30 results about "Voltage alarm" patented technology

The invention relates to the field of vehicles, in particular to a tire pressure monitoring method, device and equipment, a vehicle and a readable storage medium. The method comprises the steps of obtaining first monitoring data recorded before a vehicle is started, wherein the first monitoring data comprises monitoring data of each tire of the vehicle; judging whether each tire is in a low-pressure state or not based on the first monitoring data; if any tire is in the low-pressure state, a low-pressure alarm instruction is generated, and the low-pressure alarm instruction is used for indicating the vehicle to output a low-pressure alarm signal. According to the invention, the timeliness of vehicle low-voltage alarm is improved.

The invention relates to the technical field of power supply management, and discloses a low-voltage detection circuit, and the circuit comprises a bias current unit which comprises a current mirror structure and is configured to mirror a reference current to generate a tail current; the delta Vth compensation low-voltage detection unit is respectively connected with the bias current unit, reference voltage and power supply voltage, and comprises a first PMOS (P-channel Metal Oxide Semiconductor) tube, a sixth NMOS (N-channel Metal Oxide Semiconductor) tube and a fifth NMOS tube which are sequentially connected in series, and a seventh NMOS tube which is bridged at the drain end and the source end of the sixth NMOS tube; wherein the source electrode of the first PMOS tube is connected with a power supply voltage, the source electrode of the fifth NMOS tube is connected with a tail current, and the grid electrodes of the first PMOS tube, the sixth NMOS tube and the fifth NMOS tube are all connected with a reference voltage; the grid electrode and the source electrode of the seventh NMOS tube are respectively connected with the drain electrode and the source electrode of the sixth NMOS tube, and the drain electrode of the seventh NMOS tube is connected with the power supply voltage; and the input end of the low-voltage alarm signal rectification phase inverter is connected with the grid electrode of the seventh NMOS tube, and the low-voltage alarm signal rectification phase inverter rectifies the detection voltage and outputs a low-voltage detection alarm signal. The circuit is small in area and low in static power consumption. The invention also discloses a chip.

This invention relates to a ground marking and cathodic protection integrated intelligent monitoring system for oil and gas pipelines, comprising a polarized test piece soil reference tube, a self-corroding test piece soil reference tube, a Mark signal sensor, a power supply, and a data acquisition recorder. The data acquisition recorder is equipped with a GPS positioning module and a communication module; the power supply has a low voltage warning function; the data acquisition recorder collects and processes cathodic protection parameters, stray current interference data, and pipeline corrosion rate monitored by the polarized test piece soil reference tube, self-corrosion potential monitored by the self-corrosion test piece soil reference tube, and low-voltage alarm signals output by the power supply, and also processes the electrical signals output by the Mark signal sensor to generate positioning commands that trigger the GPS positioning module to output position signals; this invention achieves high efficiency, high precision, high integration, and high intelligence in oil and gas pipeline operation and maintenance management, improving the accuracy of pipeline corrosion detection and cathodic protection detection and the level of intelligent management.

The application discloses a voltage detection method and device of a single-line power supply transformer substation. The voltage detection method of the single-line power supply transformer substation provided by the embodiment of the application is applied to a power system and is executed by a voltage detection device of the single-line power supply transformer substation. The method comprises the following steps: acquiring parameter information of a power supply transformer substation; determining a state parameter value of the power supply transformer substation according to the parameter information; determining a voltage state of the single-line power supply transformer substation according to the state parameter value of the power supply transformer substation; and outputting a loss-of-voltage alarm signal of the single-line power supply transformer substation according to the voltage state of the single-line power supply transformer substation. The technical scheme of the embodiment of the application determines the voltage state of the single-line power supply transformer substation by acquiring the parameter information of the power supply transformer substation, confirms whether the loss-of-voltage alarm signal needs to be sent, and realizes accurate judgment on whether the single-line power supply transformer substation loses voltage, thereby preventing the single-line single transformer substation from sending the loss-of-voltage alarm by mistake during power supply via a bypass bus and during a related dispatching operation process.

The utility model relates to the technical field of lithium iron phosphate battery low-voltage alarm devices, and provides a communication-free lithium iron phosphate battery low-voltage alarm device, which comprises an equipment shell and a lithium iron phosphate battery, two groups of electric wires are fixedly arranged on the lithium iron phosphate battery, the other ends of the electric wires are fixedly provided with plugs, and the plugs are connected with the equipment shell. And a storage device for preventing a wire of the battery from being pulled apart is mounted on the equipment shell. After the battery is limited through the connecting device, the inserting block is moved to move out of the inserting groove to enter the first limiting groove, so that the L-shaped rotating plate can rotate, the L-shaped rotating plate is rotated to open the groove to expose an internal interface, a wire is wound on the wire winding rod to be stored, and then a plug is connected with the interface. The L-shaped rotating plate is rotated to reset, and the top end of the winding rod is blocked, so that the electric wire is prevented from falling off from the winding rod, and the situation that the electric wire is pulled apart is also avoided while the battery is conveniently connected.

The utility model discloses a smoke environment sudden early warning device which comprises a smoke detection port and a connecting flange, one side of the connecting flange extends out of a detection sampling pipe, the detection sampling pipe is inserted into the smoke detection port, and one side of the detection sampling pipe is provided with an active sampling detection structure; the utility model relates to the technical field of flue gas early warning devices, and in the flue gas environment sudden early warning device, a sampling detection mode is adopted to carry out flue gas environment monitoring, then a detection bypass is arranged on one side of a detection sampling pipe in a communicated mode, and a detection air pump on the detection bypass can be used for controlling the detection bypass to be opened. According to the flue gas detection device, the flue gas is actively extracted from the flue gas treatment pipeline, when the pressure in the flue gas treatment pipeline is reduced, flue gas detection can be carried out in an active gas inlet mode, then an alarm module on the flue gas sensor can be used for giving out an under-pressure alarm, and flue gas leakage is avoided.

The application discloses a substation pressure plate potential detection method and device, an intelligent voltage meter and a storage medium. The method comprises the following steps: in response to a first voice instruction, determining the identification information corresponding to the pressure plate to be measured, wherein the first voice instruction is triggered when a target button in the intelligent voltage meter is pressed and then lifted; determining the preset voltage value corresponding to the upper and lower terminals of the pressure plate to be measured according to the identification information corresponding to the pressure plate to be measured; acquiring the actual voltage value corresponding to the upper and lower terminals of the pressure plate to be measured, and comparing the actual voltage value with the preset voltage value; and in the case that the difference between the actual voltage value and the preset voltage value exceeds a preset proportion threshold, sending voltage alarm information. The application solves the technical problem of low substation pressure plate potential detection efficiency caused by the fact that in the related art, when the pressure plate is detected, the voltage value needs to be manually compared with the table and the standard value every time, resulting in low substation pressure plate potential detection efficiency.

The invention provides an equivalent testing device, method and equipment for a Hall propulsion load of a satellite. The equivalent testing device mainly comprises a thruster equivalent module, a storage and supply equivalent module, a high-voltage switching module and an equipment monitoring method. The thruster equivalent module is used for simulating a Hall thruster unit and realizing the load characteristics of the whole satellite under various working conditions under normal temperature and normal pressure; the storage and supply equivalent module is used for simulating a propulsion control unit load and mainly comprises control signal conditioning and state acquisition of a self-locking valve, an electromagnetic valve and a pressure sensor; the high-voltage switching module is used for connecting a load simulation cabinet cable and a satellite end cable, and a high-voltage alarm sub-module and a storage and supply self-checking sub-module are designed at the same time. The equipment monitoring method is used for collecting equipment state parameters and receiving a control remote instruction. The equipment is used for checking whether the function and the performance of the satellite Hall propulsion system are normal or not, the compatibility and the expansibility are high, and the equivalent requirements of different satellite Hall propulsion systems are met by adopting universal and modular design.

A dual differential contactless current sensor uses a pair of magnetic sensors placed adjacent to a conductor, such as a metallic trace on a printed circuit board, which is conducting electrical current. The ability to detect and measure a tampering magnetic field in such a sensor is provided by a circuit that sums the outputs of the pair of magnetic sensors. The circuit can output an alarm signal, such as a programmable one-bit alarm that indicates when the external magnetic field exceeds a programmed threshold, or an analog voltage proportional to the external field. The alarm signal can be polled by additional circuitry that indicates to the stakeholders that a party is attempting to alter the power measurement.

The invention relates to the technical field of battery monitoring, in particular to a battery low-voltage monitoring method and a battery low-voltage monitoring system using the same, and the method comprises the steps: building a battery equivalent circuit model through a Thevenin first-order RC model, calculating the initial state load voltage of equipment, obtaining three load voltages at different times after a load is started, and determining a stable load voltage; and calculating the voltage of the battery under the first-stage and second-stage fixed resistance loads, and determining the resistance value and the open-circuit voltage of the battery according to the voltage. The maximum working load of the equipment is estimated, the final output voltage under the maximum working load is calculated by combining the battery parameters, and a low-voltage alarm signal is sent out according to the final output voltage and the preset minimum working voltage. The battery voltage can be accurately monitored, the defects of a traditional method are avoided, the equipment reliability is improved, and the service life is prolonged.

The invention discloses a battery water inflow detection control method, a memory and a processor. The battery water inflow detection control method comprises the following steps: detecting whether the insulation resistance to ground of a battery is abnormal or not; detecting whether the voltage of the battery is abnormal; detecting whether the temperature of the battery is abnormal; carrying out weighted fusion calculation according to at least two of the ground insulation resistance alarm signal Dins, the voltage alarm signal Dvol and the temperature alarm signal Dtemp to obtain the water inflow probability of the battery; and when the calculated water inflow probability of the battery is within the water inflow threshold range, judging that water enters the battery and giving a water inflow alarm. Therefore, at least two of the insulation resistance to ground, the voltage and the temperature of the battery are used as factors for judging whether water enters the battery or not, so that false alarm of water entering of the battery caused by sensor failure or aging of a single factor is effectively avoided through multi-dimensional information fusion, and problems can be found in the early stage of water entering; and thermal runaway and battery pack fire are avoided.

A volt pen 1 having a fuse holder claw clamp 4 attached to the outer surface of the pen’s body 2 and a fuse pry tool 6 which may be fixed to the end of removable battery cap 12 or the end of a rotatin

The invention relates to the technical field of millimeter wave radar power supply and power consumption detection, in particular to a low-cost millimeter wave radar power supply system electric quantity detection method. Filtering the battery voltage signal and realizing stable sampling; establishing a mapping model of voltage and electric quantity and performing dynamic judgment; according to the electric quantity grade, driving an indicating lamp to realize visual display and provide an undervoltage alarm; and the average energy consumption is reduced through a low-power-consumption detection mode. According to the method, an analog-to-digital conversion channel of a single-chip microcomputer is used for obtaining battery voltage after voltage division, and stable input is obtained by combining hardware filtering and a mode of removing abnormal values through multiple times of sampling; when the electric quantity is in different grades, the indicating lamp outputs according to different preset stroboscopic strategies, and the stroboscopic frequency corresponding to the low electric quantity grade is higher than the medium electric quantity grade; and when the under-voltage threshold is triggered, a control signal is output to link energy-saving or shutdown protection, so that the cost, the stability and the safety are considered.

The invention discloses a battery alarm method, equipment and device, and the method comprises the steps: firstly obtaining the current battery monitoring data of a target battery pack, the current battery monitoring data comprises the battery pack voltage, the battery pack current, and the single voltage of each single battery, and then obtaining the battery alarm data of the target battery pack based on the battery pack current and the single average voltage; the method comprises the steps of determining a battery state of a target battery pack, then determining a voltage alarm threshold value corresponding to the battery state based on a preset corresponding relation, finally comparing target monitoring data with the voltage alarm threshold value, and giving an alarm according to the comparison, and the target monitoring data comprises a battery pack voltage or a target monomer voltage. The voltage alarm threshold value is determined based on the battery state, that is, different battery states correspond to different voltage alarm threshold values, and different voltage alarm threshold values are adopted for alarming under different battery states, so that the alarm accuracy can be improved, the service life of the battery can be prolonged, and the safety of the battery can be improved.

1. Name of the design product: current limiting module. 2. Use of the design product: to limit the current when the battery triggers over-voltage alarm or charging over-current to protect the battery. 3. Design points of the design product: in shape. 4. Picture or photo that best shows the design points: perspective view 1.

The invention discloses a line detection system, an electronic device and a method, and relates to the field of electronic circuits, a power supply assembly is configured to output a preset power supply voltage, and a main detection assembly comprises a first detection circuit and a second detection circuit. The first detection circuit is configured to obtain a first detection result according to the first digital voltage obtained in the first detection circuit, and the second detection circuit is configured to obtain a second detection result according to the second digital voltage obtained in the second detection circuit; the input end of the recheck supplementary circuit is electrically connected with the output end of the power supply assembly, and the recheck supplementary circuit is configured to determine a fault line according to the first detection result, the second detection result and a third detection result in the recheck supplementary circuit when the comparison results of the first detection result and the second detection result are different. According to the invention, the problems of low voltage alarm detection reliability, weak anti-interference capability and single alarm mechanism in the prior art are solved, and redundancy detection and accurate judgment of voltage alarm are realized through three independent detection lines and an intelligent cooperative judgment mechanism.

The utility model discloses a voltage monitoring alarm circuit of an atmospheric transmissometer transmitter, which comprises a voltage dividing unit, a voltage stabilizing and current limiting unit, a filtering unit, a chip NE555, an auxiliary adjusting unit, an alarm unit and a protection unit, the other end of the voltage dividing unit is connected with one end of the voltage stabilizing and current limiting unit, the other end of the voltage stabilizing and current limiting unit is respectively connected with a THR pin end and a TRI pin end of the chip NE555, one end of the auxiliary adjusting unit is respectively connected with the other end of the voltage stabilizing and current limiting unit and the TRI pin end of the chip NE555, one end of the alarm unit is connected with an OUT pin end of the chip NE555, and the other end of the alarm unit is connected with an OUT pin end of the chip NE555. One end of the filtering unit is connected with the CON pin end of the chip NE555; when the voltage of the monitored end of the atmospheric transmissometer is monitored to be lower than the voltage alarm threshold value, the chip NE555 controls the alarm unit to give an alarm.

The invention provides a high-pressure micro-fog main machine, and relates to the technical field of humidification. The high-pressure micro-fog main machine comprises a main machine box body; a water inlet pipe, a water inlet electromagnetic valve, a pressure switch and a pressure gauge which are connected in sequence are arranged in the host box body; a control system board is also arranged in the host box body; a terminal, a power switch and a controller which are electrically connected are arranged in the control system board; the control system board is electrically connected with the water inlet electromagnetic valve, the pressure switch and the pressure gauge. A touch screen is arranged on the surface of the mainframe box body, and the touch screen is electrically connected with the control system board. High-voltage alarm information, low-voltage alarm information and maintenance early warning information can be displayed, the host is prevented from being damaged, and the service life of the host is prolonged; the motor current, the motor frequency, the output voltage and the motor rotating speed can be displayed, and the real-time running state of the motor can be checked conveniently.

The invention provides a variable pitch backup power supply system of a wind turbine generator and the wind turbine generator. A super capacitor assembly and a fault energy release assembly are electrically connected and in signal communication with a charger assembly through a primary power cable and a secondary signal cable; the super capacitor assembly is formed by connecting a plurality of super capacitors in series, each capacitor in the module is provided with a voltage-sharing circuit, and the super capacitor assembly is integrated with an over-temperature alarm loop and an over-voltage alarm loop; the charger assembly primary loop converts external input alternating current into direct current meeting the charging requirement of the super-capacitor assembly, and the charger assembly secondary loop is integrated with a single-chip microcomputer, collects system parameters and calculates the state of the super-capacitor. A high-power resistor of the fault energy release assembly is connected with the super capacitor assembly through a circuit breaker and a contactor in sequence to form an energy release loop; the charger assembly controls on-off of a contactor coil through the digital quantity output signal so as to control opening and closing of an energy release loop. The whole system can instantly provide sufficient electric energy for the variable pitch driver.

The invention discloses a power distribution network single-phase earth fault positioning and protection method and system, and the method comprises the steps: collecting the zero-sequence voltage and three-phase current traveling waves of each power distribution switch through a power distribution terminal, and transmitting zero-sequence voltage alarm information when determining that a power distribution line has a single-phase earth fault according to the zero-sequence voltage, the wave head moment of the three-phase current traveling wave is extracted as a fault feature; and the power distribution main station determines target power distribution switches at the two ends of the fault according to the line topology of the power distribution line, the zero-sequence voltage alarm information and the fault characteristics, controls the target power distribution switches to be switched off and controls the corresponding interconnection switches to be switched on so as to isolate the fault. According to the method, the single-phase earth fault in the power distribution network is quickly and reliably diagnosed only by the zero-sequence voltage and the high-frequency current traveling wave, fault isolation and self-healing are automatically carried out, the fault influence is reduced, external interference on diagnosis is small, the fault-tolerant rate is high, equipment transformation is not needed, and the method is easy to implement.

The utility model relates to the technical field of high-voltage alarm, in particular to an alarm system for a static rod, which comprises a power supply device, an electronic rod, a detection device and an alarm device, a first power supply component is mounted at one end of the power supply device far away from the electronic rod, and a first connector is arranged at one end of the electronic rod close to the power supply device. A second connector is arranged at one end, far away from the first connector, of the electronic rod, and a rotatable sensitive adjusting part is arranged on the detection device. And the detection device is connected with the electronic rod through the second cable, so that working parameters such as voltage of the electronic rod can be accurately obtained in real time. And the detection threshold value can be flexibly adjusted by the rotatable sensitive adjusting piece according to actual requirements. And when the voltage of the electronic rod is lower than an adjustment value, the detection device can quickly transmit a signal to the alarm device through the third cable, so that quick fault early warning is realized, and production accidents or product quality problems caused by faults of the electrostatic rod are reduced.

The present disclosure relates to the field of power grid monitoring, and particularly relates to a power grid equipment voltage anomaly feature extraction method and system based on a factor analysis method, the method comprising the following steps: obtaining a power grid equipment section bus three-phase voltage value and an alarm signal; obtaining a section bus three-phase voltage value based on normal distribution statistics of random components in historical power grid equipment standardized samples to obtain a sample random component fluctuation lower limit and a fluctuation upper limit, performing factor analysis extraction to obtain a random component, and judging whether the random component exceeds the fluctuation lower limit and the fluctuation upper limit; if the fluctuation lower limit and the fluctuation upper limit are exceeded, then combining the alarm signal to perform voltage anomaly research and judgment to achieve power grid equipment voltage anomaly feature extraction. The present disclosure can perform voltage recovery research and judgment, voltage anomaly research and judgment, and whether it is a non-shielded event according to the bus three-phase voltage of the power grid equipment combined with the voltage alarm signal data.

The invention provides a battery state control method and a battery management system, and the method comprises the steps: monitoring the charging and discharging parameters of a battery, and judging the state of the battery; when the battery triggers a charging forbidding alarm or a discharging forbidding alarm, performing abnormal state marking on the battery according to the type of the alarm; after the abnormal state mark of the battery is eliminated, the state of the battery is recovered to be a normal state, and the step of marking the abnormal state of the battery according to the type of the alarm comprises the substeps that when the battery triggers the voltage alarm, the battery is marked to be in a full-charge state or an emptying state according to the type of the voltage alarm; the full state and the emptying state are eliminated after the marked preset time, so that the voltage alarm state of the battery is maintained for the preset time. The state of the battery system is managed by introducing the full-charge state, the emptying state and the locking current alarm state, so that the repeated conversion of the system state in a short time is effectively prevented, and the service life of the battery is ensured.

The invention belongs to the field of high-voltage protection detection, and mainly relates to a verification device of high-voltage alarm equipment, which is characterized by comprising a high-voltage field module used for simulating a real electric field environment; the support device is not in contact with the high-voltage field module, the end of the support device extends into the high-voltage field module, and the support device is used for placing the alarm equipment to be verified; the electric field sensing module is installed on the supporting device, and the electric field sensing module and the supporting device extend into the electric field center position of the high-voltage field module; and the control module is electrically connected with the electric field sensing module and is used for controlling the output and change of the high voltage in the high-voltage field module. According to the invention, a real electric field environment is simulated from a three-dimensional direction, a plurality of parameters are checked, high-voltage alarm devices of different specifications are calibrated in a unified manner, and data are accurate and reliable; the distance between the device and a high-voltage field is adjusted through the far-end support, safety protection is achieved, facilities can be remotely controlled, and the detection process is safe and reliable.

The utility model discloses a low-voltage alarm switching power supply control circuit, which comprises a filter rectifier module, a voltage transformation module, a filter output module, a battery power supply module and a low-voltage alarm module, the input end of the filter rectifier module is connected with a mains alternating-current power supply; the input end of the voltage transformation module is connected with the output end of the filter rectifier module; the input end of the filtering output module is connected with the output end of the voltage transformation module; the battery power supply module is connected with the filtering output module and the low-voltage alarm module. The battery power supply module is used for storing electric energy, and is used for discharging when the mains supply AC power supply is powered off. And a voltage stabilizing diode ZD1 in the low-voltage alarm module changes the on-off state of the voltage stabilizing diode ZD1 by detecting the output voltage of the battery power supply module, and controls the on-off states of the optical coupler U2 and the triode Q1 by utilizing the on-off state of the voltage stabilizing diode ZD1, thereby controlling the light emitting diode LED4 to be turned on or turned off. And when the voltage output by the battery power supply module is lower than a preset value, the LED lights up to prompt a user that the voltage of the battery power supply module is reduced.

The utility model discloses an insulating shoe with step voltage alarm, which comprises a shoe body, an early warning circuit is arranged in the shoe body, the front end and the rear end of the bottom of the shoe body are respectively provided with a mounting groove, each mounting groove is provided with a grounding electrode slice, the grounding electrode slices at the front end and the rear end and the early warning circuit form a grounding loop through the mounting grooves, and the grounding loop is connected with the early warning circuit. And the early warning circuit is used for carrying out step voltage early warning prompt on an area where a person wearing the insulated shoe is located so as to provide step voltage risk prompt for the worker.

The invention discloses a power load under-voltage short-circuit double-alarm protection circuit, and relates to the technical field of power protection, and the circuit comprises a plurality of modules which are used for carrying out the voltage sampling and voltage signal processing of AC electric energy, obtaining a sampling voltage signal, carrying out the 180-degree phase shift processing and superposition processing of the sampling voltage signal, and obtaining a voltage signal; performing absolute value processing on the second potential signal to obtain a third potential signal, outputting a control signal when the first potential signal is greater than a preset fault threshold value or the third potential signal is greater than a preset fault threshold value, and outputting a control signal when the control signal is received. And the control module is used for controlling the power supply control module to stop providing alternating-current electric energy for the power load module, continuously performing short-circuit alarm when receiving the first potential signal and the control signal at the same time, and continuously performing under-voltage alarm when receiving the third potential signal and the control signal at the same time. The size of the protection circuit can be reduced.

The utility model relates to the technical field of lithium battery testing, in particular to a high-voltage alarm protection device for charging and discharging testing equipment. The execution unit, the control unit and the resistor are arranged in the equipment shell, the control panel is in mutual electric signal connection with the execution unit and the control unit, a wiring terminal row group is further arranged on the rear side of the equipment shell, and the wiring terminal row group is used for connecting a power line of the charging and discharging test equipment with a battery pack. And a driving switch and an emergency stop switch are arranged on the control panel. According to the technical scheme of the utility model, the novel control circuit system is arranged, so that the influence of a high-voltage arc discharge phenomenon caused by instantaneous high voltage when the charging and discharging test equipment is connected with the battery pack on test operators and tested battery pack products can be avoided; the safety of an operation process is improved, the operation intensity of personnel operation is reduced, and faults of charging and discharging test equipment are reduced; the whole structure is simple, safety is high, and operation is convenient.

The invention discloses a multistage discharge control system and control method for an energy storage lithium battery in the technical field of energy storage charge and discharge, and the method comprises the steps: collecting the voltage and temperature of a single cell in a battery cluster in real time, and obtaining the residual SOC of the battery cluster; calculating a discharge dynamic step number; calculating a discharge single-step monomer voltage variation, and performing correction based on the multi-stage under-voltage alarm threshold and the temperature-SOC cooperative compensation model to obtain a compensated discharge single-step monomer voltage variation; when the minimum voltage value of the single battery cells in the battery cluster reaches a preset alarm condition, executing a multi-stage dynamic step power reduction discharge process; after all dynamic step power reduction is completed, entering a constant-voltage current-limiting discharge stage; when a discharge stop condition is satisfied, the discharge process is terminated. According to the invention, the problem of rapid voltage drop of the discharge end cell and the problem of early protection of discharge end monomer under-voltage caused by chemical properties of the battery are solved, and efficient capacity utilization of the discharge system and benefit maximization of the energy storage system are realized.

An intelligent induced voltage alarm device comprises a power frequency electric field sensor, a signal processing unit, a power supply unit, a sound-light alarm unit and a communication unit. The device is worn on a worker; the signal processing unit is connected with the power frequency electric field sensor and the sound-light alarm unit, field operation voltage parameters are stored in the signal processing unit, the induced voltage sensed by a human body at the moment is judged according to the electric field intensity collected by the power frequency electric field sensor, and when the induced voltage is larger than the voltage parameters built in a chip, the alarm device gives an alarm. Workers are reminded to pay attention to safety, and electric shock is prevented; the device automatically gives an alarm when inducting that the voltage is higher than the induced voltage which can be borne by a human body, so that a safety prompt function is provided for people.