11408 results about "Overvoltage" patented technology

An overvoltage output protector is electrically connected to a constant-voltage switching power supply which includes a switching transistor converting a DC voltage obtained by smoothing an AC voltage supplied from an AC power source into a cyclic pulse signal. In the overvoltage output protector, an overvoltage monitor whether a potential of the cyclic pulse signal is a predetermined value or more. A deactivator turns off the switching transistor in a case where the overvoltage monitor judges that the potential of the cyclic pulse signal is the predetermined value or more.

A patient-worn energy delivery apparatus for imparting electrical therapy to the body of a patient responsive to an occurrence of a treatable condition includes a voltage converter for converting electrical energy from an initial voltage to a final voltage, and a defibrillator electrically coupled between the converter and the patient and having an energy reservoir for receiving the electrical energy. The defibrillator produces preshaped electrical pulses such as defibrillation pulses and cardioversion pulses. The apparatus additionally includes an energy delivery controller electrically coupled to the patient and the converter and the defibrillator. The controller causes the converter to provide the electrical energy to the defibrillator at a specific charging rate in response to an energy level in the reservoir. The apparatus may include a plurality of electrodes interposed between the defibrillator and the patient and each electrode preferably has an impedance reducing means contained therein. One embodiment of the apparatus may include a H-bridge to produce a positive-going pulse segment and the negative-going pulse segment within the biphasic exponential signals. The apparatus periodically measures the energy as it is being delivered to the patient and can pre-emptively stop or truncate the pulse in the event an error condition is detected, such as an overvoltage condition or if the energy level approaches a predetermined level. The electrical components which store and release the energy minimize the size and expense of the apparatus, while isolating the microcomputer from the high energy levels as the therapeutic pulse is delivered.

The invention relates to a photovoltaic cell -DC / DC boost conversion charge method which belongs to battery technique field. The method includes: 1) a portable equipment accumulator voltage is detected by a voltage sensor, when lows to full charge capacity, the voltage sensor makes DC / DC boost converter starting DC / DC conversion, and electricity quantity flows from photovoltaic current to lithium battery for charging; 2) when the portable equipment accumulator is in full charge capacity state, accumulator need not charge again, the voltage sensor makes DC / DC boost converter forbidding DC / DC conversion, thereby, the portable equipment accumulator is protected and over charge phenomena is prevented. The method can be realized simply, and has short reaction time, high efficiency, overvoltage protection and anti-counterblast protection.

The invention relates to an LED driving power supply control circuit. The LED driving power supply control circuit comprises an EMI filter and rectifier module, a DC-DC isolation constant current driver module, an input under-voltage lag protection module, and an output current protection module, wherein the EMI filter and rectifier module is used for performing EMI filter and full-wave rectification on an alternating-current voltage input by a power supply to generate a direct-current voltage; the DC-DC isolation constant current driver module is used for processing the direct-current voltage so as to generate a constant output current for the work of the LED power supply; the input under-voltage lag protection module is used for clamping and splitting the direct-current voltage so as togenerate an enable signal and controlling the DC-DC isolation constant current driver module to start or not to start according to the enable signal; and the output current protection module is used for detecting the constant output current and controlling the DC-DC isolation constant current driver module to stop generating the output current while the constant output current exceeds a current threshold. The invention also relates to an LED lamp. The LED driving power supply control circuit and the LED lamp realize the alternating-current inputting and constant-current outputting in a wide range and have the input clamping lag protection and the output overvoltage protection functions.

A power management system and method for multiple redundant power supplies. The present invention provides management and control of N+M power supplies, where N represents the minimum number of power supplies required and where M is the number of redundant power supplies (M>1), where any one of the power supplies may be capable of supplying power to all the loads of the power subsystems. In the preferred embodiment each power subsystem includes a power supply and a controller coupled to a power bus. A communication bus is provided common to each power subsystem. During reset or power-on periods, the controllers are programmed to uniquely delay the start time of each power supply, thereby protecting against an overcurrent / overvoltage condition on the power bus during reset periods. A master controller is provided to monitor normal operating conditions of the power subsystems and communication bus. The master controller is programmed to ensure that a predetermined number of power supplies are coupled to the power bus, even in the event of total or partial communication failure.

A transfer gate or pass gate circuit for transferring logic signals between nodes for a range of available high-potential supply levels. The primary transfer gate is designed to protect against potentials that either exceed either a high-potential or a low-potential level or that undershoot such potential levels. For overshoot (overvoltage) tolerance, this is achieved by coupling a NMOS transistor in parallel with a pair of PMOS transistors that are coupled in series. All three transistors are located between two nodes, either of which can be the input or the output of the transfer gate. The NMOS transistor is designed to be larger than the PMOS transistors and carries most of the transfer capability. The smaller PMOS transistors are designed to eliminate potential drops that would otherwise occur with a single NMOS transistor or with a complementary pair of transistors. For undershoot (undervoltage) tolerance, a PMOS transistor is coupled in parallel with a pair of NMOS transistors that are coupled in series.

To avoid burning out a capacitor in a synchronous rectification type DC-to-DC converter due to overvoltages, the synchronous rectification type DC-to-DC converter includes a storage unit storing therein power derived from a power supply, switching elements connecting and disconnecting respective signal paths from power and ground, and a control unit controlling the connecting / disconnecting operations of the switching elements to maintain a voltage output from the storage unit at a predetermined value. The DC / DC converter also includes an overvoltage detecting unit monitoring a voltage derived from the power supply to thereby output an alarm signal when the voltage derived from the power supply exceeds a preselected voltage value, a shortcircuiting unit influencing the connecting conditions of the switching elements when the alarm signal from the overvoltage detecting unit is input therein, whereby the voltage derived from the power supply is shortcircuited, and an interrupting unit interrupting one of the signal paths by the power shortcircuited by the shortcircuiting unit.

A charging method includes a constant-current charging step wherein a constant charge current is supplied to a secondary battery to be charged to a predetermined end voltage; and a constant-voltage charging step wherein the predetermined end voltage is maintained by reducing the charge current after said secondary battery is charged to the end voltage, wherein: said constant-current charging step includes the charging step to be carried out with the end voltage set to OCV which is a voltage when no current is flowing, and with a voltage of a charge terminal of said battery pack set to an overvoltage above said OCV, and said constant-voltage charging step includes the step of reducing the voltage across the charge terminals to the after the voltage across the charge terminals is increased to the overvoltage or after the charge current of the charge terminal is reduced to or below a predetermined current level.

The invention provides a low current grounding single phase earth fault diagnosis method, comprising: capturing A voltage to ground, B voltage to ground, C voltage to ground, neutral point current and entire waveform information of each zero sequence current from a steady state to a transient state then to steady state when neutral point voltage exceeds presupposed threshold; first diagnosing whether being single phase earth fault, PT fusing, ferro resonance, arc suppressing coil resonance overvoltage, or neutral point overvoltage disturbance caused by experiment; selecting lines for the earth fault. The inventive method makes full use of steady state information and transient information of electric network before and after fault, and judges the fault and selects lines according to the long term changing rule of the neutral point voltage, which is different from the traditional stable state line selecting method and the transient line selecting method, thereby being suitable for the neutral point unearth electric network and the neutral point arc suppressing coil earth electric network at the same time, and well adapts the condition of complex site, thereby ensuring fault diagnosis and correct line selection.

A protection method may prevent a load-mismatch-induced failure in solid-state power amplifiers. In an RF power amplifier, the load voltage standing-wave ratio results in very high voltage peaks at the collector of the final stage and may eventually lead to permanent failure of the power transistor due to avalanche breakdown. The method avoids breakdown by attenuating the input power to the final stage during overvoltage conditions, thus limiting the output collector swing. This is accomplished by a feedback control system, which detects the peak voltage at the output collector node and clamps its value to a given threshold by varying the circuit gain. Indeed, the control loop is unlocked in the nominal condition and it acts when an output mismatching condition is detected. A control circuit also allows a supply-independent collector-clamping threshold to be accurately set.

The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing / blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.

An overvoltage / overcurrent electrostatic discharge protection single circuit structure for Integrated Circuits protects on all paths and polarities between In / Out, Supply, and Ground pins. The structure is built on the chip substrate with an N well with three P Diffusions therein each containing N+ and P+ diffusions therein to form 6 transistors and 8 parasitic resistors to yield 5 thyristors. The structure provides very fast, symmetrical, full protection while using minimal chip area.

The present invention provides overvoltage circuit protection. Specifically, the present invention provides a voltage variable material (“VVM”) that includes an insulative binder that is formulated to intrinsically adhere to conductive and nonconductive surfaces. The binder and thus the VVM is self-curable and may be applied to an application in the form of an ink, which dries in a final form for use. The binder eliminates the need to place the VVM in a separate device or for separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid (FR-4) laminate, a polyimide or a polymer. The VVM can also be directly applied to different types of substrates that are placed inside a device.

Methods and apparatus for controlling switching in a DC-to-AC inverter to prevent overvoltages applied to an AC motor by determining the switching order of the phase voltage signals, providing gating signals at switching intervals by modulating a carrier wave with the phase voltage signals, comparing the switching intervals to a predetermined minimum time interval sufficient for reflected wave transients to dissipate, and adjusting the switching intervals to be at least equal to the predetermined minimum time interval.

The power IC includes an output transistor M0 which controls a current flowing into an L load, a dynamic clamp circuit which clamps an overvoltage, and a clamp control circuit which controls the operation of the dynamic clamp circuit. The clamp control circuit activates the dynamic clamp circuit, which is normally inactive, upon detection of a back EMF by the L load.

A suppression and protection circuit is used in conjunction with a circuit interrupter. In one configuration, a voltage clamping device such as a metal oxide varistor is utilized in a ground fault circuit interrupter product for handling transient surges and overvoltage conditions and is placed in series with a solenoid coil. The suppression and protection circuit includes a crowbar device across the line such as a header spark gap to prevent overvoltages, and a low pass filter such as an LC filter for suppressing transient surges.

A power factor correction circuit using a first rectifier diode to control the series charging of two capacitors and two rectifier diodes to control the parallel discharging of the two capacitors. The power factor correction circuit further includes a resistor that is series-connected with the first diode to improve the power factor and to reduce the current drawn when the voltage is turned on. The rectifier diodes are advantageously voltage limiting diodes to protect the downline circuitry against overvoltages. In one improvement, a current-controlled electronic switch is used for protection against overvoltages that are just above the peak value of the line voltage.

Disclosed is an output overvoltage protection circuit for a power amplifier having a plurality of stages, which comprises a monitor circuit for monitoring an output overvoltage of an output transistor in the final stage of the power amplifier and allowing a current to flow therethrough in response to the monitored output overvoltage, and a current mirror circuit for supplying a current proportional to the current from the monitor circuit in such a manner that the base bias of the first-stage transistor of the power amplifier is reduced in response to the current supplied from the current mirror circuit, to reduce the output of the final-stage output transistor.

A power supply system and power overvoltage safety protection control method, the power supply system comprises an AC / DC switching power supply, a spare battery and at least one DC / DC transformer, and further comprises an overvoltage detection unit which is used for detecting the output voltage of each DC / DC transformer in real time, comparing the output voltage of the DC / DC transformer with a reference voltage and outputting a fault signal. When detecting a dangerous voltage at a later stage output, the system firstly clamps and absorbs a transient dangerous voltage, uses the overvoltage detection unit to detect an overvoltage fault signal synchronously, cuts off the power supply to each transformer from the AC / DC switching power supply and the spare battery, and directly turns off a control chip after converting the fault signal into a proper voltage, thereby realizing the tertiary protection of the system, avoiding the safety risk possibly resulted from the input and output short circuit of the transformer, and improving the reliability of the system.

Disclosed is a variable voltage protection device for electronic devices which in one aspect comprises a thin layer of neat dielectric polymer or glass positioned between a ground plane and an electrical conductor for overvoltage protection, wherein the neat polymer or glass layer does not include the presence of conductive or semiconductive particles. Also disclosed is the combination of the neat dielectric polymer or glass thin layer positioned on a conventional variable voltage protection material comprising a binder containing conductive or semiconductive particles. A multi-layer variable voltage protection component is disclosed comprising three layers of overvoltage protection material wherein the outer two layers contain a lower percentage of conductive or semiconductive particles and wherein the inner layer contains a higher percentage of conductive or semiconductive particles. The multi-layer component can optionally be used in combination with the neat dielectric polymer or glass layer and can optionally have interposed metal layers. A method is disclosed for dispersing insulative particles and conductive or semiconductive particles in a binder using a volatile solvent for dispersement of the insulative particles and the conductive or semiconductive particles before mixing with the binder.

A hybrid air-gap / solid-state device protection device (PD) for use in an electrical power distribution system includes an air-gap disconnect unit connected in series with a solid-state device, a sense and drive circuit, and a microcontroller. Upon the sense and drive circuit detecting an impending fault or exceedingly high and unacceptable overvoltage condition in the PD's load circuit, the sense and drive circuit generates a gating signal that quickly switches the solid-state device OFF. Meanwhile, the microcontroller generates a disconnect pulse for the air-gap disconnect unit, which responds by forming an air gap in the load circuit. Together, the switched-OFF solid-state device and air gap protect the load and associated load circuit from being damaged. They also serve to electrically and physically isolate the source of the fault or overload condition from the remainder of the electrical power distribution system.

The invention discloses a pot cover, an electric pressure cooker and an anti-overflow control method. The pot cover comprises a cover body, an exhaust valve core mounted in the cover body, an exhaustvalve body sleeving the upper end of the exhaust valve core, and a hot gas sensing device; a cavity communicating with the outside is disposed in the cover body; ; an exhaust passage extending in an axial direction of the exhaust valve core is disposed in the exhaust valve core; an exhaust hole is formed in the upper end of the exhaust valve core, and an intake hole is formed in the lower end of the exhaust valve core; the hot gas sensing device is disposed in the cavity, is used for sensing hot gas discharged from the exhaust hole, and outputting an overvoltage signal to a control circuit board when the hot gas is sensed so as to adjust a heating program. A trace amount of hot gas discharged from the exhaust hole is sensed timely by the hot gas sensing device, the overvoltage signal is output to the control circuit board, the control circuit can timely adjust the heating program to reduce the pressure of the cooker, and the anti-overflow effect can be achieved.

The invention belongs to the technical field of charging and provides a terminal, and a battery charging control device and method. The battery charging control device comprising a battery connector, a master control module and a rapid charging switch module is adopted, in the process of carrying out conventional charging or quick charging on a battery in the terminal, data communication is carried out between the master control module and an external power adapter through a communication interface of the terminal, and the charging voltage and the charging current of the battery are obtained. If the charging voltage is larger than the voltage threshold value and / or the charging current is larger than the current threshold value, the master control module sends a charging cut-off instruction to enable a controller of the terminal to shut down the communication interface of the terminal, so the purpose of overvoltage and / or overcurrent protection on the battery is achieved.

Electrical fire risks and consumer safety are major concerns driving regulators worldwide to implement more stringent electrical code and enforcement. While there are many commercially available protective devices available, none affords total protection, and they are made and classified only to protect circuits from specific or limited number of faults.This invention is about an apparatus, system and method for protection of electrical circuits and consumers from literally all known electrical faults in Direct Current (DC) and Alternating Current (AC) single and multi-phase systems such as and including Arc Faults, Ground and Leakage Faults, Surge, Overload, Short Circuit, Glowing Connections, Miswired Connections, overvoltage, undervoltage and Phase-Loss. Said apparatus, system and method come in the form of or in a housing as a Circuit Breaker, Receptacle, Convenience Outlet, Attachment Plug, Equipment Controller, a circuit, or a system integrated with another system, device or apparatus.

A remotely mountable weatherproof bi-directional, half-duplex switching amplifier system is designed to provide maximum range for low power half-duplex radios such as Spread Spectrum radio transceivers. This invention automatically senses when to go into the transmitter amplification mode and puts all the transmit power right at the antenna. In the receive mode, it provides low noise pre amplification of received signals at the antenna thereby minimizing or even eliminating the effects of the coaxial transmission line from the radio transceiver to the remote location of the antenna. The invention is preferred to be in a waterproof enclosure adjacent to the antenna mounted to a pole and powered by a DC injector and excited by a transceiver, both pole and injector located remote from the mounting pole and also includes an improved electrostatic overvoltage protection device.

The invention is suitable for the field of overvoltage protection, and provides an input overvoltage protection circuit and a direct current-direct current (DC-DC) power supply conversion device. The input overvoltage protection circuit comprises a voltage detection circuit, a drive and delay circuit, an output circuit and a switching circuit which are connected in turn, wherein the voltage detection circuit detects input voltage, compares the detected voltage with set reference voltage and outputs a corresponding voltage signal according to a comparison result; the output circuit outputs a switching control signal according to a drive and delay signal output by the drive and delay circuit and controls the switching on and off of the switching circuit; the output end of the switching circuit is connected with a load; and when overvoltage is input, the switching circuit is switched off, and the load is isolated from the input voltage. In the input overvoltage protection circuit, the voltage detection circuit detects the input voltage, and the load is isolated from and disconnected with the input voltage through the switching circuit when the input voltage is higher than the set reference voltage, so that the load is prevented from being damaged.