a high-voltage sampling system and method. The high-voltage sampling system comprises a switch control module, a voltage dividing module, a first monitoring module, a high-voltage sampling module and a main control module, in the voltage dividing module, a first-stage voltage dividing unit is electrically connected with a high-voltage bus through a switch control module; the second-stage voltage dividing unit and the first-stage voltage dividing unit are electrically connected to a first voltage dividing node; the third-stage voltage dividing unit and the second-stage voltage dividing unit are electrically connected to a second voltage dividing node; the first monitoring module is used for monitoring the voltage of the first voltage dividing node, controlling the switch control module to be switched off when the voltage of the first voltage dividing node is abnormal, and providing a first feedback signal for the main control module; the high-voltage sampling module is used for collecting the voltage of the second voltage dividing node and providing a high-voltage sampling signal for the main control module; and the main control module is used for controlling the switch control module to be switched off according to the first feedback signal when the voltage of the first voltage division node is abnormal. By adopting the technical scheme, the safety and the reliability of the high-voltage sampling system are improved.

An oscillator circuit, a corresponding radar sensor, a vehicle, and an operating method are disclosed. An oscillator includes a tunable resonant circuit having an inductor and a variable capacitor coupled between a first node and a second node, and a set of capacitors selectively coupled between the first node and the second node. An input control node receiving an input control signal is coupled to the variable capacitor and the set of capacitors. The tunable resonant circuit is tunable based on the input control signal. A biasing circuit biases the tunable resonant circuit to generate a variable frequency output signal between the first node and the second node. A voltage divider generates a set of different voltage thresholds, and a set of comparator circuits having hysteresis compares the input control signal with the set of different voltage thresholds to generate a set of control signals. The capacitors in the set of capacitors are selectively coupled between the first node and the second node according to the control signals in the set of control signals.

The invention discloses a switching-in circuit with a self-adaptive voltage class and a double check logic. The switching-in circuit comprises a high-precision voltage division module, a double-redundancy sampling framework and a double sampling judgment logic executed by an MCU (Microprogrammed Control Unit), the high-precision voltage dividing module adopts a resistance network matched with a temperature coefficient, and can accurately divide input voltage in a wide temperature range; the double-set redundancy sampling architecture performs parallel sampling on the same path of input signals through two sets of completely independent signal conditioning loops, ADCs, digital isolation chips and isolation power supplies to form a physically isolated redundancy channel; the dual sampling discrimination logic executed by the MCU verifies a dual-channel sampling result based on a logic voting mechanism, and finally outputs a reliable input state or an abnormal alarm; according to the invention, through adaptive voltage design and redundancy check, high reliability is ensured, meanwhile, the requirements for spare parts of equipment of different voltage grades are remarkably reduced, and the inventory management cost is effectively reduced.

The invention discloses a high-voltage electric pulse cracking coal rock stress shock wave monitoring device which comprises a high-voltage pulse capacitor, a voltage divider, a high-voltage pulse switch, a high-voltage pulse cracking generation chamber, a high-voltage probe, a Rogowski coil and an oscilloscope. A test piece is fixed in the high-pressure pulse cracking generation chamber, a circle of test piece clamping assembly corresponding to the test piece is arranged in the high-pressure pulse cracking generation chamber, needle-shaped electrodes are arranged on the two sides, not provided with the test piece clamping assembly, of the test piece, and a piezoelectric pressure sensor is arranged on the high-pressure pulse cracking generation chamber. The detection signal output ends of all the piezoelectric pressure sensors are connected with the pressure detection signal input end of the stress wave signal collector, and a Faraday cage used for covering the piezoelectric pressure sensors is arranged in the high-pressure pulse fracturing generation chamber. The propagation characteristics of the high-voltage electric pulse stress shock waves in the coal rock mass can be accurately and directly captured in real time, and accurate and reliable data support is provided for deep research on a high-voltage pulse electric crushing mechanism.

The utility model belongs to the technical field of electronics, and relates to a detection circuit for high-voltage measurement of insulation resistance based on a solid-state optocoupler relay, when control signals output by an MCU in the detection circuit are HVPI NIOPP and HVP + I NIO, U27 and U34 in the detection circuit are conducted, and a voltage follower U29A is used for measuring the voltage U1 of a total voltage negative to a shell CAMP; when the control signals output by the MCU in the detection circuit are HVPI NIO and HVP-I NIO, U31 and U44 are conducted, and a voltage follower U29B measures the voltage U2 of the total voltage directly facing the shell CAMP; a series connection mode of U36, U27, U31, U34 and U44 is adopted, large voltage is increased, current in a loop is reduced during detection, and the withstand voltage value of the detection circuit is improved; a divider resistor group is used for dividing voltage, and a voltage follower is added, so that coupling of external interference is reduced, and the measurement precision is improved; and an isolated power supply mode is adopted, so that the complete isolation of the battery end and the MCU processing end is met.

The invention relates to the technical field of switching power supply, and discloses a switching power supply constant-current protection circuit and a protection method thereof.The switching power supply constant-current protection circuit comprises an environmental parameter sensing module which collects current signals of a constant-current output loop through a shunt resistor and a differential amplifier, collects input voltage through a resistance voltage-dividing network and collects temperature through a thermistor; the dynamic threshold value generation module is used for receiving the current signal and the environment parameter and generating a dynamic current protection threshold value to maintain constant current output; the AI prediction protection module is used for sampling current signals, extracting high-frequency energy characteristics through frequency domain analysis and comparing the high-frequency energy characteristics with a dynamic current protection threshold value; a digital twin monitoring module; and a protection execution module. Temperature parameters are collected in real time, polynomial fitting calculation is executed, the nonlinear characteristic of a thermistor is converted into a linear compensation coefficient, a protection threshold value is dynamically generated in combination with a current effective value and input voltage fluctuation, and self-adaptive drift compensation of a constant-current protection point in a full temperature range is achieved.

A method for detecting movement of a vehicle body component moveable by an electric motor having a rotor and a three-phase stator, and a motor vehicle. The method includes: loading two stator phases with a pulse-width-modulated voltage and maintaining a third stator phase at a free-floating state; monitoring the third stator phase as a measuring point for an inductive voltage divider formed using the two stator phases; and detecting movement of the vehicle body component when an electric signal at a measuring point or a variable derived from the electric signal exceeds a specified threshold value. The motor vehicle includes a control device that is operable to perform the method.

The invention discloses an aging test circuit and system of a vacuum arc-extinguishing chamber comprehensive mode, and relates to the technical field of high-voltage power equipment. The circuit comprises a booster circuit, a rectifier bridge, a voltage divider, a first high-voltage switch, a capacitor tower, a reactor group, an ignition device, a frequency modulation resistor, a frequency modulation capacitor, an auxiliary switch, a second high-voltage switch, a first transformer, a variable-frequency power supply, a detachable vacuum arc-extinguishing chamber and a direct-current measuring resistor. The circuit can adjust the stored energy of the capacitor tower and the voltage of the variable-frequency power supply according to the ablation condition of a contact in the vacuum arc-extinguishing chamber, so as to adjust the magnitude and frequency of the current released by the capacitor tower during an aging test and the magnitude and frequency of the voltage released by the transformer. Therefore, aging energy of large current / or small current / or voltage with different frequencies is applied during an aging test, and the aging energy and the action mode of the energy are ensured to be matched with the current state of the contact by controlling the energy applying mode and the energy applying frequency under different contact opening distances.

The utility model provides a capacitor module for solving battery abnormity of a power utilization acquisition terminal in a low temperature scene, a voltage determination circuit, a super-capacitor charging circuit and a boost circuit are integrated on a printed board, the voltage determination circuit comprises a chip U1 and a divider resistor, the super-capacitor charging circuit comprises a chip U2 and a shunt resistor, and the boost circuit comprises a chip U1 and a chip U2. According to the boost circuit, an internal logic power supply pin of a chip U3 is connected with a BOOST circuit output by the BOOST circuit, a reset signal pin of a chip U1 is connected with enable signal pins of a chip U2 and the chip U3, a power supply pin of the chip U1 is connected with a nickel-metal hydride battery charging circuit, an input end of the chip U2 is connected with the nickel-metal hydride battery charging circuit, an output end of the chip U2 is connected with a super capacitor, and the super capacitor is connected with a power supply pin of the chip U1. The input end and the output end of the chip U3 are both connected with the nickel-metal hydride battery charging circuit, and a switch pin of the chip U3 is connected with the super capacitor. By adopting the technical scheme, the cost is lower than that of a low-temperature nickel-metal hydride battery, and a nickel-metal hydride battery pack can be directly replaced.

The invention provides a power-on reset circuit and a chip. The power-on reset circuit comprises a power-on module, and the power-on module is used for controlling connection or disconnection of a first end and a second end of the power-on module based on a control voltage and a power supply voltage of a first power supply end, and adjusting an output voltage of the power-on module based on the change of the power supply voltage when the power-on module is connected; the voltage dividing module is used for providing control voltage to the power-on module; the conversion module is used for converting the output voltage of the power-on module to output a reset control signal under the condition that the output voltage of the power-on module is changed to the overturning voltage of the conversion module; the first inverting module is used for converting the reset control signal to output a reset signal. Therefore, the power consumption generated in the circuit can be reduced while the circuit area is saved.

The invention discloses a converter transformer partial discharge monitoring method and system based on a valve side bushing end screen voltage divider, and relates to the technical field of converter transformer partial discharge monitoring, and the method comprises the steps: setting a non-intrusive signal collection point; extracting a high-frequency partial discharge signal from the voltage signal of the valve side bushing end screen voltage divider; and processing and analyzing the high-frequency partial discharge signal. According to the method, the partial discharge signals of the converter transformer can be sensitively and accurately monitored in a non-intrusive signal acquisition mode, the anti-interference capability is high, the remarkable advantages are achieved, equipment transformation and increase of sensors are avoided, and the safety risk and the installation and maintenance difficulty are reduced; an accurate signal extraction and processing technology is adopted, so that the monitoring sensitivity and the signal quality are greatly improved; the system is simple in structure, convenient to install and maintain and suitable for long-term field application.

The present invention discloses an LDO circuit with soft start and foldback current limiting protection functions, including a bandgap reference module, a soft start module, a voltage selection module, a current limiting protection module, a first error amplifier, an output power tube, a first voltage divider resistor, and a second voltage divider resistor; the present invention realizes that there is no overshoot when the LDO is powered on, and the power consumption of the chip after entering the foldback current limiting is greatly reduced, thereby ensuring the safety of the chip. By reusing the control signal of the soft start circuit, the problem of failure to start with a constant current load in the traditional foldback protection circuit is solved, and the ability to power on with a load is improved. At the same time, it can be easily adjusted by V SET The voltage can flexibly adjust the current limit value at power-on according to the load requirements, providing good protection for the chip while meeting the application requirements.

The present invention discloses a hybrid switching converter with a single inductor and multiple outputs and a control method thereof, configured to convert an input voltage to a first and a second output voltages. The hybrid switching converter includes: a sub-switching converter, which converts the input voltage to an intermediate voltage; a first and a second output switches, which conduct the intermediate voltage during a first and a second inductance periods, respectively, to generate the first and second output voltages. The sub-switching converter comprises: a switched capacitor voltage divider circuit, which controls multiple switches through pulse-width modulation (PWM) signals to generate two divided voltage levels in each inductance cycle for supplying an inductor therein; and a control circuit, which generates PWM signals to control the multiple switches and the output switches in a time-division manner, and regulates the output voltages to target values according to output voltage feedback signals.

The invention relates to an SPI (Serial Peripheral Interface) lamp bead number detection method, which comprises the following steps of: A, cascading a plurality of lamp beads to form an LED (Light Emitting Diode) lamp bead link, and controlling the on-off of each lamp bead through an MOS (Metal Oxide Semiconductor) tube driving circuit; b, the ADC detection module collects current signals through divider resistors R1 and R2 of the resistance divider network; c, dynamically calibrating a zero lamp bead reference voltage V, setting a current change threshold value epsilon, measuring a zero lamp bead reference current I, and recording a single lamp bead standard current delta I = I-I when the first lamp bead is lightened; d, sequentially lightening the single lamp beads one by one through the MOS tube driving circuit, dynamically recording the characteristic voltage delta V of the single lamp bead through the main controller when one lamp bead is lightened, comparing the current change value delta I'with the current change threshold epsilon, establishing a current change curve, recording the lamp bead with the current change value within the epsilon range as a normal lamp bead, and recording the lamp bead with the current change value within the epsilon range as a normal lamp bead. And judging the number of the normal lamp beads according to the dynamic current of the lamp beads and the linear change relationship between the upper and lower measuring points of the resistance potential-dividing network when the detected voltage is regressed to V + / -epsilon.