171results about How to "Stable output current" patented technology

The invention discloses a band-gap reference voltage circuit. A current source is additionally arranged, a reference voltage output end and a power source end are arranged, density of current flowing through a second triode is n times of the density of current flowing through a first triode in a micro current source unit, a power supply end of a difference amplifier unit is connected with the power source end, a collector of a third triode is connected with the power source end through the current source, an emitting electrode of the third triode is connected with an input end of the micro current source unit, the collector of the third triode is connected with an output end of the difference amplifier, and a connecting point and a base electrode of the third triode are both connected to a reference standard output end. As an implementation mode of the micro current source unit, resistance value of a third resistor is n times of that of a second resistor, and the first triode is symmetrically matched with the second triode. The band-gap reference voltage circuit is high in accuracy, low in power source noise, small in temperature coefficient, low in power, capable of directly generating reference voltage over 1.25V, needless of being connected with a peripheral resistor for working and suitable for generating reference voltage inside a chip.

The invention provides a battery management method, a battery management device and equipment powered by a battery, and relates to the technical field of communication. Harmful effects caused by bias current and ring current can be controlled effectively, and the bias current and the ring current are generated when batteries or battery packs of different capacities and materials are directly utilized in parallel. The method is capable of managing two or more than two parallel batteries or battery packs in a circuit, and a parallel branch is formed by the branch where each parallel battery or battery pack is located. The method comprises: whether a current value of a target parallel branch is larger than a preset current value or not is detected; when the detected current value of the target parallel branch is larger than the preset current value, the current value of the target parallel branch is adjusted to be smaller than or equal to the preset current value. The battery management method is used for management of parallel batteries.

A display device including a timing control circuit, a programmable voltage generator, a gate driver, a source driver circuit and a display panel is provided. The display panel includes a plurality of redundancy pixel cells and display pixel cells. The redundancy pixel cells and display pixel cells may include a—Si TFT and organic light emitting diode. The redundancy pixel cells and display pixel cells may be turned on by the gate driver circuit, and the working current of each display pixel cell may be compared with that of the corresponding redundancy pixel cell. Then timing control circuit may control the programmable voltage generator to generate applicable voltage of data to the source driver circuit to compensate the shift of the working current of the display pixel cells after working a period of time according to the comparison result.

The invention provides a method for simultaneous and integrated electric energy outputting by a solar cell fabric unit and a friction nano generator. The method comprises: the solar cell fabric unit is formed by direct intersected braiding or wound connection of photo-anodes having fiber structures and counter electrodes of the fiber structures; the friction nano generator is formed by two electrodes having different interfacial electron adsorption capacities, wherein one electrode is equipped with negative electricity and the other electrode is equipped with positive electricity after the two electrodes are in contact and then are separated; elements having unidirectional conduction characteristics are connected to the photo-anodes or counter electrodes of the solar cell fabric unit and then parallel connection with the two electrodes of the friction nano generator is realized, thereby matching electrical output characteristics of the solar cell fabric unit and the friction nano generator and thus realizing simultaneous and integrated outputting. Therefore, a technical problem that the friction nano generator with the high output impedance is easy to be in a shot circuit state by the low-impedance solar cell can be solved. The provided integration solution has advantages of light weight, easy integration and prevention of manual adjustment all the time.

The invention discloses a program-control delay startup high-stability large-current driver, which can control the output voltage of a high-precision digit / analogue converter via a microprocessor, control the output current of load, control a current adjustment circuit via a MOS tube to improve the output current and efficiency. The invention adds a delay startup circuit to slowly increase the load output current without abrupt change. The driver adds a high-precision sampling resistance in load to measure the current fluctuation on the load and connects the control voltage of the output current and the voltage on the sampling resistance with two inputs of a comparator via voltage amplification to form a close-loop negative feedback technique to stabilize the output current with high reliability. The invention has simple circuit, while the output drive current can reach 2A, with continuous program control and adjustable property. The invention has stable and reliable output current and low voltage impact, under the connection with different loads. The invention has wide application in constant-current control and high power LED luminous technical fields.

The invention discloses an LED driving circuit and a driving method. The driving circuit comprises a control chip, a constant current driving module, a first switch tube, a second switch tube and a third switch tube, wherein a first LED particle, the first switch tube and the constant current driving module are connected in series to form a loop; a second LED particle, the second switch tube and the constant current driving module are connected in series to form a loop; a third LED particle, the third switch tube and the constant current driving module are connected in series to form a loop; the control chip is electrically connected to the control end of the constant current driving module, the control end of the first switch tube, the control end of the second switch tube and the control end of the third switch tube. According to the LED driving circuit and the driving method, working conditions of different LED particles can be controlled according to luminance, color temperature and color requirements set by a user to achieve the set effect, output current is stable without current overshoot, and extra power consumption is reduced.

The invention relates to a self-feedback linear galvanostat integrating an adjustable thermistor, which belomngs to the technical field of a semiconductor power device. The self-feedback linear galvanostat comprises a junction-type field effect transistor (JFET) and an adjustable thermistor, which are integrated together, wherein one end of the adjustable thermistor is connected with a JFET source electrode, and the other end is connected with a grid electrode of the JFET. The self-feedback linear galvanostat is centralized on the adjustable thermistor, and the adjustable thermistor can obtain a resistance value meeting the requirement of the output current through a laser cutting way, so that different types of products can be obtained in the same batch. The thermistor is a positive temperature coefficient, under the working situation, the temperature is increased, the resistance is increased, the output current is reduced, and the reliability of an application system is protected. The self-feedback linear galvanostat has advantages of high integration, stability in output current, adjustability of the current and good temperature property and can be applied to the fields such as light emitting diode (LED).

The invention discloses a step-down power supply ripple detection and compensation circuit, which comprises a current ripple collection circuit and a compensation current ripple generation circuit after a load is connected to a switching power supply in parallel. By an on-chip compensation technology, integral voltage corresponding to inductive current is obtained through integration by collecting a voltage change of an inductor in the switching power supply; compensation current opposite to the inductive current is obtained by differencing the integral voltage and the voltage of the switching power supply; and the obtained compensation current is injected into a primary circuit to offset current fluctuation caused by the inductor in the switching power supply, so that compensation of ripple current is achieved; constant-current output can be achieved only by adding a small-capacity ceramic capacitor and an appropriate resistor; output current is stable and a large electrolytic capacitor is not needed; the disadvantage that the service lifetime of a product is short due to the adopted large electrolytic capacitor with short service lifetime in the prior art can be compensated; the circuit is simple in structure, high in stability, wide in application range and small in volume; and the service lifetime of the product can be effectively prolonged.

The invention discloses a circuit structure of a narrow-pulse-width high-repetition-frequency pulse current source. The circuit structure is characterized by comprising an adjustable reference voltage input module (1), a current source module (2), an adjustable narrow pulse generating and shaping module (3), a high-speed selection module (4) and a current mirror module (5), wherein the adjustable reference voltage input module (1), the current source module (2) and the current mirror module (5) are electrically connected in sequence; and the adjustable pulse generating and shaping module (3), the high-speed selection module (4) and the current mirror module (5) are electrically connected in sequence. By adopting the circuit structure, the pulse width, the current magnitude and the pulse frequency can be adjusted. Moreover, the circuit structure has the advantages of narrow pulse width, high repetition frequency, high current, small overshoot and steep leading edge.

The invention relates to a high-adaptive charging system and method for an electric vehicle. The system comprises a power battery pack, a battery management system, a charging interface, a charging positive relay, a charging negative relay and a structure conversion relay group, wherein the charging positive relay comprises a positive relay in a common charging mode, a positive relay in a high-voltage charging mode, and a positive relay in a low-voltage charging mode. The structure conversion relay group controls the series-parallel connection structure of the battery pack, adjusts the charging voltage of the electric vehicle, and adjusts the charging voltage of the battery pack under the allowable charging current of a charger in order to adapt to a connected charging pile. For a high-voltage high-power charger, the system increases the charging voltage of the battery pack and the charging power of the battery pack, shortens the charging time, and improves the adaptability of the electric vehicle to long-distance driving. For a low-voltage charger, the system reducing the charging voltage of the battery pack, makes the battery pack compatible with the low-voltage charger, and reduces the dependence of the electric vehicle on general charging infrastructure.

An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current 5 river receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.

The invention discloses a current mirror circuit, which comprises an n-channel metal oxide semiconductor (NMOS) tube N1, an NMOS tube N2, an NMOS tube N3 and a p-channel metal oxide semiconductor (PMOS) tube P1, wherein the drain of the NMOS tube N1 is connected with a circuit voltage drain drain (VDD) through a constant current source Ib1, the grid of the NMOS tube N1 is in short-circuit connection with the drain of the NMOS tube N1, the grid of the NMOS tube N1is grounded through a capacitor C2, and the source of the NMOS tube N1 is grounded; the drain of the NMOS tube N2 is connected with the output end through a switch S1, the grid of the NMOS tube N2 is in short-circuit connection with the drain through a capacitor C1, and the source of the NMOS tube N2 is grounded; the drain of the NMOS tube N3 is connected with the circuit voltage drain drain (VDD) through a constant current source Ib2, the grid of the NMOS tube N3 is connected with grids of the NMOS tube N1 and the NMOS tube N2, and the source of the NMOS tube N3 is grounded; and the source of the PMOS tube P1 is connected with the grid of the NMOS tube N1, the grid of the PMOS tube P1 is connected with the drain of the NMOS tube N3 and the drain of the PMOS tube P1 is grounded. According to the current mirror circuit, when the voltage of a node A exceeds a certain value, the current release capacity of the node A is improved by a feedback circuit inside an accelerating circuit to quickly and steadily output current, and time for outputting steady current can be shortened.

The invention provides a power management circuit and a chip thereof. The power management circuit comprises a pre-voltage stabilizing module, a linear voltage stabilizing module, and a bias current generation module. Input voltages sequentially pass through the pre-voltage stabilizing module, the linear voltage stabilizing module, and the bias current generation module to generate a pre-stabilized voltage VPR, a voltage stabilizing voltage VREG, and a bias current Ibias separately. The power management circuit in the chip provides a power supply voltage and a current bias for modules in the chip. The invention has the advantages that the circuit can generate stable voltages at high input voltage conditions to provide stable power supply for each module in a power management IC (IntegratedCircuits); output currents are stable, and the driving capacity is large; the power consumption of the power management circuit is low, helping to control the overall power consumption of the chip; and the circuit structure is easy to realize so as to be suitable for engineering application.

The invention belongs to the field of electronic technology, and relates to an inductively coupled power transfer (ICPT) device with a pull-down auxiliary switch. A group of pull-down auxiliary switch branch is added to an LC resonant single tube inverting bipolar inverting circuit topology used by the existing ICPT device, the branch comprises an auxiliary switch tube, a main switch tube and the auxiliary switch tube have the same switch frequency, soft switch control can be both realized, no shoot-through problem exists between the two tubes, and the reliability is improved. In a condition of keeping the advantages of the original circuit, voltage borne at two ends of the switch tube is reduced to 2 / 3 the original voltage, the device can adopt a metal oxide transistor as a switch tube, the switch frequency can reach more than 83kHz, and as the auxiliary switch tube is short in turn-on time and low in power consumption, a technical scheme for furthering reducing the size and the weight of the ICPT device and reducing the cost is provided.

An output driver has an output multiplexor and an output current driver. The output multiplexor receives a data signal and outputs a q-node signal. The output current driver receives the q-node signal and drives a bus based on the q-node signal. The output multiplexor processes the data signal in various ways to generate the q-node signal. The output current driver is responsive to current control bits to select a amount of output drive current. In addition, the output multiplexor is controlled such that the output impedance of the output current driver is maintained within a predetermined range.

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 low dropout linear voltage regulator with a large output current range, and belongs to the field of integrated circuit design. After output voltage of an LDO (Low Dropout Regulator) is subjected to voltage division sampling, feedback voltage is obtained; the feedback voltage and reference voltage are input into an error amplifier; after being amplified, a voltage difference is supplied to a controller realized by a digital circuit; the controller outputs a control word to adjust on and off of current of each branch, so that the LDO can output stable current; each branch is formed by connecting a switch tube with a current source in series; all the branches are connected in parallel and are connected between a power supply and the output voltage; particularly, the controller converts an input analog signal into a digital signal through a digital-to-analog converter and then processes the digital signal through a digital logic control circuit to obtain the control word, so as to control on and off of multiple current branches consisting of the current sources and switches, and obtain required output current. The multiple parallel-connected current branches supply the output current, so that the low dropout linear voltage regulator is relatively large in output voltage range; each branch comprises the current source and the switch which are connected in series; the output current is stable.

The invention discloses an electronic system, a power amplifier and a temperature compensation method of the power amplifier. The power amplifier comprises a bias circuit, an output stage circuit and a compensation circuit. The bias circuit is used for providing reference voltage. The reference voltage is the sum of first voltage with positive temperature coefficient and second voltage with negative temperature coefficient. The output stage circuit receives working voltage. The compensation circuit receives compensation current, with the negative temperature coefficient, transmitted by the bias circuit and provides compensation voltage with the negative temperature coefficient to the output stage circuit through the bias circuit. The working voltage is the sum of the reference voltage and the compensation voltage. The power amplifier stabilizes the input current of the output stage circuit through the compensation circuit or stabilizes the output current by adjusting the input current into the positive temperature coefficient when the ratio constant between the output current and the input current of the output stage circuit is the negative temperature coefficient.

The invention discloses an energy-saving LED strong light device comprising a base plate, an LED, a light source reflection bowl, a radiator and a translucent lampshade. The energy-saving LED strong light device has the main technical points that connected light source reflection bowl structures are evenly distributed on the convexity of an arc-shaped heat conduction base plate, the inner side of each light source reflection bowl is provided with an LED, the back end part of the LED is connected with the arc-shaped heat conduction base plate, and the edge of the light source reflection bowl structure is convex honeycomb-shaped structure; the radiator is arranged on the concavity of the arc-shaped heat conduction base plate; a power supply driving controller is connected between the LED and the power supply which are connected in series; the power supply driving controller respectively comprises a limited current circuit, a voltage doubling rectifying circuit and a constant current circuit, wherein the voltage doubling rectifying circuit is connected with the output end of the limited current circuit, and the constant current circuit is connected with an output end of the voltage doubling rectifying circuit. As all LEDs in a lamp are connected in series, the constant current circuit provides stable output current for LEDs connected in series, which relatively improves the service life of the LEDs. The invention also has the characteristics of safety, reliability, wide application range and the like.

The invention discloses a complementation-metal-oxide semiconductor constant potential rectifier with rapid stability characteristic, relating to the weak current detection technology of sensors; the complementation-metal-oxide semiconductor constant potential rectifier comprises an operational transconductance amplifier (OTA), a NMOS tube, a switch for rapid charge, and an in-chip and out-chip voltage stabilization and noise filtration capacitor; the output end of the operational transconductance amplifier (OTA) is connected with the grid electrode of the NMOS, the source electrode of the NMOS is connected with the inverted input end of the operational amplifier, so as to form a current conveyer, and the drain electrode of the NMOS is used as the output end of a constant potential rectifier; the switch is connected at the non-inverting input end and the inverted input end of the operational transconductance amplifier in a bridging way, and the control end of the switch is connected to the setting end of the system. In the invention, the stability of the voltage of the working electrode of the sensor can be enhanced, and the circuit with any current can enter in a detection state rapidly, and the constant potential rectifier leads the drain electrode of the NMOS to close to ideal constant flow source output.

Provided is a voltage regulator capable of reducing fluctuation of an output current even when an output terminal thereof is short-circuited. In a case where the output terminal of the voltage regulator is short-circuited, an output current (Iout) of the voltage regulator is limited and fixed to a limit current value. When an output voltage (Vout) of the voltage regulator decreases to have a value equal to or smaller than not a detection voltage value (Vref3) of a reference voltage circuit (34) but a detection voltage value (Vref2) of a reference voltage circuit (31), a second limit operation in which the output voltage (Iout) is further limited to be decreased is set. Further, in a case where the output terminal is short-circuited and then reset, when the output voltage (Vout) has a value equal to or larger than not the detection voltage value (Vref2) but the detection voltage value (Vref3), the second limit operation is canceled.

The invention discloses a variable gain amplifier, which comprises a current adjustable amplifying circuit and a compensating circuit; wherein the current adjustable amplifying circuit can change the gain according to a control voltage; while the output terminal of the compensating circuit is connected with the output terminal of the current adjustable amplifying circuit, and provides direct compensating current to the adjustable amplifying circuit; the sum of the direct compensating current and the output current of the current adjustable amplifying circuit is equal to the current source current of the current adjustable amplifying circuit. The output current of the variable gain amplifier is relatively stable, which reduces the change of a common mode output level, thereby reducing the influence on the next-stage circuit offset.

The invention relates to a three-level Cuk voltage regulation constant current source and an operation method of the three-level Cuk voltage regulation constant current source, and relates to an alternating current power source realizing constant current output through feedback and adjustment of the output current. The three-level Cuk voltage regulation constant current source comprises a control part and an execution part. The control part comprises a single-chip microcomputer, a three-level Cuk voltage regulation circuit, a PID controller, keys, a 485 communication hardware circuit, a voltage zero crossing point detection circuit, a current zero crossing point detection circuit and a current instantaneous value collecting circuit. The execution part comprises a PWM signal generation circuit, an IGBT driving circuit and a displayer. The control part with the single-chip microcomputer as the core can directly and automatically detect the instantaneous value of load current and carries out logic judgment on the instantaneous value of the load current and the instantaneous value corresponding to a set value. When the instantaneous value of the load current changes, the load current can be made constant by regulating the changes of voltage, and therefore the defects that an existing constant current source is slow in constant regulation process of current, poor in stability and large in size are overcome.

The present invention discloses an RF power amplifier which adopts a single chip design without reference voltage, and the RF power amplifier includes a three-terminal current source circuit, a current mirror circuit and an output stage circuit. The three-terminal current source circuit receives a first system voltage and outputs a first current and a second current based on the first system voltage, and a source voltage exists between a first output point of the first current and a second output point of the second current. The current mirror circuit receives the first current and the second current, and generates a bias current based on the first current and the second current. The output stage circuit receives the bias current to work at an operation bias point. The RF power amplifier enables the first system voltage to be between the first voltage and the second voltage through the source voltage of the three-terminal current source circuit, so that the output stage circuit outputs an output current which does not change along with the first system voltage, and which has temperature compensation.

The invention discloses a DFIG system control method based on a repetition sliding mode. A repetition controller is added to a construction sliding mode face, so the system has the capability in controlling any harmonic wave. Through the method, motor electromagnetic torque ripples caused by power grid voltage harmonic waves and harmonic waves of the output current of the system can be eliminated, and prolongation of the life of the blower fan machinery and wind-electricity grid connected harmonic wave standards can be satisfied. According to the method, extraction for each harmonic component is not required, adding extra resonance controllers is not required, control on any subharmonic wave can be realized, and the method makes the system be applicable.

The invention relates to an LED lighting circuit, which is characterized in that a constant flow source which comprises a voltage-regulator tube D3, a fifth current-limiting resistor R5 and a triode Q1 is additionally arranged in the traditional LED lighting circuit. Since the constant flow source is additionally arranged in the traditional LED lighting circuit, and the most notable effect of the constant flow source is stable output current, the output reliability is ensured; even if voltage has fluctuation, the output can not be influenced, and the current output to each branch is constant, and therefore, users can add the number of LED light-emitting diodes according to self needs. The users not only can add the number of the LEDs but also can put the LEDs or change the colors of the diodes at will, and for example, some festive products can be added with colorful light-emitting diodes.

The invention discloses a mobile phone tablet computer having a built-in ultra-thin universal serial bus (USB) device. The mobile phone tablet computer comprises a shell of the mobile phone tablet computer, a mainboard, a supply circuit and a functional circuit. The mobile phone tablet computer is characterized in that the mainboard of the mobile phone tablet computer is connected with an ultra-thin USB charging and / or data-transmission device which can be used for straight cutting of an A type USB mother port, the USB interface standard of the device is USB 2.0 or USB 3.0, and the thickness of the device is usual 2-3 millimeters. The ultra-thin USB device is arranged inside the shell or a groove part of the mobile phone tablet computer at ordinary times and can be pushed out through manual operation, electric operation, flat pushing, rotation, folding and other methods. Compared with the A type USB interface, the built-in ultra-thin USB device of the mobile phone tablet computer is thin, beautiful, and easy to be widely applied, can enable a user to conveniently conduct charging or image-text, music and video transmission by enabling the USB device to be connected with a computer, a laptop, a mobile power and other devices.

The invention relates to a single-power-supply non-isolated adjustable constant-current source, which is used for solving the problems of increase in cost and waste of energy due to the adoption of a plurality of power supplies in an isolated output way in which an isolated power supply is adopted in the conventional current source. An input voltage value is selected through an adjusting unit, so that an output voltage can be changed; a central processor is used for outputting a digital signal according to a voltage value, and transmitting to a digital to analog conversion chip for converting into a voltage value; stabilizing circuit output is used for controlling an output current signal; an output current signal end is connected in series with a feedback resistor; the feedback resistor is a sampling unit; voltage processing of the feedback resistor is transmitted to a central processor, so that voltage change of a feedback end is captured by using the central processor under the condition that the voltage of an adjusting end is not changed; and a digital value output by the digital to analog conversion chip is adjusted, and an output voltage is adjusted, so that output current is constant. The single-power-supply non-isolated adjustable constant-current source is suitable for the fields of electronics, automation and the like.

The invention provides a voltage feedforward-based direct current voltage boosting converter control method. The control method comprises the following steps of detecting the input voltage, output voltage, input current and output current of the direct current voltage boosting converter; calculating the voltage feedforward duty ratio and calculating the current duty ratio by using a PI closed-loopalgorithm; judging whether the voltage feedforward duty ratio is less than a set maximum voltage duty ratio or not; if so, calculating the final duty ratio according to the current duty ratio and thevoltage feedforward duty ratio; and if not, calculating the final duty ratio according to the current duty ratio and the maximum voltage duty ratio, and controlling a power tube switch of the directcurrent voltage boosting converter based on the final duty ratio. The method has the advantages as follows: on the basis of the conventional current PI closed loop control direct current voltage boosting converter, voltage feedforward control is added, so that interference of fuel cell output voltage high fluctuation to the current PI closed loop control is suppressed, and the reaction speed of the direct current voltage boosting converter is increased.