Abstract: A protection switching system in a power supply distribution system, comprises at least one protection switch (25) comprising a controllable semiconductor arranged to conduct current through the power supply line in a normal mode, a control unit (27) arranged to place the at least one protection switch in a test mode in which the current is reduced compared to the normal mode, registration means (28, 29) for registering a test mode value of at least one electrical characteristic in the power supply line that will be affected when the test mode is applied, a monitoring unit (30; 47) arranged to evaluate the at least one electrical characteristic and determine, based on the evaluation, whether or not an action should be taken. If a malfunction is detected an alarm is issued to indicate to service personnel that the protection switch should be replaced.

Abstract: A high sensitivity leakage current detection interrupter (LCDI) includes a shielded wire, a current leakage detection unit, and a tripping mechanism. A live core and a neutral core of the shielded wire are respectively wrapped in two conductive shell wires. The current leakage detection unit includes a pair of rectifying diodes reversely connected in series between a live line and a neutral line of a power supply, a voltage dropping resistor, thyristors, and resistor-capacitor (RC) voltage dropping filter circuits. The tripping mechanism includes control units with on/off respectively controlled by the thyristors. When either of the thyristors is turned on, the corresponding control unit is turned on, and the tripping mechanism is actuated to switch off the power supply.

Abstract: Fast turn on silicon controlled rectifiers for ESD protection. A semiconductor device includes a semiconductor substrate of a first conductivity type; a first well of a second conductivity type; a second well of the second conductivity type; a first diffused region of the first conductivity type and coupled to a first terminal; a first diffused region of the second conductivity type; a second diffused region of the first conductivity type; a second diffused region of the second conductivity type in the second well; wherein the first diffused region of the first conductivity type and the first diffused region of the second conductivity type form a first diode, and the second diffused region of the first conductivity type and the second diffused region of the second conductivity type form a second diode, and the first and second diodes are series coupled between the first terminal and the second terminal.

Abstract: A safety switching device, with which a safety-related device, can be set into a safe state. The safety switching device has a microprocessor or microcontroller, which can set an electric drive to be protected into a safe state both if an emergency circuit breaker, protective door switch, and/or two-hand switch is activated and also if there is faulty operation of the safety-related device or electric drive. For this purpose, the microprocessor is implemented such that it can determine from at least one analog signal to be measured whether a predetermined parameter lies outside a predetermined operating range. In addition, the microprocessor can be a component of a safety device which is constructed for multiple-channel control of a safety-related electric drive. In this way, the safety switching device can respond to several safety functions independent of each other in order to set an electric drive into a safe state.

Abstract: There is provided an electronic device that includes a heatsink and a set of IGBTs coupled to the heatsink and configured to deliver power to a field exciter and a battery. The electronic device also includes a temperature sensor disposed in the heatsink and a controller. The controller is configured to receive a temperature reading from the temperature sensor and, based on the temperature reading, determine a junction temperature for at least one of the IGBTs of the set of IGBTs. The controller is also configured to de-rate an output power provided by each of the IGBTs based, at least in part, on the junction temperature.

Abstract: An apparatus for short-circuit protection of a three-phase load in a three-phase system includes an input for connection of the apparatus to a three-phase network, an output for connection of the three-phase load to the apparatus, a means for producing an auxiliary short circuit in the three-phase network by ignition of the means, a means for identifying a short circuit at the three-phase load, and a means for generating an ignition pulse upon identification of the short circuit. The means for producing the auxiliary short circuit and the means for identifying the short circuit are provided in the current path between the input and the output. The means for producing the auxiliary short circuit is ignitable by the ignition pulse. The means for generating the ignition pulse is formed so that the ignition pulse can be generated by a short-circuit current established by the means for identifying the short circuit.

Abstract: A solid state switch module is provided for use in a power distribution network including an input differential protection connection for receiving a measured current value from an upstream module. The solid state switch module also includes an output differential protection connection for sending a measured current value. The solid state switch module includes a trip outlet for sending a trip signal to an upstream solid state switch, and a trip inlet for receiving a trip signal from a downstream solid state switch. The trip inlet is operably coupled to the switch. A current sensor measures the current value of a connected power transmission line across the solid state switch module. A summer adds a current input from a parallel module with the current measures by the current sensor. A comparator determines whether an amount of current lost between the solid state switch module and an upstream module is acceptable.

Abstract: A semiconductor device includes an output port that has a first lateral double diffused metal oxide semiconductor (LDMOS) device and an electrostatic discharge protection device that has a second LDMOS device and a bipolar transistor and that protects the output port from electrostatic discharge. A breakdown voltage of the second LDMOS device is equal to or lower than a breakdown voltage of the first LDMOS device.

Abstract: This is a solid state switch device, capable of receiving and differentiating electrical signatures by a number of electronic and optical elements, the arrangement of which makes it possible to recognize the type of fault condition (short circuit), to interrupt the current and to restore the latter automatically or manually with no electric arcs, no falls in the threshold, and no heat dissipation, thus increasing the service life, reducing the response time, and restoring the operation of the installation or electrical apparatus to be protected.

Abstract: An interface circuit configurable in input and output modes comprises a current source; an input/output node; a diode to prevent current from flowing from the input/output node to the current source; a first switch to short-circuit the diode when closed; and a second switch to form a ground path from the input/output node when closed. In input mode, the first switch is closed and the state of a connected sensor circuit may be measured. In the output mode, the first switch is open, and the second switch may be closed to activate an output circuit. In the output mode, power dissipation may be monitored, and the diode may protect the current source and measurement node from current flowing through the output circuit. In the input mode, closing the first switch may prevent the diode from introducing measurement errors due to non-linear attenuation of perturbative AC signals.

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 overcurrent protection circuit includes a universal serial bus (USB) controller having an overcurrent detection pin, and a plurality of USB connectors each electronically connected to a USB device and the overcurrent detection pin. The USB controller communicates with the USB devices respectively via the USB connectors. When the overcurrent detection pin detects an overcurrent occurrence in one of the USB devices, the USB controller stops communicating with all of the USB devices.

Abstract: A semiconductor device includes a sense resistor that converts a sense current flowing through a sense terminal of a switching element to a voltage (sense voltage), and an overcurrent protection circuit that performs a protection operation for the switching element when the sense voltage exceeds a threshold. The overcurrent protection circuit can switch the threshold to a first reference voltage, or to a second reference voltage which is lower than the first reference voltage. The overcurrent protection circuit sets the threshold to the second reference voltage at the time of the switching element being in a steady state, and sets the threshold to the first reference voltage during a mirror period immediately after turning-on of the switching element.

Abstract: When a short-circuit failure of any of switch portions (13) including switch elements (11) and parallel-connected feedback diodes (12) of an inverter circuit (7) is detected during the operation of a motor (1), a switch portion (13) where the short-circuit failure has occurred is checked for whether it is on the positive polarity side or the negative polarity side. The switch elements (11) are so controlled that all the switch portions (13) on the same polarity side as where the short-circuit has occurred are brought into a conducted state and all the others are disconnected. This prevents a large electric current from flowing into each switch portion of the inverter circuit without requiring any switch to block the power distribution between a motor and the inverter circuit when a short-circuit failure of the switch portion of the inverter circuit occurs.

Abstract: A system and method are provided for protecting a power grid against electric faults. A first circuit breaker is associated with a first electronic unit and positioned at a first hierarchy level. One or more additional circuit breakers, each including a corresponding second electronic unit, are positioned at one or more additional levels hierarchically lower than the first level and cascaded to each other. The first circuit breaker includes at least one semiconductor electronic breaking device. The first electronic unit is configured to, upon the appearance of an electric fault in a grid area, drive the breaking device to limit the current flowing through it for a predetermined period of time, and send to the circuit breakers on lower hierarchy levels an intervention command to allow intervention, among the circuit breakers that detected the fault, of the closest circuit breaker positioned immediately upstream from the area where the fault occurred.

Abstract: An ESD protection circuit including a first electrostatic discharge protection circuit provided between first power supply wiring and first ground wiring; a second ESD protection circuit provided between second power supply wiring and second ground wiring; a third ESD protection circuit provided between the first ground wiring and the second ground wiring; a PMOS transistor coupled to the first power supply wiring and provided between a first CMOS circuit coupled to the first ground wiring and the first power supply wiring, the first CMOS circuit receiving a signal from a first internal circuit and outputting a signal to a first node; an NMOS transistor provided between the first node and the first ground wiring; and an ESD detection circuit that renders the PMOS transistor conductive and the NMOS transistor non-conductive during normal operation, and renders the PMOS transistor non-conductive and the NMOS transistor conductive when an ESD is applied.

Abstract: A first overcurrent detecting circuit outputs a first time-up signal when a time period, in which an electric current flowing into the wire harness is greater than the first threshold, reaches a first duration time, which corresponds to a first threshold. A second overcurrent detecting circuit outputs a second time-up signal when a time period, in which an electric current flowing into the wire harness is greater than the second threshold, reaches a second duration time, which corresponds to a second threshold. The second threshold is less than the first threshold. The second duration time is longer than the first duration time. A determination circuit determines that an overcurrent flows into the wire harness and cause a control circuit to deactivate the switching element when inputting at least one of the first and second time-up signals.

Abstract: A self-adaptive surge-proof circuit is used in a switching power supply device. The switching power supply device includes an AC input, a filter-rectifier circuit connected to the AC input, and a power converter circuit connected to the filter-rectifier circuit. The self-adaptive surge-proof circuit includes a surge suppression unit connected between the filter-rectifier circuit and the power converter circuit, a switching unit connected in parallel with the surge suppression unit for adjusting an input impedance of the switching power supply device, a sampling unit connected to the filter-rectifier circuit for collecting a surge signal from the filter-rectifier circuit, and a drive-controlling circuit connected to the sampling unit for generating a driving signal for controlling on and off of the switching unit according to the surge signal.

Abstract: An interposer electrical interface for placing a DC-DC converter in close proximity with an IC powered by the converter, the DC-DC converter including at least one switching node power supply stage, the at least one switching node power supply stage providing regulated power to the IC, the close proximity of the DC-DC converter and IC allowing for high efficiency in provision of the regulated power from the DC-DC converter to the IC, the interposer electrical interface comprising at least one electrical energy storage element.

Abstract: A power transistor has a first current electrode coupled to a first power supply terminal and a second current electrode as an output of the circuit. A driver control circuit is coupled between a first and a second internal power supply node and is coupled to a control electrode of the power transistor. A first switch selectively couples the first power supply terminal to the first internal power supply node. A second power supply terminal is coupled to the second internal power supply node. A diode has an anode coupled to the second internal power supply node. A second switch is coupled between the diode and the output of the circuit such that, when the circuit is in active mode, it selectively couples the cathode of the diode to the output of the circuit based on whether or not the second power supply terminal is coupled to an external ground.

Abstract: An electronic circuit breaker of a power having dual output ports has an input port, two output ports, two field effect transistors, two current detection circuits and two control circuits. The control circuit has a silicon controlled rectifier (SCR) and an activation circuit detecting if a short circuit is present at one of the output ports through one of the current detection circuits, activating the SCR to turn off a corresponding FET after the occurrence of the short circuit, and disconnecting a corresponding output port from the input port. Due to the characteristics of the SCR, the SCR, once activated, stays in an on state between its anode and cathode. After the current of the output returns to its normal state, the FET is still turned off. Accordingly, high-frequency large current arising from alternately switching between the on and off states of the FET can be avoided.

Abstract: In a method for operating a power semiconductor circuit a power semiconductor chip is provided which includes a power semiconductor switch with a first load terminal and with a second load terminal. Further, a first temperature sensor which is thermally coupled to the power semiconductor switch and a second temperature sensor are provided. The power semiconductor switch is switched OFF or kept switched OFF if the temperature difference between a first temperature of the first temperature sensor and a second temperature of the second temperature sensor is greater than or equal to a switching-OFF threshold temperature difference which depends, following an inconstant first function, on the voltage drop across the power semiconductor switch between the first load terminal and the second load terminal.

Abstract: Solid state power controllers in various configurations are provided. One such solid state power controller includes a power connector, a load connector and at least one communication connector, a solid state switch electrically connectable between the power connector and the load connector, where the switch includes an input, a microcontroller coupled to the input of the solid state switch, and current sensing circuitry coupled to the microcontroller and configured to sense a current flowing through the solid state switch, the current sensing circuitry including an amplifier having an offset error, where the current sensing circuitry is configured to generate a signal indicative of the current flowing through the solid state switch, and bias the generated signal to a predetermined level to substantially eliminate the offset error in the amplifier.

Abstract: An object is to obtain a low-frequency circuit breaker which has a simple configuration and a small size as a whole and is advantageous in view of costs. There is provided a low-frequency circuit breaker, in which a semiconductor switch and a mechanical switch are connected in parallel with each other. The semiconductor switch is configured by connecting a thyristor and a thyristor in anti-parallel with each other. These members are controlled by the circuit breaker control circuit.

Abstract: A method of protecting against overcurrent conditions controls a solid state switch to turn OFF to prevent a flow of current along a first current path in response to an overcurrent condition exceeding a predefined current threshold, or a predefined current threshold and a predefined energy threshold. Current is selectively passed along a second current path that is parallel to the first current path in response to the solid state switch turning OFF. An overcurrent detection device that is upstream of the first current path and the second current path is used to detect at least partially via the second current path whether the overcurrent condition corresponds to a predefined fault condition downstream of the current paths.

Abstract: An electronic system can include a switch and a regulator coupled to the switch. The switch can be used to deliver electricity from a first terminal to a second terminal. The switch can also be used to prevent the second terminal from having a level that is higher than a predefined operation level limit by controlling the status of the switch according to a supply signal at the first terminal. The regulator can be used to adjust a regulated signal at the second terminal according to the supply signal.

Abstract: A solid state power controller (SSPC) for a direct current (DC) electrical system includes a high bandwidth fault detector, the high bandwidth fault detector configured to detect a possible fault and place a power switch of the SSPC in saturation at a predetermined current limit; and a low bandwidth fault detector, the low bandwidth fault detector configured to determine whether the possible fault is a confirmed fault, and in the event the possible fault is determined to be the confirmed fault, turning off the power switch, or in the event the possible fault is determined not to be the confirmed fault, turning on the power switch at a minimum on-resistance.

Abstract: A controller 43 turns on a semiconductor switch 41 in a normal mode, and turns off the semiconductor switch 41 in a sleep mode. A bypass resistor 5 is connected in parallel to the semiconductor switch 41. A resistance value of the bypass resister 5 is so large as that in the sleep mode, a dark current is supplied to an electronic device 3 via the bypass resistor 5, and if an electric wire downstream of the bypass resistor is short-circuited, an electric current more than a permissive current is prevented from flowing to the electric wire.

Abstract: High-power power distribution in an aircraft may use solid state power controller (SSPC) technology. A conventional electromechanical contactor may be used, in series, with a solid state switching device (SSSD) to achieve high-power power distribution. Since the electromechanical contactor does not need to be rated for arc handlings during normal SSPC operation, the electromechanical contactor may be simplified, resulting in cost, weight, volume, and failure rate reductions. The power distribution apparatus and methods of the present invention may be applicable for both alternating current (AC) and direct current (DC) applications and can be modified to form a three phase SSPC.

Abstract: An electronic monitor for monitoring characteristics of an AC power line for swells, sags, RMS voltage, impulses, total harmonic distortion (THD) and frequency. The waveform is received at the monitor, scaled to a lower magnitude, rectified by an op amp with zero offset voltage, converted a digital form which is representative of the waveform and processed to determine the occurrence of any irregularity in the AC power waveform. Two DMA channels are used to store each cycle, or groups of cycles, of the waveform into two buffers for further processing. An input surge protective circuit limits impulse voltage to the power supply. Related methods are also disclosed.

Abstract: In order to form an overcurrent switching apparatus for medium-voltage or high-voltage applications with a current detection device for changing over a contact system associated with them from a first state to a second state in the event of a threshold current being exceeded, the switching properties of which overcurrent switching apparatus are precise, an actuating device is disposed downstream of the current detection device, which is in a first current branch, via a coupling device. The actuating device is configured to change over the contact system, which is in a second current branch, from the first to the second state.

Abstract: A protection circuit includes a switch and a transistor. A first end of the switch is connected to a power source. A second end of the switch is connected to an electronic device via a first resistor. A third end of the switch is connected to the power source via a second resistor. A base of the transistor is connected to the second of the transistor via a third resistor, and grounded via a fourth resistor. A collector of the transistor is connected to the power source. An emitter of the transistor is connected to the electronic device.

Abstract: An induction motor drive includes a plurality of inverters, a changeover switch which changes over outputs of the plurality of inverters to be supplied to one induction motor and a changeover controller which controls the changeover switch on the basis of a failure detection signal of one inverter to change over from the one inverter to another inverter to start the other inverter so that the induction motor is driven. The changeover controller includes a frequency/phase detector which always detects a frequency and a phase of a terminal voltage of the induction motor and a starting frequency/phase setting device which controls a frequency and a phase at starting of the other inverter in accordance with detected values of the frequency/phase detector when the failure signal is inputted.

Abstract: The present invention relates to a battery protection circuit for protecting a plurality of batteries connected in series. The battery protection circuit includes: a controller for monitoring the batteries and outputting control signals based on predetermined conditions associated with the batteries; a first N-channel MOSFET and a second N-channel MOSFET coupled in a common-drain configuration in a low-side path, wherein at least one of the first and second N-channel MOSFETs turns off in response to the control signal received from the controller when at least one of the predetermined conditions is detected; and a gate protection circuit for preventing gate-to-source voltages of the first and second N-channel MOSFETs from exceeding a predetermined gate-to-source voltage level.

Abstract: In a charging circuit charging a battery based on a power supply voltage from an external power supply, a charging transistor is provided on a path from the external power supply to the battery. A charging control circuit is integrated on a semiconductor substrate, and adjusts an ON state of the charging transistor to control a charging current supplied to the battery. The voltage adjusting circuit provided on an electric power supply path from the external power supply to a power supply terminal of the charging control circuit generates a necessary voltage drop. The current adjusting circuit adjusts the ON state of the charging transistor such that a voltage of the battery is brought close to a predetermined voltage value. The clamp circuit clamps a voltage at the power supply terminal of the charging control circuit below a predetermined clamp voltage.

Abstract: An over-current protection device for use in a switched mode power supply prevents over-current conditions caused by short-circuits faults. The over-current protection device monitors a current in the switched mode power supply, and in particular, determines a peak current value associated with the monitored current. The monitored current is compared to a reference value to determine whether an over-current condition exists. If an over-current condition is detected, then the over-current protection device modifies the ‘off’ time of the switched mode power supply based on the determined peak current value.

Abstract: Methods and apparatus to provide leakage power estimation are described. In one embodiment, one or more sensed temperature values (108) and one or more voltage values (110) are utilized to determine the leakage power of an integrated circuit (IC) component. Other embodiments are also described.

Abstract: An over-current electronic protection system includes a first solid state reversibly interruptible electronic switch including first output control logic and first controlled output channels controlled by the first control logic. The first output control logic reversibly interrupts power at any output channel when their current exceed limits. The system includes a second solid state reversibly interruptible electronic switch including second control logic and second controlled outputs. A power supply input of the second switch is coupled to one of the first controlled output channels to receive the power. The second controlled outputs provide power to loads under normal operating conditions and reversibly interrupt the power for second output channels when their current exceeds limits. A CPU having is coupled to the second output channels and external inputs of the second switches via an isolation device to provide a supervisory and monitoring function.

Abstract: A driver circuit comprising an insulated gate bipolar transistor having a collector coupled to a voltage supply, an emitter coupled to a source of reference potential, and a gate configured to receive a control signal from a driver circuit, and a desaturation circuit conductively coupled between an insulated gate and a collector of the insulated gate bipolar transistor to desaturate the insulated gate. The desaturation circuit includes a series coupled bias voltage source, uni-directionally conducting element and switch.

Abstract: A selectively protected electrical system includes or operates with a power source, a load, a power driver circuit for controllably transferring power from the power source to the load, the power driver circuit being encapsulated in a potting material, and a controller for enabling and disabling the power driver circuit, the controller being un-encapsulated by the potting material. If a contaminant induced electrical fault occurs in the selectively protected electrical system, the electrical fault is more likely to occur in the un-encapsulated controller, such that the selectively protected electrical system is disabled. The contaminant is inhibited from contacting and inducing an electrical fault in the power driver circuit, thus providing for a controlled failure of the selectively protected electrical system.

Abstract: An electronic assembly for switching electric power, comprising two power supply buses spaced from each other between which semiconductor switches to be driven by means of a control input are arranged at a power output for providing electric power, a capacitor arrangement bridging the two power supply buses, which extends at least partially over the length of the power supply buses, two contact layers originating from one each of the power supply buses and covering the capacitor arrangement at least partially, with the contact layers comprising free end portions which mutually project one another towards the respective other one of the power supply buses, and with the two contact layers having a freely accessible contact area each which is adapted for contact making with correspondingly configured power terminals.

Abstract: A subject of the present invention is to reduce noise caused by ringing or the like while reducing turn-on power loss of the element and reverse recovery loss of the diode in a switching circuit of a power semiconductor element to which a SiC diode having small recovery current is connected in parallel. A means for solving the problem is to detect gate voltage and/or collector voltage of the power semiconductor switching element and change gate drive voltage in several stages based on the detected value.

Abstract: An overcurrent detection circuit in accordance with an exemplary aspect of the present invention includes a detection transistor, a potential difference setting unit, and a first transistor whose current value is controlled by the potential difference setting unit. Further, the potential difference setting unit includes a first depletion type transistor, a power-supply voltage being supplied to the drain of the first depletion type transistor, and the gate and source of the first depletion type transistor being connected to the gate of the first transistor, a second transistor, the drain and gate of the second transistor being connected to the gate of the first transistor, and a second depletion type transistor provided on the current path between the sources of the first transistor and the second transistor, the gate and drain of the second depletion type transistor being connected to the source of the detection transistor.

Abstract: A cable fault detection component (168) receives input data indicative of a fault in an electrical power system. The component (168) analyzes the input data to determine if the fault is indicative of a self-clearing cable fault and generates corresponding output data (276). In one implementation, the cable fault detection component (168) is implemented as a software module which operates on a computer (105) of a substation intelligence system (104).

Abstract: An electromechanical/solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.

Abstract: In order to compensate fluctuation of the characteristics of a field effect transistor and detect capacitive change of a capacitive element for measurement with high precision, the electronic circuit of the present invention includes; a transistor outputting current in response to voltage change, which is supplied from a variable voltage source to a current control terminal by capacitive coupling via the capacitive element for measurement; and the constant current source to output reference current; and the current detection circuit to detect output current outputted from the transistor. After making the reference current pass through the transistor and compensating fluctuation of threshold voltage, a switching element is turned “OFF” so as to make the current path between the gate and the drain of the transistor to be non conductive.

Abstract: In order to form an overcurrent switching apparatus for medium-voltage or high-voltage applications with a current detection device for changing over a contact system associated with them from a first state to a second state in the event of a threshold current being exceeded, the switching properties of which overcurrent switching apparatus are precise, an actuating device is disposed downstream of the current detection device, which is in a first current branch, via a coupling device. The actuating device is configured to change over the contact system, which is in a second current branch, from the first to the second state.

Abstract: A safety device for a semiconductor switch controlling a secondary line provided with a fuse on the input side of the switch device that includes component to create a short circuit in the secondary line, so as to cut off the fuse, and means of activating this component following detection of an overcurrent in the secondary line.

Abstract: A semiconductor device includes an anode electrode in Schottky contact with an n-type drift layer formed in an SiC substrate and a JTE region formed outside the anode electrode. The JTE region is made up of a first p-type zone formed in an upper portion of the drift layer under an edge of the anode electrode and a second p-type zone formed outside the first p-type zone having a lower surface impurity concentration than the first p-type zone. The second p-type zone is provided 15 ?m or more outwardly away from the edge of the anode electrode. The surface impurity concentration of the first p-type zone ranges from 1.8×1013 to 4×1013 cm?2, and that of the second p-type zone ranges from 1×1013 to 2.5×1013 cm?2.

Abstract: A current limiter includes a circuit device including a power supply transformation circuit to transform a power supply, a detection circuit to detect and transform a load current of a load into an output voltage, a control circuit to interrupt a connection between the power supply and the load according to the output voltage, a reset switch circuit to connect the power supply with the load, and a protection circuit including a warning element. Thus, when the power of the load exceeds a predetermined value, the current limiter will shut the power supply automatically to turn off the load to prevent the load from being worn out due to an excessive load current and to turn on the warning element to inform a user of the overload of the load.