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: An overcurrent protection circuit connected between a voltage input and a voltage output of an electronic device to protect against excessive current is disclosed. The overcurrent protection circuit includes first to fifth resistors, a relay comprising a coil and a normally closed switch, a pnp transistor, and a break-over element. When a current between the voltage input and the voltage output is greater or equal to a rated current of the electronic device, the npn transistor is turned on, while the coil is powered on to control the switch to be opened, therefore the voltage output cannot output voltage, which can protect against excessive current damaging the electronic device.

Abstract: A comparator receives, on its second input terminal, a third anomaly threshold voltage from a threshold voltage generator, and outputs a low-level breaking indication signal to a control logic portion when a terminal voltage falls below the third anomaly threshold voltage. Three threshold setting resistors are serially connected between the source of a power MOSFET and a ground terminal. A divided voltage at the connecting point between the threshold setting resistors and is outputted as the third anomaly threshold voltage.

Abstract: A programmable fuse and fuse panel are described. Unlike conventional fuses and fuse panels, the trip values of the fuses of the panel—i.e., the current values at which the fuse trips—are field programmable. One of many advantages includes the ability to adaptively set the trip value of a fuse—depending on the operating needs of a load device—without having to physically exchange the fuse. In an embodiment, electronic fuses are used.

Abstract: A protection circuit apparatus comprises a retriggerable fuse having an awakened state and a sleep state. The retriggerable fuse has an input and an output and is arranged, when in the awakened state, to selectively prevent a load current from flowing from the input to the output in response to the load current exceeding a first current threshold. An activation circuit is also provided and is arranged to sense the load current being drawn. The activation circuit causes the retriggerable fuse to enter the awakened state from the sleep state when the sensed load current exceeds a second current threshold.

Abstract: A remote power controller (RPC) includes a line connection; a load connection; a first field effect transistor (FET) and a second FET arranged in parallel between the line connection and the load connection, wherein the first FET has a lower safe operating area (SOA) than a SOA of the second FET, and wherein the first FET has a lower resistance at saturation (RDS(on)) than the second FET; and a voltage offset element connected between the first FET and the second FET, such that in the event that a current in the RPC is above a current limiting setpoint, the voltage offset element is configured to cause the first FET to turn off.

Abstract: In one embodiment, a method for sensing an output fault condition is disclosed. The method includes monitoring an error signal that indicates an output fault condition, and monitoring an input signal having a duration. An error flag is set if a fast switching mode is detected and if the error signal is asserted within a specified time interval during the input signal duration.

Abstract: A semiconductor device includes an ESD device region disposed within a semiconductor body of a first semiconductor type, an isolation region surrounding the ESD device region, a first doped region of a second conductivity type disposed at a surface of the semiconductor body within the ESD region, and a second doped region of the first conductivity type disposed between the semiconductor body within the ESD region and at least a portion of the first doped region, where the doping concentration of the second doped region is higher than the semiconductor body. A third doped region of the second semiconductor type is disposed on the semiconductor body and a fourth region of the first conductivity type is disposed over the third doped region. A fifth doped region of the second conductivity type is disposed on the semiconductor body. A trigger device and an SCR is formed therefrom.

Abstract: An embodiment of the invention relates to a switch-mode power converter including an inductor and an external rectifying diode. A series arrangement of a resistor and a switch are coupled in parallel with the external rectifying diode. The resistor and the switch enable continuous conduction mode, even at substantially no output current. A comparator senses a current level in the resistor. When the current level crosses a threshold level, the power converter is shut down. The current level is sensed with a second resistor coupled to a current source to produce a current sensing arrangement dependent on a ratio of resistances. Advantageously, the current level is sensed with clamp circuits coupled to the comparator, each clamp circuit including a series circuit arrangement of a field-effect transistor with a gate coupled to a voltage source.

Abstract: An overstress protection apparatus includes a switch detector. The switch is arranged in a grounding path of a load system. The detector detects the current, voltage or temperature of the load system to determine a signal for controlling the switch, to thereby protect the load system working in normal conditions.

Abstract: A motor drive device includes: chopping signal generation means for generating a chopping signal Sa when drive current of a driver has reached a first threshold value; chopping signal cut-off means for cutting off the chopping signal Sa when the drive current has reached a second threshold value which is greater than the first threshold value; and overcurrent protection means for generating an overcurrent protection signal Se when the drive current has reached a third threshold value which is greater than the first threshold value and its continuation time has reached a predetermined threshold value time. Thus it is possible to simultaneously obtain the constant current chopping function and the overcurrent protection function and to improve its reliability and safety.

Abstract: A power distribution system and method has a controller and at least one semiconductor switch. The power distribution system additionally has an on status detector which detects the status of the semiconductor switches, and an overcurrent status circuit which checks for overcurrent conditions.

Abstract: The DC switch includes a housing (2) provided with a power connection terminal (2a) adapted in use to be connected to a power source, and a load connection terminal (2b) adapted in use to be connected to a load. A contact unit (1) is interposed between the power connection terminal (2a) and the load connection terminal (2b). The contact unit (1) has mechanical contacts (10), and a semiconductor switch (11) serially connected to the mechanical contacts (10). The DC switch further includes a switching mechanism unit (3) having an operating handle (30) used for manual operation and movably attached to the housing (2), a position detection unit (4) configured to detect an operating position of the operating handle (30), and a control unit (7). The switching mechanism unit (3) is configured to open and close the mechanical contacts (10) in response to the manual operation of the operating handle (30).

Abstract: A semiconductor device includes a semiconductor switch element having a first conductive electrode and a second conductive electrode, and a voltage measurement circuit for measuring voltage between the first conductive electrode and the second conductive electrode of the semiconductor switch element. The voltage measurement circuit includes a constant voltage element connected in parallel with the semiconductor switch element for limiting voltage applied in a conducting direction of the semiconductor switch element to a prescribed value, a control switch connected in parallel with the constant voltage element, and a switch control unit turning on the control switch when the semiconductor switch element is off, and turning off the control switch when the semiconductor switch element is on.

Abstract: A semiconductor device includes an ESD device region disposed within a semiconductor body of a first semiconductor type, an isolation region surrounding the ESD device region, a first doped region of a second conductivity type disposed at a surface of the semiconductor body within the ESD region, and a second doped region of the first conductivity type disposed between the semiconductor body within the ESD region and at least a portion of the first doped region, where the doping concentration of the second doped region is higher than the semiconductor body. A third doped region of the second semiconductor type is disposed on the semiconductor body and a fourth region of the first conductivity type is disposed over the third doped region. A fifth doped region of the second conductivity type is disposed on the semiconductor body. A trigger device and an SCR is formed therefrom.

Abstract: Provided is a power supply control apparatus including an overcurrent detection circuit having an overcurrent detection accuracy improved. The power supply control apparatus according to the present invention includes: a transistor Q2 which produces a detection current dependent on a current flowing through an output transistor; a transistor 9 which produces the current Iref1 based on a bias signal BS1; a transistor 10 which produces the current Iref2 based on a bias signal BS2 different from the bias signal BS1; a current mirror circuit which outputs an overcurrent detection signal based on the current Iref1, the current Iref2 and the detection current; and a reference voltage production circuit 18 which produces the bias signal BS1 and the bias signal BS2. The reference voltage production circuit 18 includes: a resistor 21 arranged between a terminal for outputting the bias signal BS1 and a terminal for outputting the bias signal BS2; and a zener diode 37 connected in parallel with the resistor 21.

Abstract: A safety circuit for use in low-voltage systems improves safety of and additional features to low-voltage connections. When incorporated into a battery, the circuit leaves the battery disconnected from the low-voltage system until it determines that it is safe to make a connection. When the safety circuit determines that no unsafe conditions exist and that it is safe to connect the battery, the safety circuit may connect the battery by way of a “soft start” that provides a connection over a period of time that reduces or prevents inductive voltage spikes on the low-voltage system. A method is used for detection of proper polarity of the connections between the battery and the low-voltage system. When incorporated into a jumper cable, the safety circuit provides communication abilities, can provide test abilities, and improves connection safety and functionality, such as allowing transfer of power between low-voltage systems having different voltages.

Abstract: A drive circuit that controls a switching device ON/OFF and a soft cutoff command circuit that gradually decreases the gate terminal voltage of the switching device when short circuit of the switching device is detected. Additionally, an ON-pulse retention command circuit retains the output of the drive circuit ON when the gate terminal voltage is judged to have exceeded a specified value by a gate voltage judgment comparator that detects the gate terminal voltage of the switching device.

Abstract: A battery protection and monitoring system includes a plurality of MAFET (Mechanically Actuated Field Effect Transistor) switches, wherein each MAFET switch among the MAFET switches is capable of switching from an open switch condition to a closed switch condition or vice versa, such that the plurality of MAFET switches are connectable to a battery. Such a system further includes one or more transistors associated with and which communicate electrically with at least one MAFET switch among the MAFET switches. A PPTC (Polymeric Positive Temperature Coefficient) device is also associated with the transistors and the MAFET switches, such that the PPTC device, the MAFET switches and the transistors operate in association with one another and the open switch condition or the closed switch condition of the plurality of MAFET switches to identify, monitor and thus prevent at least one dangerous condition associated with the battery.

Abstract: A load driving device including a semiconductor switch arranged in a current path extending from a power supply to a load. A control circuit controls activation and deactivation of the semiconductor switch. The control circuit deactivates the semiconductor switch when it is determined that overcurrent is flowing through the current path. A current detector detects current that is flowing through the current path. The control circuit determines that overcurrent is flowing when the current detector continuously detects current that is greater than a threshold value over a predetermined detection time. The detection time is set to be shorter than the time from when the current in the current path exceeds the threshold value to when an increase in resistance value of the semiconductor switch resulting from heat generated by the current lowers the current to the threshold value.

Abstract: Provided is an electronic circuit including an upper control unit and a lower control unit. The upper control unit performs a logic transition of a gate signal so as to off-latch an upper switch by using the fall edge of a drive signal as a trigger and release the off-latch of the upper switch by using the rise edge of a monitor signal as a trigger. The lower control unit performs a logic transition of the gate signal so as to off-latch a lower switch by using the rise edge of the drive signal as a trigger and release the off-latch of the lower switch by using the rise edge of a monitor signal as a trigger.

Abstract: A transient blocking unit (TBU) is an arrangement of two or more transistors connected to each other in series such that they automatically switch off when a TBU current passing through these transistors exceeds a predetermined threshold. Voltage turnoff capability is provided for a TBU by adding a voltage comparison circuit to the TBU. The voltage comparison circuit provides gate voltages to one or more of the TBU transistors that tend to turn off the TBU transistors, if the voltage at the TBU output (i.e., the protected device output voltage) falls outside a predetermined range. The voltage provided by the voltage comparison circuit adds constructively to the gate voltages provided by normal TBU operation. Accordingly, TBU switch off can be driven by an over-current condition (TBU current out of range) and/or by an over-voltage condition (TBU output voltage out of range).

Abstract: A protection device detects a temperature in a predetermined monitoring place in an electronic apparatus 3 to protect the electronic apparatus 3, and includes an oscillating circuit 20 for generating a clock signal Vck having a predetermined cycle and a predetermined ON time, and a temperature detection circuit 16 for detecting the temperature in the monitoring place during the ON time of the clock signal Vck. The protection device shuts off supply of electric power to the electronic apparatus 3, when the temperature in the monitoring place exceeds a predetermined temperature.

Abstract: An isolation device having normally off detection is provided. The isolation device having normally off detection includes a transient blocking unit (TBU) having at least one depletion mode device disposed between a pair of sense terminals, and at least one normally off transition element disposed to drive a gate of the depletion mode device in the TBU, where the normally off transition element transitions from a first resistive state to a second resistive state and one depletion mode device is connected to one sense terminal, and the normally off transition element transitions by detection of a current through the TBU. The TBU can be unidirectional or bidirectional.

Abstract: A gate driver circuit of a voltage drive type power semiconductor switching device capable of speeding up di/dt and dv/dt even during large-current driving to thereby reduce the switching loss is disclosed. This power semiconductor switching device gate driving circuit includes a drive circuit which applies a drive signal to the gate electrode of the power semiconductor switching device and a measurement unit for measuring a flow current of the power semiconductor switching device. Based on a detected value of the flow current of the power semiconductor switching device, the gate is made variable in mirror voltage thereof.

Abstract: A system for regulating high speed voltage surges, particularly as a result of lightning strikes, which includes a transistor, an isolated voltage provider, and an array of voltage regulating electrical components, where the isolated voltage provider maintains the transistor in a fully on mode unless a voltage surge occurs. In the case of a voltage surge the array of voltage regulating electrical components switches the transistor to linear mode thus providing protection equal to its rating. A method of determining the voltage rating of individual Zener diodes contained within a Zener diode array consisting of shorting out individual diodes from the array and measuring the total voltage rating, then comparing the total voltage rating of the array with no diodes shorted out to the voltage rating of the array with the one diode shorted out.

Abstract: A short-circuit protection circuit includes a power supply, a first resistor, and an optocoupler. The optocoupler includes a light-emitting diode and a phototransistor, one end of the first resistor is connected to the anode of the power supply and the other end of the first resistor is connected to the anode of the light-emitting diode, the cathode of the light-emitting diode is grounded, the collector of the phototransistor is connected to the anode of the power supply, and the emitter of the phototransistor is grounded via a load circuit, the cathode of the power supply is grounded, when a short circuit occurs in the load circuit, the light-emitting diode turns off, the phototransistor turns off accordingly, and the voltage of the power supply does not provide voltage to the load circuit.

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: A method and associated system are disclosed for verifying charging failures for smart batteries by measuring input charging voltage and associated systems. In one embodiment, a determination is made whether or not a charging current is indicative of a battery failure by utilizing an analog-to-digital (A/D) port to measure the input charging voltage. As long as the measured input charging voltage is below the cell pack voltage or some set voltage value, whichever is higher, the BMU considers a charging current detection to be a false failure indication. If the measured charging voltage is above the cell pack voltage and the set voltage value, the BMU considers the charging current detection to be a positive failure indication. The BMU can then disable the battery or implement other verification steps before disabling the battery, as desired.

Abstract: A safety circuit includes a thermal fuse electrically connected in a main current path so that an electric current flowing in the main current path flows through the thermal fuse; a switching element electrically connected to the thermal fuse to cause the thermal fuse to open and interrupt the electric current flowing in the main current path when the switching element is turned on; a microcontroller electrically connected to the switching element and the main current path to turn on the switching element when an overcurrent flows in the main current path; and a noise removing unit electrically connecting the microcontroller to the switching element.

Abstract: A drive circuit that controls a switching device ON/OFF and a soft cutoff command circuit that gradually decreases the gate terminal voltage of the switching device when short circuit of the switching device is detected. Additionally, an ON-pulse retention command circuit retains the output of the drive circuit ON when the gate terminal voltage is judged to have exceeded a specified value by a gate voltage judgment comparator that detects the gate terminal voltage of the switching device.

Abstract: A multi-level over-current electronic protection system for protecting a plurality of outputs includes a first solid state reversibly interruptible electronic switch including first output control logic and a plurality of first controlled output channels controlled by the first control logic. The first switching device is coupled to receive power from at least one power supply selected to power a plurality of loads. The first switching device provides power at its plurality of first output channels under normal operating conditions, wherein the first output control logic is operable for reversibly interrupting power at any of the first output channels when current in any of the first output channels exceed limits for the first output channels. At least one second solid state reversibly interruptible electronic switch including second control logic and a plurality of second controlled outputs control by the second control logic is also provided.

Abstract: An overcurrent protection mechanism is provided for a battery pack that removably attaches to a power tool. The mechanism includes: one or more battery cells disposed in a battery pack; a current sensor configured to sense current supplied by the battery; a switch in a circuit path with the battery cells; and a battery control unit implemented as software instructions in a controller embedded in a battery pack. The battery control unit is configured to receive a signal indicative of current from the current sensor and control the switch to interrupt current flow from the battery cells as a function of current and time.

Abstract: In a load-driving apparatus with a FET between a battery and a load, an overcurrent detection circuit has a function generation circuit with a voltage divider circuit and a comparator. The voltage divider circuit has a pair of resistors connected to a drain of the FET, and a Zener diode connected to a connection point in parallel to the second resistor. The comparator compares a reference voltage at the connection point with a variable voltage of the FET, and outputs an overcurrent detection signal when the variable voltage becomes lower than the reference voltage. When no overcurrent exists and the battery voltage is not decreasing, the connection point is kept at a breakdown voltage of the Zener diode, and the difference with respect to the source voltage of the FET becomes particularly large. The comparator therefore does not erroneously output an overcurrent detection signal even when noise enters the system.

Abstract: An insulated gate bipolar transistor and a protective circuit are incorporated. The protective circuit has first and second Zener diodes connected in series in directions opposite to each other between the gate and the current sense terminal of the insulated gate bipolar transistor, and third and fourth Zener diodes connected in series in directions opposite to each other between the gate and the emitter of the insulated gate bipolar transistor.

Abstract: A power semiconductor device is provided with an output transistor, a load control circuit, and a pull-up circuit. The output transistor is connected between a power supply terminal provided to receive a power supply voltage and an output terminal to be connected with a load. The load control circuit is adapted to feed the gate voltage to the gate of the output transistor. When short-circuiting of the load occurs, the load control circuit stops feeding the gate voltage to the output transistor. The pull-up circuit is connected between the power supply terminal and the gate of the output transistor. The pull-up circuit is adapted to discharge electric charges on said gate of said output transistor, when short-circuiting of the load occurs with the voltage level on the power supply terminal lowered than the power supply voltage.

Abstract: An integrated circuit is disclosed including a primary input for receiving an input voltage, a battery voltage input for receiving a battery voltage signal and an output for providing an output voltage higher than the battery voltage. First circuitry responsive to the input voltage is provided for turning off the output voltage responsive to an input over voltage condition. Second circuitry responsive to the battery voltage signal is provided for turning off the output voltage responsive to a battery over voltage condition. Third circuitry provides for over current protection.

Abstract: The invention relates to a device for measuring current in an inductor and being connected in parallel with said inductor. The device includes a network in parallel with the inductor and connected to the terminals A and B comprising a resistor R2 in series with a resistor R1 in parallel with a capacitor C1; a voltage offset circuit having a DC voltage generator E connected in parallel with an offset resistor (Roffset) in series with two parallel resistors R3 and R4, the positive pole of the voltage source being connected to terminal B of the inductor; a temperature compensation circuit comprising a current source controlled as a function of the temperature, one of the two terminals of the current source being connected to the negative pole of the generator E, the other terminal of the current source being connected to different points of the measurement device.

Abstract: An apparatus and method for protecting an AC load from half-wave rectified power detects a half-wave rectified voltage or current, sets a status indication indicating the type of asymmetric fault causing the half-wave rectified power, and selectively turns the SSPC ON or OFF depending on the type of fault. There are two example circumstances that can cause an asymmetric fault: when the SSPC is OFF and a switch is shorted (“SSPC Failed Shorted”), or when the SSPC is commanded ON and a switch remains open (“SSPC Failed Open”). If the SSPC is OFF when the half-wave rectified AC voltage or current is detected, an “SSPC Failed Shorted” status indication is set, and the SSPC is turned ON to clear the fault. If the SSPC is commanded ON when the half-wave rectified AC voltage or current is detected, an “SSPC Failed Open” status indication is set, and the SSPC is turned OFF to clear the fault.

Abstract: A method consistent with an embodiment may include selecting one of a plurality of components of a power supply system of a cordless power tool to be a protected weak link element. The method may also include configuring the protected weak link element to fail from an overload condition before failure of a remainder of the plurality of components from the overload condition, monitoring a power condition of the protected weak link element, and protecting the protected weak link element from the overload condition to thereby also protect the remainder of the components from the overload condition. A battery pack and a cordless power tool are also provided.

Abstract: A circuit arrangement is disclosed herein having an input terminal configured to receive an input voltage, and an output terminal to provide an output voltage for a load. A first transistor with a load path and a control terminal is connected between the input terminal and output terminal. A first resistance element is connected between the control terminal of the first transistor and the input terminal. A first driver circuit is connected to the control terminal of the first transistor and is configured to control a current flow through the first transistor in a forward direction. A second driver circuit is provided which is designed to detect a voltage difference between the input terminal and output terminal, and then to drive this first transistor as a function of the voltage difference in a blocking action.

Abstract: A semiconductor device comprises an output transistor for controlling current that flows between a first terminal and a second terminal, a detection transistor connected in parallel with the output transistor, a detection resistor connected in series with the detection transistor, for detecting current that flows through the detection transistor as detection voltage and of which the resistance value is set in proportion to the potential difference between the first terminal and the second terminal and an over-current protection transistor for decreasing the ON current of the output transistor and the detection transistor according to the increase of the detection voltage.

Abstract: Short circuit protection is provided for an isolation component that has a parasitic diode as an inherent part of its construction. The isolation component may or may not be contained in an integrated circuit. In response to detecting a short circuit condition based on voltages at one or more input terminals of the integrated circuit, or based on current between the terminals, the isolation component is activated to facilitate current flow through the isolation component, such as to reduce total power dissipation in the isolation component during at least part of the short circuit condition.

Abstract: A circuit of interface between a logic sensor and a logic input isolation barrier of a processing circuit, including an element of protection against input overvoltages, a current-limiting circuit connected in series between an input terminal and an output terminal of the interface circuit, and a control stage connected in parallel with the galvanic isolation element to be controlled to control the logic states thereof, the control stage inhibiting the operation of the galvanic isolation element if the input current is smaller than a predetermined threshold.

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: A system and method for protecting an output transistor in an audio amplifier output stage includes a protection circuit that protects the output transistor from excessive currents and voltages, and does not interfere with the normal operation of the output transistor. The protection circuit generates an estimate of the power dissipated by the output transistor, applies this estimate to an electrical analog of the thermal time constants of the transistor to obtain an estimate of the temperature differential between junction and case, compares this differential to a limit, which is a function of transistor case temperature.

Abstract: A method for detecting a failure in a radio frequency (RF) device (200) that includes a transistor (210) having a first terminal at an RF input (220), a second terminal at an RF output (260), and a third terminal at an RF common (230). The method includes the steps of: detecting a first voltage at the first terminal; comparing the first voltage to a reference voltage; and determining whether the RF transistor (210) is operating in a normal state or a failed state as a function of whether the first voltage falls inside or outside of a predetermined threshold value of the reference voltage.

Abstract: A drive circuit includes a gate voltage detector that detects a gate-emitter voltage Vge that appears between the gate and emitter of a power semiconductor device throughout a detection time period during which a sampler allows the process of detecting the gate-emitter voltage Vge, and that recognizes the occurrence of an abnormality in the power semiconductor device when the gate-emitter voltage Vge exceeds a reference value. Therefore, the drive circuit can protect the power semiconductor device with higher reliability by promptly detecting the occurrence of a short circuit even when the power semiconductor device is resistant to high voltages.

Abstract: An electrical system includes a solid state relay (1) and an electrical connector (2) that connects solid state relay (1) to a load (4). The solid state relay (1) includes a power MOSFET (Q1) for switching power to the load (4). A PNP transistor (Q2) monitors the voltage drop across the power MOSFET (Q1), and shuts the power MOSFET off when the voltage drop exceeds a reference level. The solid state relay circuitry floats when the power MOSFET is commanded OFF so there is no leakage to ground. The relay (1) can be used with an electrical connector that includes a short pin (34) or shunt (16) that is disconnected before male and female terminals (12, 22) are unmated. Disconnection of the shunt (16) or the short pin (34) causes the power MOSFET to be commanded OFF so that there is no current flowing through the male and female terminals (12, 22) when they reach an arc susceptible position. The solid state relay (1) and the connector (2) are suitable for use in a 42 Volt automotive electrical system.

Abstract: An LED drive circuit is disclosed, comprising an electronic controller which is arranged to monitor LED current as a first input. The controller also receives a second input from a sensor associated with the LED. The controller serves to monitor, based on its inputs, at least one further operating parameter of the LED which is either LED junction temperature or LED luminous intensity. The further operating parameter may be directly sensed by the sensor or may be calculated from the inputs to the controller. The controller is adapted to implement a closed loop control on LED current and to thereby limit current as necessary to maintain both the LED current and the further operating parameter below predetermined maximum values.