29 results about "Lamp current" patented technology

The invention discloses a thermal printer paper type identification and paper shortage detection method and system based on a single reflection sensor. MN2000 is provided with a receiving lamp current detection circuit and a transmitting lamp current control circuit; the receiving lamp current detection circuit comprises a Q2, the GND end of the Q2 is grounded and then connected with a capacitor in series, the other end of the capacitor is connected with a first resistor, the first resistor is connected with a Vdd, the VPS end of the Q2 is connected with a second resistor, the second resistor is connected with the Vdd, the PS end of the Q2 is connected with a diode, and the diode is connected to a terminal 19 of the MN2000; and the emission lamp current control circuit is connected from a No.19 terminal of the MN2000, then connected to an RC filter circuit consisting of an R2009, an L2001 and a C2040, then connected in series with a third resistor R2035, and then connected to a base electrode end of the Q2000, and the Q2000 is connected to a VPS signal end. A transmitting lamp current control circuit and a receiving lamp current detection circuit are additionally arranged on the microprocessor, so that label detection and paper shortage detection can be realized at the same time.

The invention provides a system for vehicle lamp fault detection and a control method, and belongs to the technical field of vehicle lamp fault detection.The system comprises a vehicle lamp, an instrument panel, a fault detection module and a main control module, the vehicle lamp is connected with the fault detection module, and the output end of the fault detection module is connected with the input end of the main control module; the output end of the main control module is connected with the input end of the vehicle lamp and the input end of the instrument panel. The fault detection module detects the current flowing through the vehicle lamp through a current detection line, and when the current flowing through the vehicle lamp is continuously lower than a vehicle lamp current abnormal threshold for multiple times, the fault detection module outputs a fault feedback signal to the main control module. After the main control module judges that the automobile lamp breaks down, the main control module controls the automobile lamp and the instrument panel to give an alarm. The automobile lamp damage condition is accurately fed back, the error feedback risk caused by the low-voltage or low-temperature environment is reduced, meanwhile, a driver is reminded when a fault occurs, and safety is improved.

The invention discloses a circuit and a method for time-sharing detection of analog quantity of current and voltage of a lamp, belongs to the technical field of current and voltage control of a semiconductor process, and aims to carry out whole-course measurement on bulbs powered by AC (Alternating Current) or DC (Direct Current), the number of bulbs connected in series in each loop is not limited, and a single bulb or a plurality of bulbs connected in series can be detected. And current data can be used as a group of parameters to assist in judging process data. The method comprises the following steps: detecting a current value, comparing the detected current value with Spec, and if the detected current value exceeds the Spec, calculating a voltage value in a corresponding loop so as to accurately locate which lamp has a fault. According to the invention, AD two-stage multiplexing is adopted, which loop problem is positioned by current is detected firstly, and then the specific position is positioned by measuring voltage. Current and voltage values in a loop can be detected, two-stage AD sampling is adopted, the sampling efficiency is improved, the workload of an MCU is reduced, and fault positioning of each lamp is more efficient and accurate.

The utility model discloses an integrated detection tool for a vehicle lamp. The integrated detection tool comprises a positioning module, a current detection module, a marking module and an air tightness detection module, wherein the positioning module is used for fixing a vehicle lamp; the current detection module is arranged on one side of the positioning module and is used for detecting the working state of the vehicle lamp after different currents are introduced; the marking module is arranged on one side of the positioning module and used for marking the vehicle lamp. The air tightness detection module is connected with the current detection module and used for detecting the air tightness of the vehicle lamp. According to the utility model, the vehicle lamp detection efficiency is greatly improved, and the production cost is reduced.

The present invention discloses an LED constant current driving system without an iron core in the PT broken state, which includes a non-linear saturation controlled voltage source, a transformer without an iron core, an uncontrolled rectification module, an output filter capacitor, m series-connected LED lights, a current sampling circuit, a brightness signal conversion module, an error calculation module, a PI compensator, and a PWM generator; the brightness signal conversion module converts the input brightness value B×100% into an output current set value i ref ; the error calculation module calculates the difference i LED between the current signal i ref and the output current set value i err , uses the PI compensator to perform compensation calculation on the difference i err to obtain an output phase shift angle θ, and the PWM generator outputs a PWM signal according to the phase shift angle θ to control the non-linear saturation controlled voltage source, thereby realizing the adjustment and control of the brightness of the LED lights. The present invention realizes the iron core removal of the isolation transformer in the LED constant current driving system and has a good application effect.

A method for operating a two-electrode discharge lamp for a projection arrangement, wherein the discharge lamp is supplied with an alternating current (I) with a mean frequency and a predetermined waveform having a predetermined commutation scheme (16a; 16b), wherein the predetermined commutation scheme (16a; 16b) is defined by a predetermined temporal sequence of commutations (K) of the lamp current (I), wherein the commutation scheme (16a; 16b) has a current segment (18a, 18b, 18c, 18d and 18e combined, 18f) between each pair of commutations (K), wherein the absolute values ​​of the current in at least two of the current segments (18a, 18b, 18c, 18d and 18e combined, 18f) are different, and wherein the predetermined commutation scheme (16a; 16b) is repeatedly deviated from the predetermined sequence at at least one predetermined time interval. Commutation scheme (16a;16b) is deviated from by at least one direct current phase (20) with a predetermined time duration, characterized in that the at least one predetermined time interval is a maximum of 50 seconds.;

A lamp current detection device comprises a control unit and a power connection unit, the control unit is connected with the power connection unit, after the power connection unit is connected with a lamp, detection is carried out through the control unit, a detection structure is output and displayed, a plurality of detection circuits are arranged in the control unit, each detection circuit comprises a main circuit and a plurality of auxiliary circuits, and the main circuits are connected with the auxiliary circuits. The main circuit and the plurality of auxiliary circuits are respectively connected to power connection terminals of the power connection unit, the main circuit and the plurality of auxiliary circuits are arranged in the control unit through cooperative work of the control unit and the power connection unit, each auxiliary circuit and the main circuit can form an independent detection circuit, a plurality of circuit modules in the lamp can be detected at the same time, and the detection efficiency is improved. Synchronous detection of parameters of all the modules is achieved, the detection time is greatly shortened, the detection efficiency is remarkably improved, and the production progress of a lamp production line is effectively accelerated.

To provide a lighting device for a discharge lamp and an irradiation device that can save energy and can perform appropriate lighting.SOLUTION: A lighting device applies drive voltage at a predetermined frequency to a hot-cathode discharge lamp, and is provided with: an inverter circuit; a resonance circuit having a first resonance circuit that is connected, on an input side, with an output side of the inverter circuit and connected, on an output side, with a pair of electrodes of the hot-cathode discharge lamp, and resonates lamp current, and a second resonance circuit that resonates filament current flowing in the electrodes; a switching circuit that is connected between the second resonance circuit and the electrodes, and switches between application of the filament current and stop of the application; and a control circuit that controls the switching circuit. At least one of before lighting and at start-up, the control circuit executes the application of the filament current, and after the start-up, selects and executes one of the application of the filament current and the stop of the application on the basis of input data of the hot-cathode discharge lamp.SELECTED DRAWING: Figure 1

The present invention discloses a control method, a control circuit and a lighting circuit of a lighting circuit. The lighting circuit comprises a linear adjustment tube. The load of the lighting circuit is an LED lamp. An AC input power source is rectified by a rectifier circuit to obtain a rectified voltage. The linear adjustment tube is connected in series with the LED lamp. The rectified voltage supplies power to the LED lamp. When the rectified voltage is greater than or equal to a first voltage, the linear adjustment tube is turned on and the current of the LED lamp is controlled to be a first current. Timing starts from when the LED lamp is turned on or when the current of the LED lamp is the first current. When the timing reaches a first time or when the rectified voltage is greater than or equal to a second voltage, the linear adjustment tube is controlled to be turned off, and the current of the LED lamp is zero. In the next half power frequency cycle, when the rectified voltage is greater than or equal to the first voltage, the linear adjustment tube is turned on again.

The utility model relates to the field of LED lamp control, in particular to a DMX landscape lamp current expanding circuit. A DMX landscape lamp current expanding circuit comprises an illuminating lamp control chip U1 and a chip U2. The chip U2 outputs a PWM signal to the lighting lamp control chip U1 so as to control a lighting LED lamp string; the illuminating lamp control chip U1 is a DMX512 chip of which the model number is SM19522PH; the DMX landscape lamp current expanding circuit further comprises an MOS switch circuit. And the chip U2 outputs a PWM signal and transmits the PWM signal to the illuminating lamp control chip U1 through the MOS switching circuit. The beneficial effects of the utility model are that the MOS switch circuit is added, and the MOS switch circuit is utilized to indirectly control the current expanding circuit, thereby improving the reliability. And the problem that a DMX chip is impacted by current and the whole lamp goes wrong due to the fact that one current expanding circuit breaks down is avoided.

The utility model relates to the technical field of garden lighting, in particular to a garden lamp with an insect repelling function, which comprises a support frame, one side of the support frame is connected with a solar panel, the bottom of the solar panel is provided with a shielding shell, the bottom of the shielding shell is provided with a connecting rod, one side of the connecting rod is provided with a protective rod, and the protective rod is connected with the support frame. A current net is arranged on one side of the protection rod, a supporting base is installed at the bottom of the current net, an inducing lamp is installed at the upper end of the supporting base, a garden lamp is arranged at the upper end of the inducing lamp, a fixed base is installed at the bottom of the connecting rod, a rotating handle is installed on one side of the fixed base, and a stop block is installed at the bottom of the rotating handle. According to the improved garden lamp, a current net and a luring lamp are additionally arranged, the current net conducts current killing on mosquitoes through current, the mosquitoes are prevented from influencing passers-by, and the collecting box and a check block are additionally arranged so that the collecting box can be rapidly disassembled and replaced.

The present invention provides a calculation method, a calculation device and an LED signal machine for LED damage rate, wherein the calculation method comprises: defining five signal machine lighting states: light off, red light on, green light on, yellow light on, and red and yellow light on; respectively collecting the current I passing through the filament relay DJ and the second filament relay 2DJ in the signal machine lighting circuit; DJ and I 2DJ , where the current passing through DJ is recorded as DJ current, and the current passing through 2DJ is recorded as 2DJ current; when the signal light is in the red light, then: Red light LED damage rate = (I 0H ‑I DJ )*X% / (I 0H ‑I X%H ); where I 0H Refers to the reference lighting current of the red light when the damage rate is 0; X% is the reference damage rate; I X%H Refers to the reference lighting current when the damage rate of the red light is X%; similarly, calculate the LED damage rate when the green light, yellow light, red and yellow light are on.

Driver circuit for operating a light source, preferably at least one LED, comprising a galvanically isolated converter switched on the primary side by a control unit (SE', SE'') by means of at least one controlled switch unit (S), the switch unit (S) with a first inverter switch (Q1) and a second inverter switch (Q2), which feeds a rectifier (D1, D2) from which the light source can be supplied, wherein a detection circuit (E', E'') for indirect detection of the current on the secondary side of the converter comprises a transformer (L3_1, L3_3) with at least one primary-side winding (L3_1), wherein the detection circuit (E', E'') includes an active detection rectifier (AG, AG'), wherein the control unit (SE', SE'') activates / deactivates a first diagonal of the active rectifier (AG, AG') synchronously with the first inverter switch (Q1), and wherein the control unit (SE', SE'') activates / deactivates a second diagonal of the active rectifier (AG', AG'') synchronously with the second inverter switch (Q2), and wherein only the first or the second diagonal is active at any given time, wherein the secondary winding (L3_3) of the transformer (L3_1, L3_3) is part of each of the diagonals of the active sensing rectifier (AG, AG'), where, by switching the tap of the secondary winding (L3_3), the fault-inducing "reverse current" is measured as a negative current, so that the lamp current is controlled by the control unit (SE'') by a corresponding control of the switch unit (S) on the primary side of the circuit, wherein the parameter representing the current through the light source is detected by means of an integration circuit (I), wherein a feedback signal is detected at the midpoint of a voltage divider formed from two resistors (R1, R2) by the control unit (SE''), where the voltage divider (R1, R2) is connected in parallel with a capacitor (C3), and wherein the rectified output signal from the active detection rectifier (AG') is supplied to the parallel circuit at the higher potential terminal of the capacitor (C3).

This utility model belongs to the field of power supply circuit technology. It provides an ultraviolet lamp comprising a power supply module, a transformer module, a rectifier module, a filter module, a voltage regulator module, and a drive load module; these modules are connected sequentially. The ultraviolet lamp provided by this utility model uses a transformer module to convert the AC power output from the power supply module into unidirectional pulsating DC power. The filter module and voltage regulator module are connected between the main circuit and the load, effectively filtering out the AC component in the pulsating DC voltage. This provides a high starting voltage for the ultraviolet lamp and limits the lamp current to a stable range, enabling effective and stable high-intensity output for better sterilization.

The present invention relates to a dimmer and a lamp thereof. The dimmer includes a rectifier filter module, a 5V voltage regulator module, a dimming control module, a wireless receiving module, an overcurrent detection module and a single-chip control module; the overcurrent detection module includes a control chip, a sampling circuit for collecting circuit current values, an operational amplifier circuit for calculating the sampled current signal and a comparison circuit for comparing the current signal with a set current value; the signal output end of the control chip is connected to the detection signal input end of the single-chip control module. The overcurrent detection module of the dimmer obtains the current of the lamp and compares it with the set current to know whether the lamp is in a short-circuit state. When the lamp is in a short-circuit state, the single-chip control module disconnects the connection with the dimming control module, that is, disconnects the connection between the dimmer and the lamp, so that the dimmer will not be damaged when the lamp is short-circuited.

The invention relates to the technical field of municipal lighting public service application, in particular to a municipal lighting street lamp electric leakage monitoring and positioning system which comprises a municipal street lamp public service platform, a distribution box gateway and a street lamp electric leakage monitoring terminal. The municipal street lamp public service platform is used for displaying the working state of the street lamp; the distribution box gateway comprises a main processing module, a LoRa communication module, a 4G / 5G network communication module, a Beidou positioning module and a power supply module; the street lamp electric leakage monitoring terminal comprises a main processing module, a LoRa communication module, a residual current monitoring module, a street lamp current and voltage monitoring module, a lamp control module, a temperature sensor and a water sensor. The system has the following beneficial effects: the system is accurate in electric leakage positioning, low in communication cost and power consumption, high in installation and maintenance efficiency, high in reliability and safety, capable of supporting an energy-saving control strategy, and remarkable in economic benefit.

The utility model discloses equipment for detecting a hard connection type control auxiliary window glass lifting switch, which comprises an equipment main body, one side of the equipment main body is provided with a light emitting diode, one side of the equipment main body is provided with an LED lamp, one side of the equipment main body is provided with a voltmeter, one side of the equipment main body is provided with an ampere meter, and the other side of the equipment main body is provided with a power supply. One side of the equipment main body is provided with a power switch, the other side of the equipment main body is provided with a power line interface, and the hard connection type auxiliary window glass lifting control switch can be detected through the arranged light emitting diodes, the three-color LED lamps, the ampere meter, the voltmeter and the circuit board. The device is simple in structure and easy to improve and upgrade, can simplify the field inspection process of a finished product, shortens the inspection time, improves the efficiency, can directly detect the on-off performance, the conductive stability performance, the voltage drop under rated current and the on-off logic of the auxiliary rocker detection switch at the same time, and greatly facilitates the use of workers.

The utility model provides an LED constant current drive circuit with fault feedback, comprising a power supply module for providing electric energy, the power supply module is respectively connected with an LED circuit and a comparison circuit, the output end of the comparison circuit is connected with the LED circuit, and the comparison circuit is used for adjusting the circulating current on an LEF circuit; the power supply module comprises a KL30-prot port for providing electric energy, the LED circuit comprises an LED lamp and a triode T1, an input end of the LED lamp is connected with the KL30-prot port, an output end of the LED lamp is connected with a collector electrode of the triode T1, a base electrode of the triode T1 is connected with the comparison circuit, and the comparison circuit adjusts the conduction degree of the comparison circuit by adjusting the voltage of the base electrode of the triode T1. According to the utility model, the current stability of the vehicle lamp can be improved.

Electronic power supply module for a short-arc xenon lamp, comprising a first power supply (1), delivering a first DC voltage, referred to as the "operating voltage". According to the invention, the electronic module comprises a voltage booster (12) delivering a second DC voltage, referred to as the "ignition voltage", which is added to the operating voltage, the sum of the two voltages defining a supply voltage, a low-frequency filter (3) to filter the supply voltage and a current switch (2) to cancel the ignition voltage above a predefined lamp current threshold.

The utility model discloses a trailer detection circuit compatible with an LED lamp flasher, comprising a PNP triode Q6 and a PNP triode Q7, the base electrode of the PNP triode Q6 is connected with a left steering trailer control IO through a resistor R24, the emitter electrode of the PNP triode Q6 is connected with one end of a resistor R73, and the other end of the resistor R73 is respectively connected with one end of a resistor R65 and the negative electrode of a diode D22. According to the utility model, the output of the trailer detection circuit is controlled through the two triodes, when the steering switch is not turned on, the current flowing through the LED lamp is zero, and the LED lamp is not lightened, and only when the steering switch is turned on, the triodes are conducted for several milliseconds, so that whether the trailer exists or not is detected. According to the trailer detection circuit compatible with the LED lamp flasher, the working state of the light of the trailer can be monitored in real time, faults can be found in time, a driver is reminded to maintain the trailer, and therefore the driving safety of the trailer is improved.

The utility model relates to the technical field of gas analysis, in particular to a light source control system and a gas analyzer applying the light source control system, and the light source control system comprises a light intensity detection module, a first controller module, a current detection module, a second controller module and a power supply module, and the second controller compares the lamp current signal with the first control signal and then outputs a second control signal for performing closed-loop control to stabilize the light intensity of the light-emitting module to the power supply module. According to the utility model, light intensity stability of the light-emitting module is realized through closed-loop control based on zinc lamp light intensity, real-time control of the light-emitting module can be realized, and meaningless waste of the service life of the light-emitting module caused by the fact that the light-emitting module cannot be used due to too fast light intensity attenuation at the initial working stage can be avoided; and meanwhile, self-adaptive adjustment of light-emitting modules with different batches and performances can be realized, pre-aging is not needed, and the labor intensity of assembling and debugging personnel and the later equipment maintenance cost are greatly reduced.

Device (V) for controlling at least one light source (LED), comprehensive - a lamp driver (T) with at least two channels (ch), - a measuring device (M) and - a control unit (CU), wherein each channel (ch) is assigned a PWM modulation unit (PWM), and wherein each of the PWM modulation units (PWM) can be controlled separately and individually by the control unit (CU), and wherein each of the PWM modulation units (PWM) is configured to switch exactly one current source (IQ), and wherein each of the current sources (IQ) is designed to be dependent on a PWM period (t PWM ) periodic PWM output signal of its associated PWM modulation unit (PWM) to supply a light source (LED) with electrical energy, whereby an electrical lamp current generated by the associated current source (IQ) flows through the lamp (LED), and / or wherein an electrical lamp voltage applied by the associated current source (IQ) is applied to the lamp (LED) relative to a supply line (VL) of the current sources (IQ), and wherein the respective PWM output signal of each PWM modulation unit (PWM) comprises a PWM pulse with a rising edge and a falling edge, and wherein a switch-on time (t E ) correlates with the rising edge or the falling edge of the PWM pulse, and where the PWM period (t PWM ) corresponds to a time period from the rising edge of the PWM pulse to the rising edge of the immediately following PWM pulse, and where the control unit (CU) is configured to send a control signal (CS) to the PWM modulation units (PWM) in order to determine the respective switch-on time (t E ) of the PWM pulses output by the control unit (CU) addressed PWM modulation units (PWM) per PWM modulation unit (PWM) separately and individually to each other within the PWM period (t PWM ) in such a way that - a resulting total current (i(t)) of the lamp currents and / or a total voltage (V Ges ) of the lamp voltages in the supply line (VL) compared to a reference potential (GND) over the PWM period (t PWM ) corresponds to a nearly constant value and / or - an effective value of an alternating signal component of the resulting total current (i(t)) of the lamp currents and / or the total voltage of the lamp voltages in the supply line (VL) of the current sources (IQ) relative to the reference potential (GND) over the PWM period (t PWM ), wherein the measuring device (M) is designed to record a measured value (MW), wherein the measured value (MW) is a measured value for the resulting total current (i(t)), and / or the measured value (MW) is a measured value for the total voltage (V Ges ) in the supply line (VL) of the current sources (IQ) compared to the reference potential (GND), wherein the control unit (CU) is arranged to send the control signal (CS) depending on the measured value (MW), wherein the control unit (CU) is arranged to send the control signal (CS) when - a deviation of the measured value (MW) from a predetermined and / or calculated mean value (MMW) exceeds a predetermined first threshold value, or - a deviation of a direct signal component (GSA) of the measured value (MW) from a predetermined comparison value is greater than a predetermined second threshold value, and wherein the control unit (CU) is configured to carry out this method until the deviation of the measured value (MW) from the mean value (MMW) is less than or equal to the first threshold value or until the deviation between the direct signal component (GSA) and the comparison value is less than or equal to the second threshold value.

The invention relates to the technical field of LED lamp testing, in particular to a testing method and system for an LED lamp, and the method comprises the following steps: arranging a current sensor, fixing the current sensor at the input end of an LED lamp circuit, continuously monitoring and recording the current data of the LED lamp, and carrying out the data cleaning and format arrangement at the same time. According to the invention, the current sensor monitors the current data of the LED lamp in real time and carries out data cleaning and format arrangement, so that the high precision and reliability of the monitored data are ensured; statistical analysis of the abnormal fluctuation frequency and amplitude reveals the reason and potential trend of the abnormity. A time sequence prediction model is applied to predict the time point of performance degradation of the LED lamp, deep understanding of future performance changes is provided, the timeliness of maintenance measures is enhanced, and formulation of a maintenance plan is optimized. Through comparative analysis of the predicted value and the design standard, the health condition of the LED lamp can be comprehensively evaluated, so that the maintenance decision is more scientific.

The utility model provides a light bar for indicating the state of a charging pile, and belongs to the technical field of intelligent control. The lamp strip for indicating the state of the charging pile comprises a first LED lamp array, a plurality of second LED lamps, a current sensor, an illumination sensor, a first controller and a second controller. The second LED lamps are arranged around the first LED lamp array at intervals. The first LED lamp array comprises a plurality of first LED lamps which are arranged in sequence. The current sensor is used for being connected with an external charging pile. The current sensor is connected with the first controller. The first controller is connected with the first LED lamp array. And the illumination sensor is connected with the second controller. And the second controller is connected with the plurality of second LED lamps. The first LED lamp and the second LED lamp are different in light color. According to the invention, a safe indication mode can be provided, and the use safety and the use efficiency of the charging pile are improved.

The application discloses an ultraviolet disinfection device, a control method and a storage medium. The ultraviolet disinfection device comprises a control module, an ultraviolet lamp driving module, a plurality of ultraviolet lamps, a current sampling module and a light power detection module. The ultraviolet lamp driving module comprises a comparator and a plurality of MOS tubes. The output end of the control module is connected with the first input end of the comparator. The output end of the comparator is connected with the gate of the MOS tube. The drain of the MOS tube is used for connecting an alternating current power supply. The source of the MOS tube is connected with the positive pole of the ultraviolet lamp. The current sampling module comprises a first isolator and a plurality of sampling resistors corresponding to the ultraviolet lamps. The negative pole of the ultraviolet lamp is connected with one end of the sampling resistor. The other end of the sampling resistor is used for connecting the alternating current power supply. One end of the sampling resistor is connected with the input end of the first isolator. The output end of the first isolator is connected with the second input end of the comparator. The output end of the light power detection module is connected with the input end of the control module.

The utility model relates to an air purification control device. Comprising a power supply module used for converting 220V commercial power into one path of DC24V and one path of DC5V for output; the single-chip microcomputer control module is used for controlling on and off of the fan and the ultraviolet lamp, monitoring the current state and processing fault information; the fan driving module inputs the working current of the fan into an LM358 operational amplifier through a sampling resistor R1 for current detection; the ultraviolet lamp driving module adopts a triode and a relay to drive an ultraviolet lamp; the current detection module comprises a sampling resistor R1, a sampling resistor R2 and an LM358 operational amplifier and is used for processing working current signals of the fan and the ultraviolet lamp; and the fault indication module is used for prompting maintenance through an indication lamp on the panel when abnormal current of the fan or the ultraviolet lamp is detected. The technical problems that in the prior art, air purification or disinfection equipment is usually large in size and inconvenient to install and maintain, and meanwhile when the equipment breaks down, the equipment is difficult to monitor and maintain in time are solved.

The invention discloses a street lamp fault positioning system and method based on segmented current dynamic comparison, and relates to the technical field of electrical fault positioning. In the system, non-contact current monitoring nodes are deployed in a segmented manner according to a preset distance for a line where a street lamp to be detected is located; the current monitoring nodes are used for regularly collecting street lamp current data of corresponding road sections; the current monitoring node is in communication connection with the data processing center through the communication module so as to transmit acquired street lamp current data to the data processing center; and the data processing center judges a street lamp road section corresponding to the fault data deviating from the current dynamic baseline by a preset proportion by comparing and analyzing a difference value between the street lamp current data and the current data at the same moment in the historical data. According to the technical scheme of the invention, the method achieves the precise positioning of the fault road section of the street lamp, reduces the deployment cost of detection hardware, reduces the fault false alarm rate of the street lamp, and improves the deployment flexibility and efficiency of equipment.

Device for operating a discharge lamp, in particular for projection purposes, comprising: - at least one AC-operable discharge lamp with a first electrode and a second electrode and - a control device which is designed to provide at least two current waveforms (W1, W2) for controlling the discharge lamp, wherein the respective current waveforms (W1, W2) are characterized by a respective envelope curve (I L ) with respect to a lamp current to be controlled through the discharge lamp and by a respective polarity curve (K1, K2) with respect to the flow direction of the lamp current to be controlled, - a measuring device for determining a measured value (X) correlated with a state variable of the discharge lamp, which is suitable for enabling a conclusion to be drawn about a state of the electrode geometry of the first electrode and / or the second electrode, characterized by - an evaluation device for determining an evaluation characteristic (Y1, Y2) which characterizes the influence of one of the at least two current waveforms (W1, W2) on the electrode geometry of the first electrode and / or second electrode when driving the discharge lamp with one of the at least two current waveforms (W1, W2), - wherein the control device is designed to store the evaluation characteristic (Y1, Y2) determined for one of the at least two current waveforms (W1, W2) for the associated current waveform of the at least two current waveforms (W1, W2), and - in a first operating interval (22a), to select one of the at least two current waveforms (W1, W2) with the aid of the evaluation characteristic (Y1, Y2) stored for this purpose for control in a second operating interval (22b) following the first operating interval.

The invention provides a detection method for determining the content of vitamin B12 by atomic absorption spectrometry, which comprises the following steps: S1, digesting a specified amount of sample, destroying organic matters, dissociating cobalt element to form ions, and quantitatively diluting digestive juice by using a 1% nitric acid solution to obtain a to-be-tested sample solution; s2, the to-be-tested sample solution is subjected to flame atomic absorption spectrometry determination, the analysis spectral line of cobalt is 240.7 nm, the slit width is 0.5 nm, the lamp current is 5 ma, and a cobalt air core cathode lamp is used as a light source; s3, after the content of the cobalt element is measured, the content of vitamin B12 is calculated through the conversion coefficient; the method provided by the invention is simple in sample pretreatment, does not need complex separation and purification steps, and is high in sensitivity.