86results about How to "Avoid current shock" patented technology

The invention relates to an LED power circuit comprising a bridge rectifier circuit, a driving circuit, a transformation rectification circuit, a switch circuit, a feedback circuit and an LED light-source circuit. The bridge rectifier circuit is used for rectifying AC power input by commercial power; the driving circuit is used for keeping the LED power circuit connecting to a traditional dimmer to work normally; the transformation rectification circuit is used for providing working current for the LED power circuit under the control of the switch circuit; and the feedback circuit feeds back a working voltage to the switch circuit from the transformation rectification circuit.

The invention provides a skylight controlling unit of a vehicle belonging to the technology and electronics field. The invention resolves the problems of the current vehicle skylight such as single function, poor controlling precision, etc. while controlling a skylight. The skylight controlling unit of vehicle includes a microcontroller. The microcontroller is connected with a power supply for supplying the whole unit, bottons for operation and a start switch for sending opening and closing signals; besides, a drive circuit is connected with the microcontroller, the output end of the drive circuit is connected with a motor, and the motor is also connected with a sensor for testing the motor running state, the output end of the sensor is connected to the microcontroller. The skylight controlling unit of the vehicle uses double control way of Hawl pulse counting and the current test of the motor to control, hereby is characterized by complete functions, high controlling precision and reliable characteristics, long service life of the motor.

The application discloses a precharging circuit and a photovoltaic inverter. The precharging circuit comprises an AC power supply, a rectification half bridge, an auxiliary charging capacitor, a current limiting apparatus and a controllable switch, and is in connection with a target charging capacitor to form a voltage-multiplying rectification circuit, wherein the DC side of the rectification half bridge is in parallel connection with the target charging capacitor, and the AC side of the rectification half bridge is in connection with one end of the AC power supply; one end of the auxiliary charging capacitor is in connection with any end of the target charging capacitor, and the other end of the auxiliary charging capacitor is in connection with the other end of the AC power supply; the current limiting apparatus is in series connection with each charging path of the precharging circuit. The controllable switch is in series connection with each charging path of the precharging circuit, so as to solve the problem of a low DC bus precharging voltage, thereby avoiding generating current impact when the photovoltaic inverter is in connection with a photovoltaic cell or performs parallel connection.

The invention provides an intelligent switch which comprises a load switch, an operating mechanism, a position state indicator, an upper disconnecting switch, a lower disconnecting switch, a current transformer, a first potential transformer, a second potential transformer, an electronic switch, a charging module, a battery and an intelligent device, wherein the load switch is connected on a main circuit and located between the upper disconnecting switch and the lower disconnecting switch; the electronic switch is connected with the load switch in parallel; the current transformer is sleeved on a branch circuit where the load switch is located; and the load switch and the electronic switch are connected in parallel. The first potential transformer and the second potential transformer are respectively connected with the charging module and can charge the battery from two sides; the intelligent device is connected to the current transformer and the charging module, and the battery can provide direct current supply for the intelligent device and the operating mechanism; the battery is connected with the charging module; the operating mechanism is connected with the load switch; and the indicator is connected with the operating mechanism. The invention also provides a control method of the intelligent switch.

The invention discloses a method for controlling the torque change rate of a permanent magnet synchronous motor. The method comprises the following steps of a detecting step: detecting the three-phase current and rotary speed of an armature of the motor during operation in real time; a converting step: converting the detected armature three-phase current into a motor alternating-direct axle current based on Clark-Park conversion and calculating a corresponding alternating-direct axle voltage; a torque adjusting step: calculating a modulation factor Mindex based on the alternating-direct current and voltage obtained in the conversion step and adjusting the outputted torques at different torque change rates in a sectional mode according to the range of the modulation factor Mindex value. According to the method and device for controlling the torque change rate of the permanent magnet synchronous motor, a relatively faster torque responding speed is adopted during the control of the maximum torque current ratio, and a relatively smoother torque responding speed is adopted during flux weakening control. The motor is stable in torque outputting, strong in antijamming capacity and fast in accelerated speed and the system is high in brake efficiency. Current impact of the system during high speed can be effectively prevented and the motor in flux weakening control is prevented from being out of control.

A precharge soft starting circuit for a three-phase voltage type bi-directional PWM current transformer comprises a first contactor K1, a three-phase diode rectifier bridge TM, a BUCK-BOOST circuit, a second contactor K2 and a DSP, wherein a three-phase alternating voltage source is connected with the alternating-current side of the three-phase diode rectifier bridge TM through the first contactor, the direct-current side of the three-phase diode rectifier bridge TM is connected with the BUCK-BOOST circuit, the BUCK-BOOST circuit is connected with the second contactor K2, the second contactor K2 is connected with the two sides of a direct-current end bus capacitor, and the first contactor K1, the controlled end of the BUCK-BOOST circuit and the second contactor K2 are all connected with the control end of the DSP. Current surge in the starting process is effectively avoided, so that service life is prolonged.

A self-starting control apparatus for intelligent electric energy router DC unit and a self-starting method are disclosed. An input side H-bridge control circuit takes electricity from an input side power supply through a first draw-out power coil, and an output side H-bridge control circuit takes electricity from an output side DC capacitor through a second draw-out power coil. The convertor self-starting method comprises the steps in which an output side H-bridge switch is locked, an output side H-bridge is equivalent to a uncontrolled rectifier bridge and the switching state of an input side H-bridge is adjusted so that the duty ratio D of an AC square wave outputted by the input side H-bridge gradually rises from 0 to 0.5. When the voltage of the output side DC capacitor is stabilized, the output side H-bridge switch is changed into a controlled state.

The invention relates to a control method of a variable frequency lift pump based on liquid level adjustment. The control method comprises the following steps of: switching protection of a water pump during frequency conversion: firstly, forcibly lifting the frequency of a frequency converter to a set frequency value before switching the power frequency of the lift pump into a variable frequency; and variable frequency adjustment method of the lift pump for liquid level feedback control: adopting a constant water level PID variable frequency adjustment mode of absorption well water level tracking for the variable frequency adjustment control of the lift pump. Compared with the prior art, the invention has the advantages of solving the problem of current impact on the frequency converter due to load current break during the switching of the variable frequency pump, so that the service life of the frequency converter is greatly prolonged; meanwhile, the phenomenon of frequency converter damages caused by too great impact current is also avoided. The method has practicability in the aspect of switching control of a plurality of variable frequency pumps.

The invention relates to an intellectual full bridge soft switching potentiostat, pertaining to the technical field of corrosion and protection. The input end of an AC rectification circuit is connected with an AC input power and the output end thereof is communicated with an AC filter circuit; the output end of the AC filter circuit, a soft switching circuit, a pulse phase shifting control drive circuit and the input port of a high frequency transformer are respectively electrically communicated with a full bridge converter schematically; the output end of the high frequency transformer is in butt-joint with the input end of a high frequency rectification filter circuit, and the output end of the high frequency rectification filter circuit outputs DC power; the pulse phase shifting control drive circuit is composed of a reference electrode separation amplification circuit, a phase shift controller, a switch valve drive circuit, a signal comparison control circuit, a liquid-crystal display and a keying circuit as well as a monolithic system which are communicated electrically. The whole machine is characterized by novel structure and principle, simple principle, small product volume and light weight, low preparation cost and convenient application and operation and energy saving.

The invention provides a circuit for preventing power up instantaneous shock in inverter air conditioner which includes a positive temperature coefficient thermistor series connected with AC electrical source front line in air conditioner system, a power relay switch parallel connected with two sides of the positive temperature coefficient thermistor, the power relay coil and a controllable switch device are series connected between electrical source and ground electrode, the controllable switch device control end is connected with one electrical source in air conditioner system. The circuit provided by the invention can prevent current shock in power up instantaneous, and can conquer disadvantage of poor anti-interference performance in present device because of impervious for main control singlechip reduction, and protect air conditioner system normal working more efficiently.

The invention relates to a control device of a starting and generating integrated system used for a small-sized internal-combustion engine. A starting circuit and a generating circuit mainly comprise a starting board, two relays, two field-effect tubes and a rectification voltage-stabilizing charging circuit. The switching moment of starting and generating is determined by utilizing the minimum stable idle speed after an engine is started as the standard, and the starting state is switched to the generating state when the speed of the engine reaches or is higher than the stable idle speed; the generating state is switched to the starting state when the speed of the engine is lower than the stable idle speed. The switching of the starting circuit and the generating circuit is controlled by a singlechip through the relays and an electronic switch. The invention has the characteristics of simple circuit design and reliable switching control and can effectively avoid current impact caused in switching the starting state and the generating state.

The invention discloses a method and a device for tracking motor speed by a frequency changer and the frequency changer. The method comprises the following steps: step one, obtaining the initial tracking frequency f0 and tracking direction of speed tracking; step two, carrying out demagnetizing treatment on a motor, and blocking PWM output when the frequency changer is in a demagnetizing period; step three, applying a rotating voltage on the motor, and maintaining for a period of time; step four, in the period of speed tracking, using the initial tracking frequency f0 as tracking frequency, outputting an output voltage according to a preset speed tracking V / F curve according to the tracking frequency, continuously changing the tracking frequency and output voltage of the frequency changer,then detecting the stator current of the frequency changer, and judging whether the current active component direction of the stator current changes, if the current active component direction changes, obtaining the actual operating speed of the motor according to the tracking frequency of changing switching points so that the output voltage is increased to a normally controlled output voltage value. The method is high in detection efficiency and more accurate and stable. The device and the frequency changer comprise the method.

The invention relates to a light-adjustable light-emitting diode (LED) drive circuit. The light-adjustable LED drive circuit is strong in anti-electromagnetic interference, high in power factor and high in reliability. The light-adjustable LED drive circuit comprises an anti-electromagnetic interference unit used for filtering external electromagnetic interference, a power factor correction unit used for improving the power factors of a power supply, a bridge rectifier circuit used for converting alternating current electric energy into direct current electric energy, a light modulator used for modulating voltage input into a voltage transformation rectifying circuit, a drive unit used for supplying electric energy to the light modulator, a voltage transformation rectifying circuit providing work current for an an LED light-source unit, a feedback circuit used for feeding back the work voltage of the voltage transformation rectifying circuit to a switch control circuit, the switch control circuit used for controlling output current of the voltage transformation rectifying circuit, and the LED light-source unit.

The invention relates to a three-wire high power LED drive which is mainly used for driving a high power LED. The three-wire high power LED drive comprises an LED drive and a high power LED load and is characterized in that the LED drive is provided with three output wires which are an output anode, an output cathode and a signal control wire respectively. The high power LED load is connected between the output anode and the output cathode. S1 is a control switch. One end of the S1 is connected with the output anode, and the other end thereof is connected with the signal control wire. The signal control wire is connected with a diode anode in an LED drive opto-coupler U2 by a current-limiting resistor R10. The control switch S1, the signal control wire and the current-limiting resistor R10 form a low voltage control circuit together. The three-wire high power LED drive can effectively avoid the problem of current surge when the control switch is closed.

The invention relates to a double-input power source. The double-input power source comprises a main power input end for input of main power input, a backup power input end for backup power input, a soft starting circuit for performing current limiting processing on the input current of the main power input end and the input current of the backup power input end, and a bus capacitor for stabilizing the output voltage of the double-input power source, wherein the soft starting circuit is respectively connected with the main power input end and the backup power input end. The invention also relates to a network device. The two paths of power input of the double-input power source and the network device only employ one soft starting circuit so that the double-input power source has a small size, the manufacturing cost is low, and current impact when a backup power source is started can be prevented.

The invention provides an initial voltage adaptive method for a constant-voltage dimming power supply. The initial voltage adaptive method is characterized by comprising the steps of controlling the output voltage to be boosted slowly when the dimming power supply is started; monitoring the operating current of an LED through a current detection circuit connected with the to-be-driven LED in series; when the LED generates the operating current, processing the monitored operating current of the LED through a current processing circuit, wherein the operating voltage is the initial voltage of the LED, and under the initial voltage, the minimum LED dimming luminance is recorded and defined by external hardware or software; and the maximum LED dimming luminance of the dimming power supply is achieved at a rated constant voltage point of the constant-voltage dimming power supply. By adoption of the method, different types of LED lamp beads or modules can be adapted, so that the dimming power supply can realize changes from the minimum LED dimming to the maximum LED dimming directly, the adaptability of the power supply is greatly improved, and the dimming range of the LED is expanded; and therefore, the technical problems of decreased dimming range and matching failure with a driving power supply caused by the starting voltage differences of the LED lamp beads of the LED dimming power supply are solved.

The invention discloses a novel charging control method based on lithium battery characteristics. The method comprises the steps of: S1, detecting that a lithium battery needs to be charged; S2, according to a preset pre-charging current, carrying out stepped pre-charging on the lithium battery; S3, after completing pre-charging, carrying out constant-current charging on the lithium battery according to a preset constant-current charging current; and S4, after completing constant-current charging, carrying out constant-voltage charging on the lithium battery. By adopting the novel charging control method, the technical problem of overcharge in the charging starting process is solved.

The invention discloses a pre-charging circuit which comprises a first switch, a second switch, a diode, a first current limiting device, a capacitor and an inversion unit. One end of the pre-chargingcircuit is connected with a power grid, after the first current limiting device, the first switch and the diode are connected in series, one end of the series connected structure is connected with one end of the capacitor, and the other end is connected with a first-phase alternating current of the power grid. The other end of the capacitor is connected to a second-phase alternating current of the power grid sequentially through the inversion unit and the second switch, after the first switch and the second switch are closed, the current outputted by the power grid passes through a closed loop formed by the first current limiting device, the first switch, the diode, the capacitor, the inversion unit and the second switch to charge the capacitor. The circuit for pre-charging the bus capacitor is provided, is simple in, is changed rarely on the basis of an existing inverter system, and saves the cost.

A control system applied to a brick machine, including an MPI bus and a main control module and a control panel connected to the MPI bus, and also includes a variable vibration module for controlling a vibration device, an anti-jamming module for receiving action feedback signals, and The output surge module used to issue action commands, the variable vibration module, the anti-interference module and the output surge module are respectively connected to the main control module. The variable vibration module includes a power supply, two motors, a frequency converter, and is connected between the power supply and the frequency converter. A contactor, a braking unit electrically connected to the frequency converter, two air switches and two air switch contacts, the two air switches are respectively connected between the frequency converter and the two motors, and the two air switch contacts are connected in series and connected to the frequency converter. The main control module is used for program control, and the anti-jamming module and output surge module are used for signal transmission control with each part of the brick machine, which can realize the automatic production control of the brick machine; the variable vibration module has a soft start function, which can realize the two motors. Synchronous work.

The invention relates to an elevator safety protection control method, device and equipment. The elevator safety protection control method can comprises the following steps that when an elevator performs star-sealing braking, first star-sealing protection signals and second star-sealing protection signals are generated; the first star-sealing protection signals are transmitted to all upper bridgearm switch pipes of an inverter correspondingly; the first star-sealing protection signals are used for indicating all the upper bridge arm switch pipes to cut off a power-supply power source of a motor; the second star-sealing protection signals are transmitted to all lower bridge arm switch pipes of the inverter according to a predetermined sequence; the predetermined sequence is a phase coincidence sequence of the current phase of the motor and the magnetic-pole phases of the lower bridge arm switch pipes during closing; and the second star-sealing protection signals are used for indicatingall the lower bridge arm switch pipes to restrain the unbalanced electric current of the motor at the beginning of star sealing. By means of the elevator safety protection control method, cutting offthe power-supply power source of the motor can be realized, overlarge current shock at the beginning of star sealing is avoided at the same time, star-sealing braking is performed with maximum braking force, and the safety of the elevator is effectively improved.

The invention provides a pre-charging circuit, a control method thereof and a converter. The pre-charging circuit includes a first capacitor bank, a second capacitor bank, at least one pair of path switching circuits including a first path switching circuit and a second path switching circuit, and a charging power supply circuit. When the pre-charging voltages of the first capacitor bank and the second capacitor bank do not reach a predetermined value, each pair of path switching circuits are operated sequentially in each pre-charging cycle. The operations include the following steps that: within the first conduction time, a first path of the first path switching circuit and a second path of the second path switching circuit are conducted to charge the first capacitor bank through the charging power supply circuit; after the first conduction time, the first path and the second path are disconnected; and moreover, within the second conduction time, a third path of the first path switching circuit and a fourth path of the second path switching circuit are conducted to charge the second capacitor bank through the charging power supply circuit.

The invention discloses a slow start circuit and an optical module with the same. The slow start circuit provided with a power source input end and a load output end comprises a switch device and a switch voltage adjuster and current discharge channel connected therewith. The switch device is in series connection between the power source input end and the load output end. The switch voltage adjuster controls opening of the current discharge channel during disconnection of the power source input end so as to enable the load output end to discharge electricity, and controls closing of the current discharge channel during power-on of the power source input end. Due to arrangement of the current discharge channel in the slow start circuit, the load output end can discharge electricity by the current discharge channel through control of the switch voltage adjuster when the power source input end is disconnected, so that the switch device does not respond timely to be connected in the ephemeral power-on process, caused by mechanical dither, of the slow start circuit and the power source input end, power supply to the load output end is avoided, and further, current impact on a power source is avoided.

The invention discloses an energy storage system grid-connected and off-grid switching system and switching method. The system comprises a grid-connected and off-grid switching device STS and a bidirectional energy storage converter PCS, wherein the grid-connected and off-grid switching device STS comprises a controller, a thyristor SCR, a first-stage relay and a second-stage relay, a first-stage relay and a second-stage relay in the main circuit of the grid-connected and off-grid switching device STS are sequentially connected, the thyristor SCR is connected to the second-stage relay in parallel, and a controller in the control circuit of the grid-connected and off-grid switching device STS is connected with the two-stage relay and the thyristor SCR. According to the invention, the SCR is connected to the two ends of the relay in parallel, signals can be sent to the SCR and the relay at the same time when the relay is disconnected from the grid, and due to the fact that the semiconductor switch speed is high, the SCR can be switched on firstly, so that no voltage difference exists between the two sides of the relay when the relay acts, and arc discharge and relay adhesion cannot be caused when the relay is disconnected.

The invention provides a photovoltaic assembly with a lightning-protection device, comprising a discharge tube, wherein one end of the discharge tube is electrically connected with the output end of the photovoltaic assembly, and the other end of the discharge tube is connected to the ground. Thus the photovoltaic assembly can effectively prevent the damage of thunder and lightning. In the optimal scheme, the photovoltaic assembly also comprises a voltage dependent resistor, and the voltage dependent resistor is electrically connected between the discharge tube and the output end of the photovoltaic assembly and connected in series with the discharge tube. Thus the service life of the discharge tube and the voltage dependent resistor can be effectively prolonged.

The invention relates to an intermediate frequency inverter automatic welding machine special for a smoke exhauster hood. A plurality of welding spots can be automatically welded by one-time pressurizing; the whole machine adopts a single chip microcomputer to control each action; and an operation panel adopts a circular button switch which is intuitive and convenient to adjust. According to the intermediate frequency inverter automatic welding machine special for the smoke exhauster hood, the intermediate frequency inverter welding machine is adopted to convert an IGBT alternating current toa direct current, a resistance welding power source provides energy for welding, before welding, the welding machine absorbs energy from a power grid to charge a capacitor with a small current for a long time and store electricity, in the welding process, power supply of the power grid is stopped, thus current impact on the power grid like a power-frequency resistance welding machine is avoided, therefore, the requirement for the power supply capacity of the power grid can be reduced, in the welding process, discharge is rapid, the waveform is steep, the energy is concentrated, no alternatingcurrent zero crossing intermittent process exists, the welding thermal efficiency is high, adjustment and control are easy, thus structures with physical properties or thickness ratios which have great difference can be welded.

The invention mainly discloses a high-power motor frequency conversion switching system and a control method thereof. The system comprises an acquisition circuit unit, a judgment circuit unit, a control circuit unit, an execution circuit unit and an electric control loop unit. The acquisition circuit unit is connected with a judging circuit unit, and the judging circuit unit is connected with a control circuit unit and an execution circuit unit. The executing circuit unit is connected with the electric control loop unit; The electric control loop unit is connected with a motor; The collectingcircuit unit comprises a collecting signal module, a rectifying module, a power signal processing module and a comparison signal processing module. The judging circuit unit comprises an amplifying circuit module and a phase detecting circuit module. The patent of the invention effectively improves the success rate of switching, can quickly and accurately capture the phase synchronization, and thesystem is simple and efficient, the stability and the success rate of switching will increase after the system is simple, the system effectively reduces the cost, and can be mass produced and processed.

An embodiment of the invention provides a power conversion circuit, a control method of the power conversion circuit and a transformer, which are used for reducing the size of a device in the power conversion circuit and improving the reliability of a system. The power conversion circuit comprises at least one first power conversion unit connected to a first phase line in series, at least one second power conversion unit connected to a second phase line in series, at least one third power conversion unit connected to a third phase line in series, a plurality of first starting circuits connected to the first phase line in series, and a plurality of second starting circuits connected to the second phase line in series, wherein each first starting circuit comprises a first relay and a first resistor which are connected in parallel, and the first relay in each first starting circuit is sequentially closed after the power conversion circuit is powered on and is used for starting the power conversion circuit; and each second starting circuit comprises a second relay and a second resistor which are connected in parallel, and the second relay in each second starting circuit is sequentially closed after the power conversion circuit is powered on and is used for starting the power conversion circuit.

The invention proposes a DC output circuit and a charging pile. N DC output units are sequentially connected in series by a series assembly, first poles of the N DC output units are respectively connected to corresponding first branches, a backflow prevention device is correspondingly arranged on each first branch, and second poles of the N DC output units are respectively connected to corresponding second branches. A series state or a parallel state of each DC output unit is switched by the series assembly and a parallel assembly; and by arranging the backflow prevention device on each firstbranch adjacent to the first pole of each DC output unit, backflow of an output current of each DC output unit is prevented when parallel instantaneous moment is switched, and thus, the situation thatthe device is easily damaged by current impact generated by voltage different is prevented.