78results about How to "Realize short circuit protection" patented technology

The invention discloses a method and a device for short circuit protection of a half-bridge resonant converter. The method for the short circuit protection of the half-bridge resonant converter comprises the steps of detecting a secondary side current signal of the half-bridge resonant converter, and converting the detected secondary side current signal into a corresponding first sampling voltage signal; and judging whether wave chasing protection needs to be carried out according to the first sampling voltage signal, and when the wave chasing protection needs to be carried out, blockading a driving signal of the half-bridge resonant converter in a forcible mode in a preset period. The method for the short circuit protection of the half-bridge resonant converter is capable of carrying out the short circuit protection on the half-bridge resonant converter, and satisfying the requirement for increasing the power density of the half-bridge resonant converter at the same time.

The invention discloses a current monitoring circuit with the accurate current-limit function. The current monitoring circuit with the accurate current-limit function comprises an operational amplifier, wherein a forward input end and a reverse input end of the operational amplifier are respectively connected with a resistor in series, the resistors are symmetrical to each other, the reverse input end of the operational amplifier is connected to the output end of the operational amplifier in series through a resistor R1 and a capacitor C1, the symmetrical resistors which are connected with the operational amplifier in series are further in ground connection, an output filtering loop is formed by an inductor L1 and a capacitor CL, a load RL is connected to the capacitor CL in parallel, and is connected with a feedback resistor Rf in series, the feedback resistor Rf is connected to the forward input end of the operational amplifier am1 in series, and is used for carrying out sampling on current change signals of the output filtering loop, and the sampled current change signals are converted into voltage signals to be input into the forward input end of the operational amplifier. The current monitoring circuit with the accurate current-limit function directly detects output current signals, the output current signals are converted into the voltage signals through the resistors, and compared with reference voltage, the level of an enabling end can be reduced through output overturn of the operational amplifier, and short-circuit protection is achieved.

The invention provides an IGBT short circuit protection circuit and method, an IGBT driver and an IGBT circuit. The IGBT short circuit protection circuit comprises a drive current detection unit, used for detecting the drive current flowing through an IGBT gate; a comparison unit, used for comparing the drive current with reference current and outputting a comparison result; and a protection unit, used for determining whether to start short circuit protection of the IGBT according to the comparison result. According to the technical scheme, the drive current flowing through the IGBT is detected to control the self locking of the IGBT drive circuit, so as to improve the reliability of the short circuit protection of the IGBT.

The invention discloses a short-circuit protection method for buffer output of a DC/DC (Direct-Current/Direct-Current) power supply converter and a buffer output circuit of the power supply converter, wherein a short-circuit protection circuit is arranged between the output end of a DC/DC module power supply and a buffer circuit; when a load is short-circuited, the short-circuit protection circuit is triggered to be in a short-circuit working state to cause that the output end of the DC/DC module power supply is short-circuited; then, short-circuit protection in the DC/DC module power supply is triggered, so that voltage output to the buffer circuit by the DC/DC module power supply is in a safe state, therefore, the short-circuit protection of the buffer circuit is realized; when the converter is started and the output load is normal, the short-circuit protection circuit is in an open-circuit working state; and, besides having load interference resistance capability, the DC/DC power supply converter disclosed by the invention is capable of realizing short-circuit protection of the whole DC/DC power supply converter when the load is short-circuited, preventing a buffer MOS (Metal Oxide Semiconductor) transistor in the buffer circuit from being damaged, and reducing short-circuit power consumption of the converter at the same time.

The invention discloses a charger protection circuit which is connected between an anode output end of a charger and an AC/DC conversion controller. The charger protection circuit comprises a switch tube Q1, a voltage source VCC, a diode D4, a load R and a load R4, wherein the voltage source VCC and the anode of the diode D4 are electrically connected with a collector of the switch tube Q1 respectively, one end of the load R and one end of the load R4 are electrically connected with a base of the switch tube Q1 respectively, the other end of the load R4 and an emitter of the switch tube Q1 are grounded, the other end of the load R is used for connecting with the anode output end of the charger, and the cathode of the diode D4 is used for connecting with the AC/DC conversion controller of the charger. By adopting the technical scheme, the charger protection circuit not only realizes short circuit protection of the charger, but also effectively avoids damage to a power battery.

The invention discloses an operation method of a multistage oil-water separation tank of an intelligent pulse electrostatic coalescence electrode. The amount of high-water-content crude oil in an oil-water separation chamber is continuously increased, so that the liquid level continuously rises; the liquid level of the high-water-content crude oil sequentially enters a first-stage electrostatic coalescence oil-water separation area, a second-stage electrostatic coalescence oil-water separation area, a third-stage electrostatic coalescence oil-water separation area, a fourth-stage electrostaticcoalescence oil-water separation area and a fifth-stage electrostatic coalescence oil-water separation area upwards; the purpose of controlling the electric quantity of an electrostatic field in eacharea is achieved by adjusting the electric quantity on the first insulating electrode and the second insulating electrode through a controller, after water-containing crude oil enters the electrostatic field, water drops in the water-containing crude oil are polarized and deformed under the action of electrostatic field force, small water drops are coalesced into large water drops to settle downwards, and it is guaranteed that the water content of the separated crude oil is greatly reduced; the problems of low dehydration rate and high oil content in drained water of a secondary separator aresolved by adding the electrostatic fields, the dehydration efficiency is effectively improved, and the production cost is reduced.

The invention belongs to the technical field of power electronics, and particularly relates to a short-circuit protection device of a solid-state switch. The short-circuit protection device of the solid-state switch comprises a power device switch unit, an intelligent detection and protection unit and a buffer circuit unit, wherein the power device switch unit is connected to a main circuit system and is used for achieving on/off function of a main circuit; the intelligent detection and protection unit comprises a near-end short-circuit protection module and a remote-end short-circuit protection module and is used for sending out a shut-off signal to the power device switch unit when in a near-end short-circuit or a remote-end short-circuit; and the buffer circuit unit is connected to two ends of the power device switch unit and is used for absorbing over-voltages generated at two ends when the short-circuit is shut off and the power device switch unit is turned off. A corresponding solving method is provided from three aspects of near-end short-circuit protection, remote-end short-circuit protection, over-voltage protection and the like; the condition that the solid-state switch can be safely and reliably turned off under different short-circuit conditions is ensured; meanwhile, no maloperation of the solid-state switch in an intense electromagnetic interference environment is ensured; the short-circuit protection device of the solid-state switch has good reliability; and the short-circuit protection of the solid-state switch can be effectively achieved.

The invention discloses an automatic bridging device for preventing an open circuit of a storage battery. The automatic bridging device comprises a bridging module, a first wiring terminal, a second wiring terminal and a shell, wherein the bridging module is arranged inside the shell; the first wiring terminal and the second wiring terminal are fixedly arranged on the shell; the bridging module comprises a fuse, a high-power and low-power-consumption surface contact type diode and a CPU (Central Processing Unit) control panel; the CPU control panel is externally connected with a 12V direct-current power supply and is further connected with a normal work indicating lamp, a fan, a relay signal contact point and a warning indicating lamp; when the storage battery normally discharges electriccharges, the normal work indicating lamp is lighted; when the open circuit appears, the warning indicating lamp is lighted; and the location is immediately indicated and a warning signal is uploaded in time through the relay signal contact point. The automatic bridging device is small in size, is used for monitoring the storage battery in real time, is used for realizing seamless bridging, is usedfor realizing the self detection abnormity warning of the device, the open-circuit warning of the storage battery and the omnibearing abnormality warning of a voltage off-limit warning lamp of the storage battery, and meanwhile, has the remote transmission capacity of the warning signal.

The invention provides a reverse blocking IGBT shortcircuit protecting circuit, a method and a system thereof, and a storage medium. The reverse blocking IGBT shortcircuit protecting circuit comprisesthe components of a high-resistance resistor which is connected with the collector electrode of a reverse blocking IGBT; wherein the high-resistance resistor has the resistance which is higher than apreset value; a voltage difference detecting unit which is connected with the high-resistance resistor and is used for performing absolute value conversion on voltage; a comparator circuit which is connected the signal output end of the voltage difference detecting unit and is used for performing analog-to-digital conversion on the output voltage of the voltage difference detecting unit; a driving and detecting chip of which the overcurrent signal end is connected with the comparator circuit; and a DSP chip which is connected with the output end of the driving and detecting chip; wherein thereference ground end of the driving and detecting chip is connected with the output ground end of the voltage difference detecting unit. The driving end of the driving and detecting ship is connectedwith the driving circuit of the voltage difference detecting unit. Shortcircuit protection of the reverse blocking IGBT is realized, and damage of a driving protecting circuit is prevented.

The invention discloses a protection device, an air conditioning system and a protection method thereof. The device includes two or more of a reverse connection prevention unit, a voltage detection unit, a current detection unit, a short-circuit protection unit and a vibration detection unit; the reverse connection prevention unit is used for realizing reverse connection protection of an input power supply; the voltage detection unit is used for realizing under-voltage or over-voltage protection of the input voltage of the input power supply; the current detection unit is used for realizing active short-circuit protection of the input current of the input power supply; the short-circuit protection unit is used for realizing passive short-circuit protection of the input current of the inputpower supply; and the vibration detection unit is used for realizing automatic power-off protection of a vehicle which the air conditioning system to be protected belongs to. By means of the scheme,the problem that safety accidents are prone to being caused due to the fact that an electric-driven air conditioner is lack of protection measures can be solved, and the effect of improving the usingsafety of the electric-driven air conditioner is achieved.

The embodiment of the invention discloses a novel I-type three-level driving circuit applicable to NPC (Neutral Point Clamped) and ANPC (Active Neutral Point Clamped). The novel I-type three-level driving circuit comprises a digital control chip, a fault detection circuit and a push-pull amplification circuit, wherein the digital control chip is arranged at a primary side, the fault detection circuit is arranged at a secondary side, the digital control chip is used for detecting a fault through the fault detection circuit, the push-pull amplification circuit is used for amplifying a PWM (Pulse Width Modulation) control signal and further monitoring PWM instructions of four one-phase I-type three-level IGBTs (Insulated Gate Bipolar Transistors) and respective fault instruction, and the state of an arbitrary IGBT comprises the following three states: switch-on, switch-off and soft switch-off; and for each IGBT, the digital control chip is used for determining which all four tubes are in a state of the three states according to the current PWM instruction and the fault information of the digital control chip and by combining the PWM instructions and the fault information of the other three tubes and controlling the state of each IGBT.

The invention discloses a laboratory AC/DC power supply short-circuit protection device which is characterized in that the protection device is arranged between a power supply (1) and a load (18), and is composed of a fuse (2), an intermediate relay, a light-emitting diode, a resistor and a button which are in series-parallel connection. In the traditional process of experimental training, there is a need to frequently replace the fusible core of the fuse under the short-circuit condition of the load, which results in low teaching efficiency. What is worse, phenomena produced in the burning process of the fusible core of the fuse easily make students terrified of the debugging project, are not conducive to students' learning of specialized courses and improvement of practical skills, and hinder the cultivation of students' innovative thinking. With the device, the problems are solved effectively.

The invention relates to a short circuit protection circuit for a four-leg H-bridge driver chip. The short circuit protection circuit includes an H-bridge driving circuit, a timing circuit, and a switching circuit, a comparator, a short-circuit judgement result generating circuit and an H-bridge driving signal generating circuit that are sequentially connected to the H-bridge driving circuit, wherein the timing circuit is further connected to the short-circuit judgement result generating circuit, the switching circuit is connected between an internal power supply and a pin GND of a chip, and the H-bridge driving signal generating circuit is further connected to the H-bridge driving circuit. The short circuit protection circuit detects whether there is a short circuit condition between twoadjacent pins before the chip works normally, and if there is a short circuit, all H-bridge driving tubes can be turned off by generation of a protection signal, thereby preventing the chip from beingburnt out due to excessive current of the short circuit, and thus, short circuit protection of the four-leg H-bridge driver chip is achieved.

The invention relates to an automobile lamplight automatic control device with a protection function, and belongs to the technical field of automobile electrical appliances. A light sensation collecting circuit composed of an H-shaped bridge circuit formed by a photosensitive resistor and a fixed resistor is adopted to be connected with a voltage comparison circuit composed of two-level operational amplification circuits to form a control unit. A coupling loop composed of a forward-direction crystal diode and a resistor is arranged between the two-level operational amplification circuits, andan energy releasing loop composed of a capacitor and a resistor are in parallel connection with the position between the connecting position of the forward-direction crystal diode and the resistor andthe ground; and a deep negative feedback direct current amplification output circuit is adopted to form a driving control and protection circuit, wherein the deep negative feedback direct current amplification output circuit is formed by sequential connecting of an NPN-type transistor and a PNP-type transistor, and the output end of the driving control and protection circuit is connected into a direct current voltage-regulator diode in a bridging mode. The automobile lamplight automatic control device with the protection function has the advantages that the structure is simple, performance isreliable, a breakdown disappears, automatic restoring can be achieved, and maintenance is not required, the cost is low, application and popularizing are easy, applicability is high, and the automobile lamplight automatic control device can be combined with lamplight systems of various structures.

The invention relates to an intelligent miniature circuit breaker which comprises a shell and a handle, an operating mechanism, a tripping mechanism and an electric breaking-closing mechanism which are arranged in the shell, wherein the electric breaking-closing mechanism comprises a circuit board, a motor, a worm, a turbine, a linkage gear, a driving gear and a handle gear; a metering unit is arranged on the circuit board, the circuit board is arranged between the tripping mechanism and the shell, the motor is arranged on the circuit board, the worm is connected to an output shaft of the motor and is in linkage connection with the linkage gear and the driving gear by the turbine, the turbine and the linkage gear are arranged between a contact board and a circuit board, a section driving gear is fixed on the driving gear and is meshed with the handle gear, the handle gear is a section gear and is coaxially connected with a handle, and the handle is connected with a jump pin by a connecting rod. According to the invention, the functions of electric energy metering, short circuit protection, electronic protection, fee-controlled breaking and automatic reclosing are realized in one module.

The invention provides a lithium-ion battery and a manufacturing method thereof. The lithium-ion battery comprises a battery shell and a battery cell monomer arranged in the battery shell, and an inner wall of the battery shell is provided with an expandable graphite coating. The manufacturing method of the lithium-ion battery comprises the following steps: preparing a coating material, wherein the main components of the coating material comprise expandable graphite, pentaerythritol, ammonium polyphosphate, melamine and matrix resin; coating an inner wall of the battery shell with the coatingmaterial, and forming the expandable graphite coating on the inner wall of the battery shell; and assembling the battery cell monomer into the battery shell of which the inner wall is provided with the expandable graphite coating. After the expandable graphite is heated and expanded, the volume is rapidly increased, a battery cell is rapidly wrapped, the battery cell is prevented from being in contact with outside air, and a flame-retardant effect is achieved, so that short-circuit protection in the battery cell is realized.

The invention provides a light emitting diode (LED) short-circuit protection system. The LED short-circuit protection system comprises a power module, an execution protection unit, a signal acquisition unit and a signal processing unit, wherein the power module is used for supplying power to a load LED light source and a circuit, the execution protection circuit is used for performing outage protection on the system when a short-circuit fault occurs in the load LED light source, the signal acquisition unit is used for acquiring a short-circuit signal in real time to detect the system, and the signal processing unit is used for judging the short-circuit fault according to the acquisition signal of the signal acquisition unit and controlling the execution protection unit to perform short-circuit protection. By the LED short-circuit protection system, the problem that a power output LED system cannot be protected in short circuit can be solved, a power supply or a control circuit can be locked when an output LED is circuit-shorted, the short-circuit protection of the power output multi-path LED system is achieved, a large current is simultaneously prevented from instantaneously being output in short circuit, a circuit component is prevented from being broken down by an instantaneous current, a load such as the LED is protected, and the power supply and a subsequent circuit part also can be prevented from being damaged. The LED short-circuit protection system has the characteristics of simple circuit, relatively low cost and high reliability and is beneficial for promotion.