40results about How to "To achieve the purpose of current limiting" patented technology

The invention discloses an adaptive input power charger and a method for controlling an input current of a charger. An input voltage of the charger is compared with a first reference voltage through a comparison circuit to generate a comparison result; and when the comparison result represents that current of input power is limited, a current regulation circuit controls the duty ratio of a power switch tube according to the comparison result to limit the input current of the charger so as to remove a current-limiting state of the input power. In addition, when the comparison result represents that the current of the input power is not limited, the current regulation circuit can also increase the current reference value of a current control loop according to the comparison result to increase charging current so as to achieve the purpose of quick charging. The adaptive input power charger can be used for adaptively performing current-limiting protection according to different input voltages, so that the adaptability is good.

The invention relates to a linear voltage stabilizer with current-limiting short circuit protection. The linear voltage stabilizer comprises a starting circuit, a reference voltage circuit, a comparison amplifying circuit, a short circuit protection circuit, a current sampling circuit, a voltage sampling circuit and an adjusting pipe, wherein the starting circuit delivers the input voltage sourceinto the reference voltage circuit; the reference voltage circuit provides the adjusted reference voltage to the comparison amplifying circuit; an output end of the adjusting pipe is connected in series with the current sampling circuit; the current sampling circuit feeds back the sampled output current signal to the comparison amplifying circuit; the voltage sampling circuit feeds back the sampled output voltage signal to the comparison amplifying circuit; the comparison amplifying circuit processes the output current signal and the output voltage signal and delivers to a control end of the adjusting pipe so that the adjusting pipe works in a linear area and the aim of current limiting and voltage regulation is achieved; and the short circuit protection circuit processes the acquired output voltage signal and delivers to the control end of the adjusting pipe so that the adjusting pipe is adjusted from the linear area to a shutoff area and the aim of short circuit protection is achieved.

The invention discloses a novel excavator current-limiting control system, belonging to the field of electrohydraulic control of hydraulic excavators. The novel excavator current-limiting control system comprises a master controller, a main pump proportional valve, a getting-down pressure switch S2, a getting-on pressure switch S1, and a rotation speed sensor and further comprises a revolution pilot pressure sensor, a P1-pump outlet pressure sensor, a P1-pump current-limiting pressure sensor, a P2-pump current-limiting pressure sensor, a P2-pump maximum-flow control proportional valve and a P1-pump maximum-flow control proportional valve, which are respectively and electrically connected with the master controller. The novel excavator current-limiting control system has the beneficial effects that: the flexibility in model selection of hydraulic elements can be enhanced, meanwhile, a rotary motor and a travelling motor can be prevented from being damaged by overlarge flow of a hydraulic system; in addition, the actions in need of current limitation can be judged through a detection device so as to prevent 'one size fits all' type current limitation, the pump displacement of two single pumps can be limited through controlling the current of the two current-limitation proportional valves, closed-loop control is adopted for a current control loop of the proportional valves, and thus the accurate current-lamination control is realized.

The invention provides a linkage regulation and control method for the passenger flow of a station. The method comprises the following steps of detecting and calculating the number of passengers on a platform and the number of passengers in a transfer tunnel in real time; calculating passenger capacity balances of the transfer tunnel and the platform and a difference value between the passenger capacity balances; calculating linkage flow limiting comprehensive indexes of each associated non-transfer station, wherein the number of the passengers is required to be reduced after flow limitation; regulating the number of the passengers entering the platform in a transfer station according to the passenger capacity balance of the platform, and if the number of the passengers of the platform is greater than the passenger capacity of the platform, starting a linkage flow limiting measure to achieve the aim of flow limitation according to the linkage flow limiting comprehensive indexes. According to the scheme, the numbers of the passengers of the platform and the transfer tunnel of the transfer station are detected as parameters in real time, and an algorithm is accurate and scientific; a linkage flow limiting control measure is adopted for the linkage regulation and control flow limitation of the associated non-transfer stations in a way of combining local flow limitation of the transfer station and flow limitation of the associated non-transfer stations, flow limiting means is systematic, comprehensive and high in timeliness, and the phenomenon of congestion of the station can be timely eliminated.

The invention discloses a series-connection current limiting circuit of a miner lamp intrinsic safety power supply. The series-connection current limiting circuit of the miner lamp intrinsic safety power supply is characterized by comprising a DC/DC (Direct Current/ Direct Current) boosted circuit, a control circuit, a reference power supply, a current sampling circuit, a voltage sampling circuit and a three-stage series-connection power adjusting and protecting circuit, wherein the DC/DC boosted circuit is formed by an IC1 (Integrated Circuit), diodes, capacitors and a resistor and is used for supplying a control power supply; the control circuit is formed by an IC2 and resistors and used for setting and comparing the voltage and the current; the reference power supply is formed by an IC3, a resistor and a capacitor and is used for supplying the preset control voltage for a '+' input end of the IC2; the current sampling circuit is formed by a resistor R1 and a resistor R2, and the voltage sampling circuit is formed by a resistor R12 and a resistor R13, and the current sampling circuit and the voltage sampling circuit are respectively used for supplying the preset control voltage for a '-' input end of the IC2; and the three-stage series-connection power adjusting and protecting circuit is formed by an FET2 (Field Effect Transistor), an FET3 and an FET4. According to the series-connection current limiting circuit of the miner lamp intrinsic safety power supply, disclosed by the invention, the current limiting circuit is formed by applying power semiconductor devices and other electronic devices, and the situations that when in normal work, the inner resistances of the devices are kept to the lowest, and no influence on the working performance of loads is realized; and the inner resistances of the devices can be increased immediately when the loads are in over current or short circuit failure, the failure current can be immediately limited within the safety current, and thus the miner lamp power supply can be safely protected.

The invention belongs to the technical fields of electronics and power supplies and discloses a high-power adjustable voltage-stabilized power supply manufactured by a reference voltage source. The voltage-stabilized power supply consists of an alternating current (AC) transformer B and a full-bridge rectifying circuit, a half-wave rectifying and filtering circuit, an adjusting tube BG1, a sampling amplifying circuit, a current-limiting protection circuit and a voltage-dividing and sampling circuit, and is characterized in that: the sampling amplifying circuit consists of a three-end adjustable current-dividing reference voltage source IC1 and a resistor R1; the adjusting tube BG1 is an enhanced N-channel high-power field-effect tube; the current-limiting protection circuit consists of a silicon triode BG2 and a current sampling resistor R2; and the voltage-dividing and sampling circuit consists of a potentiometer RP and a voltage-dividing resistor R3. The adjustable voltage-stabilized power supply outputs heavy current and adjustable voltage, the circuit has an overcurrent protection function, and particularly the conversion efficiency and working reliability of the adjustable voltage-stabilized power supply are improved.

The invention relates to the field of an alternating current and direct current mixed micro electric network and a power distribution network, in particular to an alternating current and direct current mixed micro electric network and power distribution network circuit link and a control method. The circuit link comprises a subordinate voltage source current converter, a three-phase LC low-pass filter and a three-phase voltage transformer, wherein the direct current side of the subordinate voltage source current converter is connected with the direct current bus of the alternating current anddirect current mixed micro electric network; the alternating current side of the subordinate voltage source current converter is connected with one end of the three-phase LC low-pass filter through athree-phase conducting wire; the other end of the three-phase LC low-pass filter is connected to the secondary side of the three-phase transformer; the primary side of the three-phase voltage transformer is connected in series between the alternating current bus of the alternating current and direct current mixed micro electric network and the power distribution network. The circuit link has the advantages that the voltage compensation and current limitation effects are achieved; the voltage stability of a load of an alternating current bus in the alternating current and direct current mixed micro electric network can be ensured; the safety of the electric power electronic devices in the alternating current and direct current mixed micro electric network is also ensured.

The invention provides a high-voltage LDO (Low Dropout Regulator) circuit with a clamping current limiting function. The high-voltage LDO circuit is used for solving problems that a traditional high-voltage LDO is too large in area and not high in performance, an output driving tube is too high in gate-source voltage and prone to being damaged, and the output current of the LDO is limited. The circuit comprises three NMOS (N-channel Metal Oxide Semiconductor) tubes M1 to M3, four resistors R1 to R4, a capacitor C1, four voltage stabilizing diodes D1 to D4 and an error amplifier AMP; three voltage stabilizing diodes are connected in series at an input end to reduce an input high voltage to a low voltage range, a circuit can be designed by adopting a lower voltage-resistant device, a grid electrode and a source electrode of an output driving tube are connected with the voltage stabilizing diodes, and a purpose of limiting the output current is achieved by adopting the stabilized voltage value. A photomask layer is reduced while the driving capability is improved, the circuit is simple, and cost can be reduced.

The invention discloses a karst underground river water sample sampling device and a sampling method. The sampling device includes a water storage device and a supporting rod; the water storage device includes a water inlet cabin and a water storage cabin which are in up and down arrangement and mutual communication; the water inlet cabin has a water inlet, and the water inlet is provided with adjustable water inlet baffle plates and a protective screening; the positions, close to the two vertical sides of the water inlet, on the inner wall of the water inlet cabin are respectively provided with longitudinal inserting grooves; the adjustable water inlet baffle plates are interspersed in the two longitudinal inserting grooves; the top of the water inlet cabin is provided with a protective cover; the water storage cabin has a drainage outlet, and the outer circumferential wall of the water storage device is provided with fixing sleeves; the supporting rod consists of a connecting rod and a rod head; the connecting rod is provided with more than one through holes passing through the lateral width of the connecting rod; and the relative fixing of the supporting rod and the water storage device can be realized through a screw thread pair when the supporting rod is inserted into the fixing sleeves on the outer circumferential wall of the water storage device. The device is low in cost and has various functions of convenient carrying, current limiting, depth keeping and multiple measurement.

The invention provides a radial-inserting and radial-throttling type throttler and a balance sieve tube employing the same, wherein the throttler is used for controlling liquid flow of a liquid channel, and comprises a throttler main body and a throttler supporting disc; overflowing parts are radially arranged in an overflowing part mounting hole on the throttler main body, and the overflowing parts include a non-porous type and a porous type, and when the overflowing parts belong to the porous type, different amounts of overflowing holes are formed on the overflowing parts; the balance sieve tube comprises the liquid channel, namely a base pipe, a composite filtering sleeve component and the radial-inserting and radial-throttling type throttler, the composite filtering sleeve component and the throttler are coaxially sleeved on the periphery of the base pipe, and the composite filtering sleeve component comprises an inner protective jacket, a multi-layer filtering wire mesh and an external protective jacket. With rational combination of the overflowing parts having different amounts of holes, the overflowing holes on the base pipe can easily change between opening and closing and become larger and smaller, thereby realizing the purpose of throttling.

The invention provides a constant power ballasting component, comprising: a magnetic core; a main coil arranged in the magnetic core, wherein the main coil at least includes a first tap, a second tap, a third tap and a fourth tap, wherein a coil of first number of turns is arranged between the first tap and the third tap, a coil of second number of turns is arranged between the first tap and the second tap, and a coil of third number of turns is arranged between the first tap and the fourth tap; a control unit that detects an input voltage and switches on one of the second, third and fourth taps and the first tap selectively according to the input voltage. The constant power ballasting component allows the corresponding number of turns to be adjusted and the tapping to be performed during winding of a choke coil according to voltage fluctuation, so that a lamp is kept operating substantially under the rated power to save energy.

The invention relates to a three-phase short-circuit failure restrictor based on an IGBT (Insulated Gate Bipolar Translator), belonging to the technical field of electric power application. The three-phase short-circuit failure restrictor is composed of six IGBT modules, three electric reactors, three capacitors and three current sensors, wherein the three IGBT modules form an upper bridge arm, and the other three IGBT modules form a lower bridge arm; collector electrodes of the three IGBT modules of the upper bridge arm are respectively three incoming line terminals, and emitting electrodes of the three IGBT modules, the collector electrodes of the three IGBT modules of the lower bridge arm and one end of each of the three electric reactors are respectively corresponding connected together; the emitting electrodes of the three IGBT modules of the lower bridge arm are connected, the other ends of the three electric reactors are respectively connected with one end of each of the three capacitors so as to respectively pass through the three current sensors to form three outgoling line terminals; and the other ends of the three capacitors are connected together. A short circuit fault appeares in an electric system, the three-phase short-circuit failure restrictor can rapidly recognize and rapidly response, and can be applied in electric networks of different voltage grades.

The invention provides a drainage pipeline flow limiting adjusting device. The problems that an adjusting valve installed on a large drainage pipeline is complex in structure, consequently, assembling is not easy, and the manufacturing cost is high are solved. The drainage pipeline flow limiting adjusting device comprises a steel pipe; flange plates are fixedly arranged at the upper end and the lower end of the steel pipe; an annular baffle is arranged in the steel pipe and is perpendicular to the inner wall of the steel pipe; a water flowing hole is formed in the middle portion of the annular baffle; a cone capable of moving up and down is arranged in the water flowing hole; the diameter of the bottom of the cone is equal to the inner diameter of the water flowing hole; a vertical tooth plate is arranged at the bottom of the cone; a sliding way component is arranged on the inner wall of the cone; the tooth plate is inserted in a sliding way clamping plate of the sliding way component in a sliding manner; the sliding way clamping plate is of a frame type plate structure with a front opening; a limiting plate preventing the tooth plate from disengaging is arranged at the front portion of the sliding way clamping plate; a gear engaged with the tooth plate is arranged in the steel pipe; the middle portion of the gear is connected with a transversely-arranged shaft rod component; and a shaft hole is formed in the wall body of the lower portion of the steel pipe, and the other end of the shaft rod component penetrates out of the shaft hole to be connected with a hand wheel.

The invention discloses a current limiting circuit of a high-voltage large-current linear voltage regulator and an implementation method, the current limiting circuit is connected with a variable resistor R1 and a variable divider resistor R2 through a drain electrode of a high-voltage output power tube M1, one end of the variable resistor R1 is used as an output voltage VOUT port, a load equivalent resistor RL generates an output current Iout, the output current Iout flows through a sampling resistor Rsense, a voltage difference is generated between the two ends of the sampling resistor Rsense, the voltage difference is transmitted to a current induction amplifier I3, the current induction amplifier I3 amplifies a sampling signal and outputs voltage to a current limiting comparator I1, the current limiting comparator I1 compares the output voltage of the current induction amplifier I3 with reference voltage Vref input by the current limiting comparator I1, and therefore current limiting is achieved. The current limiting circuit is scientific and reasonable, is safe and convenient to use, can very accurately correspond to the actual loading capacity through aluminum wiring resistance sampling on the active region of the output end of the high-voltage power tube M1, and timely realizes current limiting.