Abstract: A semiconductor module including a first switching device coupled to a first line, a terminal, at which a first voltage corresponding to a first current flowing through the first switching device is generated, coupled to the first switching device, a second switching device coupled to the first line for allowing a second current corresponding to the first current to flow therethrough, a voltage generation circuit configured to apply, to a second line, a second voltage lower than a power supply voltage, a resistor, across which a third voltage corresponding to the second current is generated, coupled between the second switching device and the terminal, a reference voltage circuit coupled to the terminal for generating a fourth voltage, and a comparator circuit coupled between the first and second lines, for determining whether the first switching device is in an overcurrent state based on a comparison between the third and fourth voltages.

Abstract: An apparatus comprises a solid state device and a switch in series with the solid state device. The apparatus comprises a leak detection component connected to the solid state device. The apparatus comprises a gate driver configured to drive a gate of the solid state device. The gate driver comprises test circuitry configured to apply a test voltage to the gate of the solid state device. The test voltage is less than a threshold voltage of the solid state device. The leak detection component is configured to detect a leakage of the solid state device.

Abstract: An apparatus for detecting an open neutral condition in a split phase power system is described. The apparatus includes two powered lines providing output electricity to an electrical distribution system and a shared neutral line providing a grounded neutral to the first and second powered lines. The apparatus is configured for detecting when an open neutral condition is present in the split phase power system by determining when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and in response to detecting that the open neutral condition is present, causing an interrupter to interrupt the power supplied by the first and second powered lines or to generate a signal indicating an open condition.

Abstract: In leakage detection device, coupling capacitor has a first end connected to a current path of power storage unit connected to load in a state of being insulated from a ground. Voltage output unit generates a periodic voltage that changes periodically, and applies the periodic voltage to a second end of coupling capacitor via impedance element. Voltage output unit measures a voltage at a node between coupling capacitor and impedance element. Leakage determination unit estimates at least one of an upper peak value and a lower peak value at a certain time, calculates a peak-to-peak value between the upper peak value and the lower peak value with virtually aligned time axes, and determines presence or absence of a leakage between a current path of power storage unit and the ground.

Abstract: Systems, methods, and apparatuses for measuring capacitance of a load. An apparatus includes a ground connector, an output connector configured to couple to the load, and a time-varying signal source configured to inject a time-varying voltage signal onto a conduction path between the ground connector and the output connector. A DC power source is configured to apply a DC offset to the time-varying voltage signal, and a current monitor is configured to measure time-varying current in the conduction path. A capacitance module is configured to determine the capacitance based upon at least one of the time-varying current and a frequency of the time-varying voltage signal.

Abstract: In leakage detection device, coupling capacitor has a first end connected to a current path of power storage unit connected to load in a state of being insulated from a ground. Voltage output unit generates a periodic voltage that changes periodically, and applies the periodic voltage to a second end of coupling capacitor via impedance element. Voltage output unit measures a voltage at a node between coupling capacitor and impedance element. Leakage determination unit estimates at least one of an upper peak value and a lower peak value at a certain time, calculates a peak-to-peak value between the upper peak value and the lower peak value with virtually aligned time axes, and determines presence or absence of a leakage between a current path of power storage unit and the ground.

Abstract: In leakage detection device, coupling capacitor has a first end connected to a current path of power storage unit connected to load in a state of being insulated from a ground. Voltage output unit generates a periodic voltage that changes periodically, and applies the periodic voltage to a second end of coupling capacitor via impedance element. Voltage output unit measures a voltage at a node between coupling capacitor and impedance element. Leakage determination unit estimates at least one of an upper peak value and a lower peak value at a certain time, calculates a peak-to-peak value between the upper peak value and the lower peak value with virtually aligned time axes, and determines presence or absence of a leakage between a current path of power storage unit and the ground.

Abstract: An earth leakage detecting device comprises following elements. A first end of coupling capacitor is connected to a current path of power storage connected to load in a state of being insulated from a ground. Voltage output unit generates a periodic voltage that changes periodically, and applies the periodic voltage to a second end of coupling capacitor via impedance element. Voltage measurer measures a voltage at a connection point between coupling capacitor and impedance element. Earth leakage determiner determines presence or absence of an earth leakage between the current path of power storage and the ground on the basis of the measured voltage. Voltage output unit has a preparation period for constantly outputting a potential between a high-side potential and a low-side potential of the periodic voltage before a measurement period for outputting the periodic voltage.

Abstract: A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

Abstract: An apparatus for detecting an open neutral condition in a split phase power system is described. The apparatus includes two powered lines providing output electricity to an electrical distribution system and a shared neutral line providing a grounded neutral to the first and second powered lines. The apparatus is configured for detecting when an open neutral condition is present in the split phase power system by determining when a power current is present on one or both of the first and second powered lines while a return current is not present on the neutral line; and in response to detecting that the open neutral condition is present, causing an interrupter to interrupt the power supplied by the first and second powered lines or to generate a signal indicating an open condition.

Abstract: An environment detecting module, for securing a shell of a server, includes a sensing module, configured to sense an environment status by a polling method and generate a sensing signal according to the environment status; a connection module, configured to electrically connect the environment detecting module to a host terminal with a first connection status or a second connection status; and a microcontroller unit, coupled to the sensing module and the connection module, configured to determine a power source of the environment detecting module according to the first connection status or the second connection status, and to determine a first mode or a second mode of the environment detecting module according to the power source.

Abstract: A method for automatically testing a relay is provided. The method includes applying power to a testing device for automatically testing the relay, determining a position of a selector switch based on a user selection for testing, selectively energizing the relay based on the position of the selector switch, detecting, by a hardware processor, an energize status signal from the selector switch, testing, by the hardware processor and based at least on the energize status signal, a control coil or a contact of the relay to generate a test result, and displaying, using display, the energize status signal and the test result.

Abstract: A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

Abstract: The present invention is directed to protective wiring devices, and more particularly, to a protective wiring device that meets the prevailing electrical codes and is convenient for a homeowner to reset after it has tripped.

Abstract: A circuit breaker failure protection relay includes an input circuit to which an opening command from a first circuit breaker is input, and a circuit breaker failure detection element configured to compare a magnitude of a current detection signal in a power system with a setting value to make a determination about an overcurrent. The circuit breaker failure detection element is capable of changing the setting value to a first value and a second value that is larger than the first value according to a switching signal. The circuit breaker failure protection relay is configured to, when the opening command is input and when the circuit breaker failure detection element determines that an overcurrent occurs, output an opening command for the second circuit breaker in a neighborhood of the first circuit breaker.

Abstract: A method of determining a prospective short circuit current for an electrical system including a source includes connecting a test load between either: (i) a first phase line and a second phase line of the electrical system or (ii) the first phase line and the neutral line of the electrical system, employing a sensor coupled to the electrical system to measure a voltage drop across the test load, determining a voltage value based on at least the measured voltage drop across the test load, determining a total effective impedance for the first phase line to the source, and determining the prospective short circuit current based on the voltage value and the total effective impedance.

Abstract: A method and an apparatus for controlling a circuit breaker in an electrical energy supply network. A switching signal is generated by a protective or control device of the energy supply network and the switching signal is transmitted to a control unit of the circuit breaker. The control unit is caused to open the switching contacts of the circuit breaker upon reception of the switching signal. In order to ensure a switching operation which is as fast as possible even in those energy supply networks in which phases of the current to be switched by a circuit breaker which are free of zero crossings can occur, a current flowing through the circuit breaker is recorded and is checked for the occurrence of zero crossings. The transmission of the signal for opening the switching contacts is prevented until at least one zero crossing has been detected.

Abstract: A circuit breaker includes a tripping unit for interrupting an electrical circuit, and at least one current sensor for determining the electrical current flowing through the circuit breaker, connected to a control unit and configured such that the determined current is compared with current/period limit values. If a current/period limit value is exceeded, the tripping unit interrupts the electrical circuit. The current/period limit values include an adjustable first current limit value, present for a first period for an interruption; an adjustable second period, during which a second current limit value must be present to effect an interruption; and a range between the first current limit value and the second current limit value, the period decreasing with increasing current limit values in order to effect an interruption. The second current limit value can be adjusted at the circuit breaker.

Abstract: The present disclosure relates to a system for charging or maintaining a battery that includes power conversion circuitry configured to provide output power for charging or maintaining the battery. The system also includes electrical conductors coupled to the power conversion circuitry and configured to be coupled to the battery for charging or maintaining the battery. Additionally, the system includes control circuitry coupled to the power conversion circuitry and configured to monitor charging or maintaining of the battery. The control circuitry is further configured to determine whether the battery may be defective or failing based upon the output power and a time threshold.

Abstract: Aspects of the disclosure provide a terminal device that includes an antenna element and an interface component. The antenna element is mounted on a casing of the terminal device to transmit/receive electromagnetic waves. The interface component is configured to couple an external device with the terminal device for a wired transmission. The interface component includes a metal shell configured to have a fixed potential state to shield the wired transmission from noise when the interface component is active for the wired transmission, and to have a floating state to avoid affecting the antenna element for transmitting/receiving electromagnetic waves when the interface component is idle.

Abstract: Systems and methods for overvoltage protection are disclosed. According to one illustrative implementation, an overvoltage protection device is provided having one or more overvoltage protection elements and a measuring device for monitoring the overvoltage protection elements. Further, the measuring device may include an evaluation device, which is designed to count pulse-like overvoltage events which are arrested by the overvoltage protection element, wherein the evaluation device is connected to the overvoltage protection element via a light-measuring device and/or a device for identifying a current flow.

Abstract: A current switch self-calibrates when a reset control is actuated and displays an expected current in the monitored conductor, one or more trip points of the current switch and the last known current in the monitored conductor.

Abstract: A circuit protection device includes an adjustment device configured to provide a selected voltage, a memory configured to store a selector, and a processor coupled to the memory and to the adjustment device. The processor is configured to receive the selector from the memory, select an operational parameter of the circuit protection device based on the selector, receive a voltage value representative of a selected voltage provided by the adjustment device, and set the selected operational parameter to a parameter value based on the voltage value received.

Abstract: An overcurrent relay and a molded case circuit breaker (MCCB) including the same are provided. The MCCB includes: a switching mechanism unit; an overcurrent relay; a trip mechanism, wherein the overcurrent relay includes: a case body; a case cover coupled to the case body; a control unit installed within the case body and having an electronic circuit board; and a plurality of setting knobs disposed to be spaced apart from one another on the electronic circuit board, having an indication unit exposed to the outside to indicate a current reference value and a trip operation time marked on the case cover, respectively, and configured to be rotatable, respectively.

Abstract: A circuit breaker trip unit includes an input section receiving a phase current level signal. A processor is in communication with the input section and generates a first trip signal based on the phase current level signal and user-adjustable trip settings. The trip settings include long time and short time pickup and delay settings. An analog instantaneous trip circuit is in communication with both of the input section and the processor. The analog instantaneous trip circuit includes a digital potentiometer having a non-volatile memory. The potentiometer provides a reference signal corresponding to a resistance setting stored in the memory. The analog instantaneous trip circuit compares the phase current level and reference signals, and generates a second trip signal based on a result of the comparing. The processor programs the resistance setting stored in the memory according to a user-adjustable instantaneous current pickup setting.

Abstract: In an example signal clustering apparatus, a feature of a signal is divided into segments. A first feature vector of each segment is calculated, the first feature vector having has a plurality of elements corresponding to each reference model. A value of an element attenuates when a feature of the segment shifts from a center of a distribution of the reference model corresponding to the element. A similarity between two reference models is calculated. A second feature vector of each segment is calculated, the second feature vector having a plurality of elements corresponding to each reference model. A value of an element is a weighted sum and segments of second feature vectors of which the plurality of elements are similar values are clustered to one class.

Abstract: A circuit protection system has a normal mode, and a maintenance mode with reduced potential arc flash energy. A downstream circuit breaker is mounted within a first enclosure comprising a first access panel. A locking mechanism locks the first access panel closed. An upstream breaker is mounted within a second enclosure comprising a second access panel. A current sensor senses current and is in communication with an electronic trip unit that controls current interruptions by the upstream breaker based on a trip setting. A user interface device is accessible when second enclosure is closed, and allows user selections of normal and maintenance modes. When maintenance mode is selected, the trip unit changes the trip setting such that potential arc flash energy is reduced. The system is configured to keep the first access panel locked closed based on normal mode being selected, and allow unlocking based on maintenance mode being selected.

Abstract: A compressor monitoring system includes current and voltage monitors, current and voltage averaging modules, a control module, and a switch. The current monitor measures a current drawn by a motor of a compressor. The current averaging module generates first and second average current values based on the current measured by the current monitor. The voltage monitor measures a utility power voltage. The voltage averaging module generates first and second average voltage values based on the voltage measured by the voltage monitor. The control module selectively generates a fault signal when a first ratio is greater than a first predetermined threshold and a second ratio is less than a second predetermined threshold. The first ratio is based on the first and second average current values. The second ratio is based on the first and second average voltage values. The switch deactivates the motor when the fault signal is generated.

Abstract: Methods and techniques to implement a digital signal processor for avoidance of audio feedback are disclosed, in particular, audio signal processing systems that reduce the requirement for physical segregation of sound acquisition and diffusion zones. In a more general aspect, the components and techniques described herein provide a for a sound space and sound processing equipment such that sound travelling electronically in a loop through the sound processing equipment that is output into a physical sound diffusion zone, received at the input to the sound processing equipment, and then re-amplified, etc. is attenuated over that loop by frequency modification. The frequency modification is such that, at least for some signals, on each pass through the loop, the sound processing equipment will attenuate or amplify individual sub-bands of the frequency spectrum of the audio signal that is received at the input of the sound processing equipment.

Abstract: An improved programmable logic control device for monitoring the current of a circuit and for signalling a circuit control device, the programmable logic control device including electrical power circuitry for activating the circuit control device and electrical circuitry for monitoring the current in the electrical circuit, the electrical circuitry including: adjustable electrical signal input circuitry to monitor the electrical current in the circuit; adjustable pick-up circuitry for adjusting the level of the current monitored in the electrical circuit, the pick-up circuitry having a thermister means for improved stabilization; adjustable time circuitry to command the electrical power circuitry to activate the circuit control device when the electrical current in the electrical circuit reaches the selected level and time duration, the time circuitry having an increased time duration to minimize nuisance tripping; and a zener diode in reverse mode for controlling the level of voltage applied to the adjustab

Abstract: A circuit breaker system and method having zone selective interlock features is provided. The system and method include the transmission of a selective interlock signal from a downstream circuit breaker to an upstream circuit breaker in the event a first or second fault condition is detected. The upstream circuit breaker upon receipt of this signal changes the response of the second circuit breaker depending on whether the first or second fault condition has been detected.

Abstract: The system of the invention includes a circuit breaker switching control section (100) and a setting control section (700) connected therewith through a communication network (500). The circuit breaker switching control section (100) transmits a circuit breaker state quantity acquired by a signal input section (120) through the communication network to a set value calculation section (740) of the setting control section (700). The set value calculation section (740) of the setting control section calculates a set value to be set in the switching control section (100) of the circuit breaker, using the state quantity of the circuit breaker that was transmitted thereto. The setting control section (700) transmits to the circuit breaker switching control section the set value calculated by the set value calculation section (730) through the communication network.

Abstract: A circuit breaker system and method having zone selective interlock features is provided. The system and method include the transmission of a selective interlock signal from a downstream circuit breaker to an upstream circuit breaker in the event a first or second fault condition is detected. The upstream circuit breaker upon receipt of this signal changes the response of the second circuit breaker depending on whether the first or second fault condition has been detected.

Abstract: A power supply (200) is provided having a plurality of independent current limiting circuits. A first current limiting circuit (6) provides protection against a short circuit or other extraneous load conditions, while a second current limiting circuit, using a trace on a PCB as a sensing element, is programmable on the basis of a time constant and a current level.

Abstract: A circuit breaker trip unit includes an input section receiving a phase current level signal. A processor is in communication with the input section and generates a first trip signal based on the phase current level signal and user-adjustable trip settings. The trip settings include long time and short time pickup and delay settings. An analog instantaneous trip circuit is in communication with both of the input section and the processor. The analog instantaneous trip circuit includes a digital potentiometer having a non-volatile memory. The potentiometer provides a reference signal corresponding to a resistance setting stored in the memory. The analog instantaneous trip circuit compares the phase current level and reference signals, and generates a second trip signal based on a result of the comparing. The processor programs the resistance setting stored in the memory according to a user-adjustable instantaneous current pickup setting.

Abstract: A gate driver 28 performs a normal charging operation for a power MOSFET 14 by driving a charge pump 90 solely, when a low-level control signal S1 (ON signal) is received during a normal state. On the other hand, if a low-level control signal S1 (ON signal) is received during a load anomaly state, an urgent charge FET 92, as well as the charge pump 90, is turned on when a load current IL exceeds a second anomaly threshold current ILfc, so that a rapid charging operation is performed.

Abstract: An auxiliary device for remote data transmission having processing means comprising a first input to receive a first data item of a state of the circuit breaker, and at least one command output to command transmission of data. The processing means comprise: a second input to receive at least one second data item representative of an electrical fault or of an auxiliary command, identification means to identify the type of electrical fault, and initialization means of the at least one command output. An auxiliary unit and a circuit breaker comprising the device. A method for implementing said device.

Abstract: A circuit breaker system and method having zone selective interlock features with separate restrained and unrestrained setting capability is provided. The system and method include the transmission of a selective interlock signal from a downstream circuit breaker to an upstream circuit breaker in the event of a fault condition. The upstream circuit breaker upon receipt of this signal changes the tripping response of the second circuit breaker to a restrained mode. The circuit breakers include features enabling the user to modify and adjust both the restrained and unrestrained trip curves associated with both the restrained and unrestrained modes of operation.

Abstract: A circuit protection system includes a normal mode and a maintenance mode. A current sensor senses current in the circuit. An enclosure includes an access panel that is movable between a closed position and open position. A circuit breaker is mounted within the enclosure. An electronic trip unit is in communication with the current sensor and controls interruptions of the current by the circuit breaker based on a trip setting. An interface device is accessible when said access panel is closed and allows selections of the normal and maintenance modes. A display, which is in communication with both of the user interface device and the electronic trip unit, monitors the interface device and transmits data to the trip unit that is based on the selected mode. The display receives data from the trip unit and displays information based on the received data. The display is viewable when the access panel is closed.

Abstract: A protection device for an oscillating power circuit, namely for a demining coil, such device incorporating circuit breaking means positioned between an alternating current supply network and the power circuit, such device wherein it comprises at least one means to measure and analyze the current supplying the power circuit, means able to detect the appearance of a direct current and connected to triggering means ensuring the opening of the circuit breaking means when the alternating current ceases.

Abstract: A circuit protection system includes a normal mode and a maintenance mode. A current sensor senses current in the circuit. An enclosure includes an access panel that is movable between a closed position and open position. A circuit breaker is mounted within the enclosure. An electronic trip unit is in communication with the current sensor and controls interruptions of the current by the circuit breaker based on a trip setting. An interface device is accessible when said access panel is closed and allows selections of the normal and maintenance modes. A display, which is in communication with both of the user interface device and the electronic trip unit, monitors the interface device and transmits data to the trip unit that is based on the selected mode. The display receives data from the trip unit and displays information based on the received data. The display is viewable when the access panel is closed.

Abstract: A circuit protection system includes a normal mode and a maintenance mode. A current sensor senses current in the circuit. An enclosure includes an access panel that is movable between a closed position and open position. A circuit breaker is mounted within the enclosure. An electronic trip unit is in communication with the current sensor and controls interruptions of the current by the circuit breaker based on a trip setting. An interface device is accessible when said access panel is closed and allows selections of the normal and maintenance modes. A display, which is in communication with both of the user interface device and the electronic trip unit, monitors the interface device and transmits data to the trip unit that is based on the selected mode. The display receives data from the trip unit and displays information based on the received data. The display is viewable when the access panel is closed.

Abstract: A circuit breaker system and method having zone selective interlock features with separate restrained and unrestrained setting capability is provided. The system and method include the transmission of a selective interlock signal from a downstream circuit breaker to an upstream circuit breaker in the event of a fault condition. The upstream circuit breaker upon receipt of this signal changes the tripping response of the second circuit breaker to a restrained mode. The circuit breakers include features enabling the user to modify and adjust both the restrained and unrestrained trip curves associated with both the restrained and unrestrained modes of operation.

Abstract: In a method and system for protecting a battery being charged by an electrical device, a current flowing through a cell stack of the battery is measured. If the measured current is greater than a predefined value the battery is isolated from the device. If subsequent current measurements made within a predefined time interval indicate that the measured current is less than or equal to the predefined value then the battery is recoupled to the device. If the measured current remains greater than the predefined value during the predefined time interval then a fuse is blown and the battery is disabled.

Abstract: An improved programmable logic control device for monitoring the current of a circuit and for signalling a circuit control device, the programmable logic control device including electrical power circuitry for activating the circuit control device and electrical circuitry for monitoring the current in the electrical circuit, the electrical circuitry including: adjustable electrical signal input circuitry to monitor the electrical current in the circuit; adjustable pick-up circuitry for adjusting the level of the current monitored in the electrical circuit, the pick-up circuitry having a thermister means for improved stabilization; adjustable time circuitry to command the electrical power circuitry to activate the circuit control device when the electrical current in the electrical circuit reaches the selected level and time duration, the time circuitry having an increased time duration to minimize nuisance tripping; and a zener diode in reverse mode for controlling the level of voltage applied to the adjustab

Abstract: The voltage generator circuit includes a regulator, a first sensor circuit, and a second sensor circuit. The first sensor circuit includes a first transistor, a first resistor, and an error amplifier. When V1>Vth, the error amplifier senses an overcurrent condition to provide feedback to the operational amplifier to limit an output current. The second sensor circuit includes a second transistor, a second resistor, and a sensing transistor. When the output current exceeds a sense threshold current, the sensing transistor is turned ON to provide feedback to the operational amplifier 12 to limit the output current. The second sensor circuit has a higher setting of sense threshold current than does the first sensor circuit, while having a higher setting of sensing speed than does the first sensor circuit.

Abstract: An electronic fuse comprising an integrated circuit having a control output terminal coupled to a control electrode of a power semiconductor switching device, the power semiconductor switching device being coupled in series with a load between first and second potentials, the integrated circuit further comprising a current sense input for sensing the current through the power semiconductor switching device, the integrated circuit further comprising a driver circuit for driving the power semi-conductor switching device, the driver circuit being coupled to a current limiting circuit responsive to the sensed current in the power semiconductor switching device, the current limiting circuit controlling the driver circuit whereby if the current through the power semiconductor switching device exceeds a predetermined threshold, the current limiting circuit generates a command to pulse the power semiconductor switching device on and off in a period of pulsed operation to maintain the current in the power semiconducto

Abstract: An electronic leakage current device a low-voltage power line, comprising: a moving contact and a fixed contact which can be mutually coupled/uncoupled; first sensor means for detecting a earth leakage current and for generating an electric signal which is indicative of the value of the earth leakage current; first electronic means which are electrically connected to the first sensor means in order to generate an electric tripping signal depending on the electric signal which is indicative of the value of the earth leakage current, said first electronic means generating the electric tripping signal after a preset minimum time interval; and actuation means, operatively connected to the moving contact, in order to perform, in response to the electric tripping signal: the separation of the moving contact from the fixed contact.

Abstract: The trip device comprises a system-powered power supply circuit comprising a capacitor for power supply of a trip coil. When the trip device is powered on, the capacitor charges and its voltage is regulated according to a first reference voltage sufficient to activate the trip coil if necessary. After a preset period, regulation of the voltage at the terminals of the capacitor is performed according to a second reference voltage, lower than the first voltage. The reference voltage reverts to the first value during the same preset period when the measured current reaches a preset threshold, which constitutes an indication of the presence of a fault that will lead to tripping being required. The capacitor is therefore generally charged at a lower voltage than that which is necessary for tripping, thus enabling its size to be reduced.

Abstract: A power supply feedthrough protection circuit which solves the problem of voltage feedthrough from a bus cable charging a chip power-supply beyond acceptable transistor limits. The circuit continuously senses the chip power-supply, compares the supply to an acceptable threshold, and provides a low-impedance current path as soon as the power-supply exceeds the threshold. The circuit allows a driver to draw current from the cable, in a controlled manner, and provides that the power supply is therefore never allowed to exceed the maximum allowable limit for transistors.