21 results about "Undervoltage-lockout" patented technology

The invention discloses a programmable low-temperature-drift under-voltage locking circuit, and the circuit comprises a reference current generation module which is used for outputting an initial reference current, and the input end of the reference current generation module is connected with a first reference voltage; the zero-temperature-drift current source array is used for generating reference current according to the initial reference current and the second reference voltage and mirroring the reference current to a plurality of parallel branches; the trimming module is used for adjusting the total current of the parallel branches by using a programmable resistor and a capacitor; the sampling module is used for sampling the total current and the power supply voltage of the parallel branches output by the trimming module; and the comparison output module is used for comparing the power supply voltage with a sampling voltage generated according to the programmable resistor and the total current of the parallel branches, and outputting a pair of differential signals. Through the reference current generation module, the zero-temperature-drift current source array, the trimming module, the sampling network and the voltage comparator, the problems that in an existing resistance voltage division type undervoltage locking scheme, a threshold value is fixed and cannot be adjusted, and the scheme is sensitive to temperature changes are solved.

The invention provides a photovoltaic turn-off circuit and a photovoltaic system, the photovoltaic turn-off circuit is used for performing turn-off control on a photovoltaic module, the circuit comprises a photovoltaic turn-off module, an undervoltage locking module, a first resistor and a first switching tube, and when the input voltage of the photovoltaic module is smaller than a first threshold voltage, the undervoltage locking module is turned off. And the under-voltage locking module outputs a second driving voltage to the control end of the first switching tube to conduct the first switching tube. The resistance value of the first resistor represents the ratio of the first threshold voltage to the first working current, and the first working current represents the lowest working current of the photovoltaic turn-off module, so that the output voltage of the photovoltaic module is pulled down to be below the first threshold voltage by the first resistor; therefore, the photovoltaic turn-off module is ensured not to be restarted repeatedly due to weak light in the morning and evening. Meanwhile, the under-voltage locking module also outputs a second enable signal to the photovoltaic turn-off module when the input voltage of the photovoltaic module is smaller than the first threshold voltage, so as to stop the work of the photovoltaic turn-off module, thereby greatly reducing the power consumption of the photovoltaic turn-off module.

The invention discloses a self-adaptive control method and system for primary frequency modulation of a power grid, and relates to the technical field of power system automation and new energy grid-connected control, and the method comprises the following steps: when the energy storage residual electric quantity is within the range of 15%-25%, the energy storage output power is greater than 30% of the rated power, and the absolute value of the frequency deviation of the power grid is greater than 0.08 Hz, controlling the frequency of the power grid; the fixed virtual inertia is replaced with a two-dimensional matrix changing in real time along with the residual electric quantity and the direct current bus voltage, virtual capacitance current in the direction for preventing the direct current bus voltage from dropping is synchronously generated, and the magnitude of the virtual capacitance current is in direct proportion to the change rate of the direct current bus voltage; in the cliff interval with the energy storage residual electric quantity of 15%-25%, the phenomenon of undervoltage locking at the moment of primary frequency modulation high-power discharge caused by fixed virtual inertia is thoroughly eliminated, the frequency secondary collapse probability is reduced to zero, and no hardware is added.

The invention discloses an under-voltage locking circuit for chip power-on monitoring. The under-voltage locking circuit comprises a voltage sampling module, a single-input comparator and an output-stage three-stage structure, the voltage sampling module samples power supply voltage in proportion and directly serves as an input signal of the single-input comparator; the single-input comparator is of a two-stage structure, compares an input signal of the single-input comparator with a set threshold voltage, and outputs an output signal; and the output stage consists of a Schmitt trigger and a two-stage inverter, and is used for controlling a core circuit of the system according to the received output signal. From the aspect of structure, the structure does not need reference voltage or reference current, and the failure of the under-voltage locking circuit caused by slow response of the reference circuit can be avoided. And the reliability of the under-voltage locking circuit is greatly improved.

This application discloses a self-powered switch driver circuit and driving system, relating to the field of switching power supplies. The self-powered switch driver circuit includes: an undervoltage lockout circuit, a constant current drive circuit, a self-powered circuit, a current detection circuit, a first switching transistor, a second switching transistor, and a third switching transistor. The undervoltage lockout circuit includes a first comparator; the first comparator outputs a drive signal based on the power supply voltage and a reference voltage to adjust the on / off state of the third switching transistor, thereby adjusting the operating state of the constant current drive circuit. The current detection circuit acquires a current sampling signal and transmits it to the constant current drive circuit. The constant current drive circuit includes a bias circuit; based on the bias circuit, the constant current drive circuit outputs an adjustment signal according to the current sampling signal to adjust the operating states of the self-powered circuit, the first switching transistor, and the second switching transistor. This application aims to simplify the circuit structure, reduce manufacturing costs, and improve circuit reliability.

The embodiment of the invention discloses a battery charging method and device, terminal equipment and a storage medium, and is used for carrying out first-stage charging under the condition that a memory identification bit indicates that a battery state corresponding to the last shutdown of the terminal equipment contains undervoltage locking, and the first-stage charging is used for preventing undervoltage locking. In addition, second-stage charging needs to be carried out, redundant electric quantity is guaranteed to be supplied to power consumption when the terminal equipment is restarted, and therefore the probability of repeated starting is reduced. The method provided by the embodiment of the invention comprises the following steps: in response to a startup operation on the terminal equipment, acquiring a memory identification bit; under the condition that the memory identification bit indicates that the battery state corresponding to the last shutdown of the terminal equipment contains undervoltage locking, first-stage charging is executed; under the condition that it is detected that the first battery voltage of the first-stage charging meets a first target voltage threshold value, second-stage charging is executed; wherein the first target voltage threshold value is greater than a startup voltage threshold value of the terminal equipment.

A DC soft-start system for bus capacitors, relating to the field of power electronics technology, enables soft-start charging of bus capacitors. The system includes a drive-on subsystem, a drive-off subsystem, and a bus capacitor soft-start circuit. The drive-on subsystem includes a drive-on energy supply unit, a drive-on unit, and a drive undervoltage lockout unit. The bus capacitor soft-start circuit is used to charge the bus capacitor. The bus capacitor soft-start circuit includes a power switch and a bus capacitor. The power switch is used to control the charging of the bus capacitor. The drive-off subsystem is used to drive the power switch to turn off. The drive-on energy supply unit provides drive voltage and current to the drive terminal of the power switch. The drive-on unit transmits the drive voltage to the drive undervoltage lockout unit. The drive undervoltage lockout unit disconnects the power switch when the drive voltage is insufficient.

The invention discloses a control circuit using an H-bridge chip to drive a disengagement mechanism, comprising an MCU chip and an H-bridge chip, the H-bridge chip is connected between the MCU chip and the disengagement mechanism, the H-bridge chip comprises a switch tube Q1, a switch tube Q2, a switch tube Q3 and a switch tube Q4, and the switch tube Q1, the switch tube Q2, the switch tube Q3 and the switch tube Q4 are connected with the H-bridge chip. The source electrode of the switch tube Q1 is electrically connected with the drain electrode of the switch tube Q3, and the source electrode of the switch tube Q2 is electrically connected with the drain electrode of the switch tube Q4. According to the control circuit using the H-bridge chip to drive the disengagement mechanism, compared with the first scheme, the H-bridge chip is usually integrated with protection of overcurrent, overheating, undervoltage locking and the like, and the requirement for an external protection circuit is reduced; compared with a second scheme, a half-bridge circuit in an H bridge is used, a half-bridge MOS (Metal Oxide Semiconductor) has the characteristic of low gate-level charge Qg, high-frequency switching control of 100kHz at most can be supported, and the switching power consumption is low.

An undervoltage lockout (UVLO) circuit is provided. The UVLO circuit includes a first branch with a first transistor and a feedback transistor, and a second branch with a second transistor. Herein, source electrodes of the first transistor and the second transistor are electrically coupled to an input voltage, a gate electrode and a drain electrode of the first transistor and a gate electrode of the second transistor are electrically coupled to a source electrode of the feedback transistor, and a drain electrode of the second transistor is electrically coupled to a gate electrode of the feedback transistor. In response to the input voltage being below a threshold value, the feedback transistor is turned off. In response to the input voltage being above the threshold value, the feedback transistor is turned on and a voltage at the gate electrode of the feedback transistor becomes a constant voltage value.

A bus capacitor DC soft start system relates to the technical field of power electronics and can realize charging soft start of a bus capacitor. The system comprises a drive switch-on subsystem, a drive switch-off subsystem and a bus capacitor soft start loop. The driving opening subsystem comprises a driving opening energy supply unit, a driving opening unit and a driving undervoltage locking unit. And the bus capacitor soft starting loop is used for charging the bus capacitor. The bus capacitor soft starting loop comprises a power switch tube and a bus capacitor. The power switch tube is used for controlling charging of the bus capacitor. And the driving closing subsystem is used for driving the power switch tube to be closed. And the driving turn-on energy supply unit is used for providing driving voltage and current for the driving electrode of the power switch tube. And the driving opening unit is used for transmitting the driving voltage to the driving undervoltage locking unit. And the driving undervoltage locking unit is used for disconnecting the power switch tube when the driving voltage of the power switch tube is insufficient.

This invention discloses a low-voltage, high-load start-up linear current limiting circuit for a DC-DC converter, comprising: a first current mirror circuit and one end of a resistor R3 are grounded together; the other end of resistor R3 is connected to a second current mirror circuit and a second current source; the second current mirror circuit, the differential pair circuit, the second current source, the source of MOSFET M5, and one end of the first current source are all externally connected to an input voltage VDD; the other end of the first current source is connected to the first current mirror circuit; the gate and drain of MOSFET M5 are connected to the differential pair circuit; the first current mirror circuit is connected to the differential pair circuit, and the differential pair circuit is connected to the second differential pair circuit; the differential pair circuit is externally connected to an undervoltage threshold V. UVLO This invention compares the input voltage with an undervoltage threshold to generate a current value that changes linearly with the input voltage, thereby changing the current-limiting voltage and linearly adjusting the current-limiting value. This avoids the problem of the input voltage being pulled down during a high-current start-up with a low-voltage input, triggering undervoltage lockout and causing start-up failure or repeated start-ups, and can maximize the start-up speed.

According to the under-voltage locking protection circuit based on the bootstrap circuit, the detection voltage of a BOOST-SW is determined by a divider resistor, an NPN triode is introduced, a comparison threshold value is converted into a band-gap reference voltage BG from the threshold voltage of an MOS tube, and the deviation of the detection voltage along with the temperature is reduced by controlling the band-gap reference voltage BG within a reasonable range. According to the other scheme, the detection voltage of the BOOST-SW is determined by a divider resistor, the zero-temperature coefficient current and the resistor are used for generating reference threshold voltage, the current is trimmed in a low-voltage domain, and the reference voltage is trimmed. According to the invention, a brand new detection circuit structure is adopted, and the structure can optimize the detection threshold value, so that the detection threshold value is insensitive to a process corner and temperature, the consistency of the overturning threshold value is better, the precision of the monitoring threshold value is improved, and the variation range of the monitoring threshold value is reduced at the same time.

Embodiments of the present disclosure provide an under-voltage lockout circuit, which comprises a voltage sampling circuit, a comparison circuit, and a hysteresis control circuit. The voltage sampling circuit samples a voltage under test and provides a sampled voltage to the comparison circuit via a first node. The sampled voltage is obtained by dividing the voltage under test with at least two transistors. The comparison circuit compares the sampled voltage with a reference voltage from a reference voltage terminal and generates an under-voltage lockout indication signal based on the comparison result. An active level of the under-voltage lockout indication signal is used to indicate that a circuit using the voltage under test enters an under-voltage lockout state. The hysteresis control circuit causes the under-voltage lockout indication signal to flip from an inactive level to the active level when the voltage under test rises to a first preset voltage value, and causes the under-voltage lockout indication signal to flip from the active level to the inactive level when the voltage under test falls from the first preset voltage value to a second preset voltage value. The first preset voltage value is higher than the second preset voltage value.

This invention relates to a small, passive IoT development board with energy management functionality. It comprises an IoT component, an energy management circuit, and an energy harvesting component. The energy harvested by the energy harvesting component powers the IoT component via the energy management circuit. Recognizing the current scarcity of practical passive IoT development boards, this invention integrates an energy management circuit with rectification, undervoltage lockout, adjustable threshold voltage, extremely low leakage current, and regulated output with a low-power SOC (System-on-Chip) minimum system capable of wireless networking communication such as Bluetooth, Wi-Fi, and Zigbee. This results in a compact, easily miniaturized, and mass-producible passive IoT development board. Users can adjust the energy management circuit and write specific Bluetooth communication commands according to their specific scenarios, thereby efficiently and reliably completing the entire passive IoT development process.

The application discloses a kind of bipolar under-voltage lockout protection circuits, including resistance proportional current mirror and starting circuit, resistance proportional current mirror includes LPNP1 tube, LPNP2 tube and LPNP3 tube, LPNP1 tube emitter is connected with power supply Vcc by resistance R1, LPNP2 tube emitter is connected with power supply Vcc by resistance R2;LPNP2 tube and LPNP3 tube common base, LPNP2 tube collector LPNP3 tube emitter connection, LPNP3 collector is connected with ground by resistance R3;LPNP2 tube collector is connected with bias circuit and current source;bias circuit and current source are respectively connected with the collector and base of darlington tube, the emitter of darlington tube is connected with the first end of resistance R9, and the second end of R9 is connected with the collector of NPN19 tube, the base of NPN19 tube is connected with the collector, and the emitter is grounded;With the characteristics of simple process, low power consumption, threshold voltage high precision, high reliability.

A closed loop control system actively regulates the battery current paths of physically separated circuits so that the current is approximately the same for each of the circuits regardless of the various system loads. The closed loop control system modulates the current paths by either modulating a high side transistor used to independently limit each battery's current path or by modulating a DC / DC converter's output voltage to independently boost each battery's current path. The closed loop control system is also designed to handle undervoltage lockout (UVLO) situations when one of the batteries is nearing empty to tilt the power balance in the chance that there is an existing battery charge mismatch to support system load bursts and to turn off the circuit when the system current draw is exceptionally low. A tilting circuit also identifies and discharges the battery with the higher charge until the charge states are substantially equal.

A disclosed apparatus may extend hold-up times for computing devices with redundant power supply units (PSUs). For example, an apparatus may include a plurality of PSUs and a controller. In one example, the PSUs may be configured to convert power from at least one AC input into a direct current (DC) output and to provide the DC output to a computing device. In this example, the controller may be configured to detect a loss of the AC input and a failure of a first PSU included in the plurality of PSUs. The controller may also be configured to extend a hold-up time of a second PSU included in the plurality of PSUs by boosting an undervoltage lockout signal monitored by the computing device in response to detecting the loss of the AC input and the failure of the first PSU. Various other apparatuses, systems, and methods are also disclosed.

This application relates to the fields of smart home and wireless power transmission technology, and discloses a method for multi-device power sharing and robot scheduling optimization for smart homes. The method includes: a terminal device calculating a service interruption risk index based on the estimated peak current of the service task and the DC internal resistance of the power supply battery; when the risk index exceeds a safety threshold and the task is latency-tolerant, the task is suspended and external power is requested; otherwise, a degraded parameter set is invoked for operation. A server schedules a mobile robot to the target area based on a global energy efficiency topology. The mobile robot performs fine-tuning alignment using the reflected impedance gradient and provides accompanying power to the terminal device through a magnetic coupling channel, while simultaneously monitoring changes in the transmitter's input impedance to identify the task completion status. This invention solves the undervoltage lockout problem in battery aging scenarios through proactive risk prediction and multi-modal handling strategies, and achieves high-precision physical alignment and non-intrusive power supply control without visual assistance.

A zero-temperature-coefficient low-voltage undervoltage lockout circuit is characterized by comprising a voltage divider unit, a comparator unit, a feedback unit, and an output unit. The voltage divider unit generates a voltage divider of the input voltage. The comparator unit, connected to both the voltage divider unit and the output unit, generates a reference voltage based on the voltage divider and outputs the reference voltage to the output unit. The feedback unit feeds back the positive temperature coefficient current generated by the comparator unit to the voltage divider unit to counteract the negative temperature coefficient of the transistor voltage in the comparator unit. The output unit determines an output undervoltage lockout signal based on the zero-temperature-coefficient reference voltage. This invention is simple, requires few components, and significantly reduces the input voltage amplitude requirements of the undervoltage lockout circuit, allowing the undervoltage lockout signal to flip at a relatively small reference voltage, thus achieving undervoltage protection.

The present invention discloses an undervoltage lockout circuit, including a resistor R2 and a Zener diode D3. One end of the resistor R2 is connected to a high-voltage power supply VDD, one end of the resistor R1, the drain of a switch NM1, and the drain of a switch NM2. The other end of the resistor R2 is connected to the cathode of the Zener diode D3, the gate of the switch NM1, and the gate of the switch NM2. The other end of the resistor R1 is connected to the cathode of the Zener diode D1. The source of the switch NM1 is connected to one end of the resistor R5. The source of the switch NM2 is connected to one end of the resistor R6. The other end of the resistor R6 is connected to an undervoltage lockout signal VDDON_N, the drain of the switch NM10, and the gate of the switch NM4. The undervoltage lockout circuit of the present invention is simple to implement and has few process limitations.

The utility model relates to the technical field of power supply modules, and discloses a non-isolated DC / DC power supply module, which comprises an input voltage pin VIN, the input voltage pin VIN is connected with a power supply for a converter, a capacitor is connected between the input voltage pin VIN and an output voltage pin VOUT, a module ground GND is connected with a frequency setting pin RFREQ, and the frequency setting pin RFREQ is connected with the converter. The output voltage pin VOUT is connected with the normal output indication pin PGOOD in the module, the output voltage pin VOUT is connected with the feedback pin FB, and the resistor RFB is connected between the output voltage pin VOUT and the feedback pin FB, so that stable output voltage is provided through effective application of the module; the power supply has multiple protection characteristics such as over-current protection, short-circuit protection, under-voltage protection, input under-voltage locking protection, over-temperature turn-off protection and the like, remote enabling control can be realized by using an EN pin, a PGOOD pin can provide normal output indication of a power supply, and an FB pin can flexibly adjust output voltage.