Abstract: A method, device, and system for detecting a fault for a protective device. The device can receive an input signal and detect a power spike in the input signal. If a power spike is detected in the input signal, the device simultaneously disables the trip mechanism for one or more protective devices and starts a time period. During the remainder of the time period, the device compares the input signal and the threshold value. If, during the remainder of the time period, the input signal exceeds the threshold value, and if the fault originates within a region between the multiple sensing devices, then the trip mechanism for each protective device is again enabled.

Abstract: A data cable between two electronic devices includes a first interface comprising a first metal shell and a ground end; and a second interface connected to another electronic device comprising a second metal shell, a ground end and an identification end. The data cable includes a detection circuit detecting voltage difference between the first metal shell and the ground end, and the detection circuit comprises an output end connected to the identification end of the second interface. An electronic device using the data cable detects any current leakage in an external electronic device. When the host has current leakage, the electronic device cuts power from the host and prevents data exchange, preventing damage or loss.

Abstract: A protective monitoring circuit includes a protective circuit to detect at least one of overcharging, overdischarging, and overcurrent of a chargeable secondary battery to control whether to turn on or off a control transistor to protect the secondary battery, and a secondary-battery monitoring circuit, having a reduced size and having a breakdown voltage lower than a battery voltage of the secondary battery, to detect a status of the secondary battery, wherein the protective circuit generates a voltage that is commensurate with an output voltage of the secondary battery and that is within a predetermined tolerance voltage range of the secondary-battery monitoring circuit, and the secondary-battery monitoring circuit generates a detection value responsive to the generated voltage supplied from the protective circuit, the detection value being indicative of the output voltage of the secondary battery.

Abstract: A protection circuit for a central processing unit (CPU) includes a power circuit, two comparators, a number of resistors, a thermistor, and an electronic switch. A non-inverting input terminal of the comparator is coupled to a first power terminal. An inverting input terminal of the comparator is connected to ground through the thermistor. An output terminal of the comparator is coupled to the electronic switch. When an operation temperature of the CPU exceeds a predefined temperature, the comparator enables the electronic switch to be turned on, to reduce an operation frequency of the CPU.

Abstract: An apparatus for detecting surge voltage and a method thereof are proposed, by which a surge voltage can be detected to prevent damage to output parts by using a shunt regulator, when a surge voltage exceeding a maximum voltage limitable by a zener diode is applied, and trouble shooting and system maintenance/repair of a system can be more effectively performed, the apparatus including a voltage distributor configured to output a driving voltage, when an applied surge voltage exceeds a reference surge voltage, a signal output unit configured to generate an output signal by being driven by a driving voltage outputted by the voltage distributor, and a surge voltage detection signal output unit configured to output a surge voltage detection signal indicating that a surge voltage exceeding the reference surge voltage in response to a signal outputted by the signal output unit.

Abstract: A protection circuit includes an electronic switch and a comparator. The comparator includes a positive input connected to a first power supply, a negative input connected to an output power supply, and an output connected to a first terminal of the electronic switch through a first resistor. A second terminal of the electronic switch is connected to a device. A third terminal of the electronic switch is connected to the output power supply. When a voltage on the positive input is greater than a voltage on the negative input, the comparator outputs a high level signal to turn on the electronic switch, the output power supply powers the device. When the voltage on the positive input is less than the voltage on the negative input, the comparator outputs a low level signal to turn off the electronic switch, the output power supply does not power the device.

Abstract: Voltage instability protection for an electric power system is implemented by determining a change in power injected into a region of interest within the electric power system based on synchronized power measurements from different power injection points of the region of interest, and by determining a change in power absorbed by one or more loads in the region of interest based on synchronized power measurements from different load points of the region of interest. A change in power loss for the region of interest is determined based on the difference between the change in power injected into the region of interest and the change in power absorbed by the region of interest. A voltage instability condition is indicated when the change in power loss for the region of interest approximates the change in power injected into the region of interest.

Abstract: A protection circuit includes an embedded control chip (ECC) which includes detecting pins, each of which is connected with one of working chips of a motherboard to read a working voltage of the working chip, first control pins, each of which is connected with an enable pin of one of voltage chips of a voltage supply module, and a second control pin connected to a power button pin of a Southbridge of the motherboard. Each voltage chip provides an input voltage. Each working voltage is one of the input voltages. The ECC compares each working voltage with an associated standard range, outputs a first abnormal signal to the enable pin of the voltage chip which provides an abnormal working voltage to disable the voltage chip, and outputs a second abnormal signal to the power button pin of the Southbridge to turn off the electronic device.

Abstract: It is presented a gate control circuit comprising: a main gate unit arranged to supply, via a plurality of main gate unit outputs, a gate signal to respective gates of a plurality of power switches, for controlling a main current; and an auxiliary gate unit comprising an optical power converter for converting incoming optical power to an auxiliary electrical gate signal. The auxiliary gate unit is arranged to, when a failure occurs in one of the plurality of power switches, provide the auxiliary electrical gate signal to respective gates of any of the plurality of power switches still being in operation. A corresponding power module and method are also presented.

Abstract: A short-circuit protection circuit of a light emitting diode (LED) is for protecting a plurality of LED strings from a short-circuit condition. The short-circuit protection circuit includes a short-circuit protection unit and a control unit. The short-circuit protection unit is coupled to the plurality of LED strings to execute a short-circuit protection. The control unit coupled to the short-circuit protection unit and the LED strings is configured to control the short-circuit protection unit according to at least one of a feedback voltage and a compensation voltage, so as to determine whether to trigger the short-circuit protection. The feedback voltage is generated from a cross voltage of one of the LED strings, and the compensation voltage is generated according to a comparison result between the feedback voltage and a reference voltage for controlling a power supply of the LED strings.

Abstract: The invention provides a cascode transistor circuit with a main power transistor and a cascode MOSFET formed as an integrated circuit, packaged to form the cascode transistor circuit. A control and protection circuit is integrated into the integrated circuit together and a storage capacitor provides an energy source to drive the control and protection circuit. A charging circuit is also integrated into the integrated circuit for charging the storage capacitor.

Abstract: Exemplary embodiments of the present invention relate to an under-voltage lockout circuit, and a switching control circuit and a power supply including the same. The under-voltage lockout circuit according to an embodiment of the invention includes a first under-voltage lockout circuit comparing a driving voltage with a first reference voltage and a second under-voltage lockout circuit generating an under-voltage lockout signal based on a result of the comparison between the driving voltage and the second reference voltage. The first under-voltage lockout circuit stops operation of the second under-voltage lockout circuit when the driving voltage is lower than the first reference voltage and operates the second under-voltage lockout circuit when the driving voltage is higher than the first reference voltage. Power consumption of the first under-voltage lockout circuit is limited by a first current that generates the first reference voltage.

Abstract: During charging of a cell module in which a plurality of cells are connected in series, a voltage is applied in forward polarity to a switch element even when a current interrupting switch provided to the cell module is open, thereby shorting an anti-fuse element, and the switch element is thereby opened. A voltage monitoring circuit and a vehicle equipped with the voltage monitoring circuit are thereby provided in which a high voltage is not applied even when the cell module is charging when the current interrupting switch is open.

Abstract: There is provided an overheating protection circuit, including a temperature-variable voltage generating unit generating a temperature-variable voltage by adding a temperature-proportional voltage increasing with an increase in temperature and a first turn-on voltage decreasing with an increase in temperature; and an overheating prevention signal generating unit comparing the temperature-variable voltage and a second turn-on voltage decreasing with an increase in temperature to generate an overheating prevention signal, wherein the first turn-on voltage and the second turn-on voltage have the same distribution.

Abstract: A protective monitoring circuit includes a protective circuit to detect at least one of overcharging, overdischarging, and overcurrent of a chargeable secondary battery to control whether to turn on or off a control transistor to protect the secondary battery, and a secondary-battery monitoring circuit, having a reduced size and having a breakdown voltage lower than a battery voltage of the secondary battery, to detect a status of the secondary battery, wherein the protective circuit generates a voltage that is commensurate with an output voltage of the secondary battery and that is within a predetermined tolerance voltage range of the secondary-battery monitoring circuit, and the secondary-battery monitoring circuit generates a detection value responsive to the generated voltage supplied from the protective circuit, the detection value being indicative of the output voltage of the secondary battery.

Abstract: A voltage measuring circuit includes a voltage measuring port, a voltage reference unit, a first voltage comparing unit and a light emitting diode. The voltage measuring port is for receiving an external voltage to be measured. The voltage reference unit includes a port providing a reference voltage. The first voltage comparing unit includes a reference port connected to the voltage reference unit, a measuring port connected to the voltage measuring port, and an output port for outputting a high/low level voltage when the external voltage is lower/higher than the reference voltage. The light emitting diode includes a cathode connected to the output port of the first voltage comparing unit and an anode connected to an external voltage port.

Abstract: Embodiments include systems and methods for detecting and/or responding to deficiencies in power interconnect integrity. For example, a first module distributes power to a second module via a high-current mechanical power interconnect. Insufficient integrity in the interconnect can manifest as an impedance, causing potential thermal hazards. A separate (e.g., low-current) interconnect is used to monitor the power being received by the second module from the first module. Embodiments detect when a difference between the power supplied to and received by the second module exceeds a threshold difference, which can indicate deficient interconnect integrity (i.e., a fault). The supply of high-current power to the second module can be substantially immediately interrupted upon detecting the fault.

Abstract: An apparatus for protecting an electrical network of an aircraft includes a power switch, an activation means coupled with the power switch, and a detection circuit connectable to the electrical network for detecting a voltage. The detection circuit is coupled with the activation means. The activation means is adapted for opening the power switch once the detected voltage is lower than a predetermined voltage. This is particularly advantageous for high voltage direct current networks temporarily, primarily or permanently powered by a fuel cell system.

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 off-line power converter includes an integrated circuit power factor controller including a multi-function input terminal, a drive terminal for providing a drive signal to a gate of a drive transistor, a processing circuit coupled to the multi-function input terminal and, based on a signal received from the multi-function input terminal, providing at least one current signal representative of a current conducted in the off-line power converter, and at least one voltage signal representative of a voltage provided to a load, and a controller for providing the drive signal selectively in response to the at least one current signal and the at least one voltage signal.

Abstract: Method for operating a fail operational power system for a vehicle includes monitoring a first voltage on a first power distribution path and a second voltage on a second power distribution path. An isolator switch controllably operative between open and closed states is monitored. The closed state connects the first and second power distribution paths and the open state opens the connection between the first and second power distribution paths. Each of the monitored first and second voltages is compared to a reference voltage. When a predetermined operating mode requiring fail operational power is enabled, the isolator switch is controlled to the open state when at least one of the monitored first and second voltages violates the reference voltage and the isolator switch is controlled to the closed state when neither one of the monitored first and second voltages violates the reference voltage.

Abstract: A system comprises a battery including one or more cells, an energy source, a load, and a battery protection circuit coupled to the battery, the energy source and the load. The circuit determines if the charge of each cell is at/above a predetermined, band gap supplied threshold voltage, which results in disconnecting of the battery from the energy source. The circuit also may determine if the charge of any cell is at/below a second predetermined level, which may result in disconnecting of the battery from the load. The circuit may be radiation-hardened (e.g., via redundancy), through the use of two sets of field effect transistors, two logic gates, two groups of comparator circuits, and two relays. The circuit provides multiply redundant protection comprising: redundantly assessing the overvoltage determination; redundantly triggering battery isolation; and preventing inadvertent isolation and non-charging, occurring absent overvoltage, through redundant first and second relays.

Abstract: Embodiments include systems and methods for detecting and/or responding to deficiencies in power interconnect integrity. For example, a first module distributes power to a second module via a high-current mechanical power interconnect. Insufficient integrity in the interconnect can manifest as an impedance, causing potential thermal hazards. A separate (e.g., low-current) interconnect is used to monitor the power being received by the second module from the first module. Embodiments detect when a difference between the power supplied to and received by the second module exceeds a threshold difference, which can indicate deficient interconnect integrity (i.e., a fault). The supply of high-current power to the second module can be substantially immediately interrupted upon detecting the fault.

Abstract: A circuit arrangement is disclosed comprising: a normally-on transistor (such as a HEMT) having first and second transistor main terminals and a non-insulated control terminal, the non-insulated control terminal being electrically coupled to a ground; a normally-off switch having first and second switch main terminals and a switch control terminal, the normally-off switch being arranged in a cascode configuration with the normally-on transistor, the first switch main terminal being electrically coupled to the second transistor main terminal, the switch control terminal being electrically coupled to the second switch main terminal and to the ground; and a control circuit configured to switch on the normally-off switch in response to the voltage at the first switch main terminal being negative relative to the ground. A method of controlling such a circuit is also disclosed.

Abstract: An intake/exhaust valve control device for an internal combustion engine including a cylinder having an intake valve and an exhaust valve includes: solenoids for driving at least one of the intake valve and the exhaust valve; a battery for supplying an electric current to the solenoids, a battery state predicting unit for predicting the voltage state of the battery; and an energization start timing setting unit for setting the current carrying start timing of the battery with respect to the solenoids based on the result of the prediction by the battery state predicting unit. According to the intake/exhaust valve control device, since it is possible to obtain the amount of energization necessary for driving the solenoids at an appropriate timing, it is possible to secure the responsiveness of the solenoids.

Abstract: A switching module includes a switching element having a control terminal, electrically connected to a first conduction path including a reference terminal, to be opened and closed by controlling the switching element to be ON and OFF. The switching element is controlled in response to a voltage difference between the reference terminal and the control terminal. Moreover, the switching module includes determining unit that determines whether or not a conduction failure has been occurred between the control terminal and an outside the switching module; and reducing unit that reduces an absolute value of the voltage difference when the determining unit determines that the conduction failure has occurred, so as to forcibly turn OFF the switching element.

Abstract: A semiconductor device is provided for measuring a voltage of each of plural unit cells series-coupled in multi-stage and configuring an assembled battery. The semiconductor device includes two terminals coupled to two nodes which are electrodes of a unit cell and coupled with other unit cells, and a voltage measurement circuit which measures the inter-terminal voltage between the two terminals. The device also includes a down-convert level shifter circuit which converts the inter-terminal voltage into a low-potential-side inter-terminal voltage based on a ground potential, and a comparator circuit which compares the converted low-potential-side inter-terminal voltage with a predetermined reference voltage.

Abstract: An overcharge protection device (OPD) is provided that may be used alone, or in combination with conventional charging protection systems, to protect a battery pack from the occurrence of a potentially damaging overcharging event. The OPD is designed to be coupled to, and interposed between, the terminals of the battery pack. During normal system operation, the OPD has no effect on the operation of the charging system or the battery pack. During an overcharging event, if overcharging is not prevented by another conventional system, the OPD of the invention creates a short across the terminals of the battery pack causing a battery pack fuse designed to provide battery pack short circuit protection to blow, thereby interrupting the current path from the charger to the battery pack and preventing the battery pack from being overcharged.

Abstract: A description is given of a method for the pulsed control of a transistor which has a control terminal and a load path. The load path of the transistor is connected in series with a load. A control circuit is provided for a transistor. In the method, the transistor is controlled with a control pulse of a first type, which has a first control level at least for a first time duration, before a control pulse of a second type, which has a second control level, which is higher in comparison with the first control level. A voltage across the load path of the transistor is evaluated and the pulsed control is terminated if the voltage across the load path exceeds a predefined threshold value.

Abstract: A first voltage dividing circuit is connected between a power feeding line to feed power from an external power supply to an internal circuit, and a fixed potential to divide a voltage of the power feeding line. A first comparator compares a divided voltage, which has been divided by the first voltage dividing circuit, with a reference voltage, and outputs a signal to turn off a power switch inserted into the power feeding line when the divided voltage exceeds the reference voltage. A first transistor is connected between a first node where the divided voltage, which has been divided by the first voltage dividing circuit, is generated, and the fixed potential, and is turned on when the voltage of the first node exceeds a set voltage.

Abstract: A by-pass circuit includes a first power MOS with an intrinsic diode, a first conduction terminal coupled to a cathode, a second conduction terminal coupled to an anode, and a control terminal. A tank capacitor is coupled to the anode. A second MOS has a first and second conduction terminals, a control terminal, and a turn-on threshold smaller than that of the intrinsic diode, the first conduction terminal thereof coupled to the cathode and the control terminal coupled to the anode, so the first MOS turns on when the array of cells are sub-illuminated. An oscillator and charge pump are supplied through the second conduction terminal of the second MOS to charge the tank capacitor. A control circuit is coupled to the control terminal of the first power MOS to switch it based upon a voltage of the tank capacitor and sign of the voltage between the cathode and anode.

Abstract: A power supply system has a power storage device and an ECU, and supplies driving electric power to a load device. The power storage device includes an interrupting device configured to interrupt a conduction path of the power storage device. The load device includes a voltage sensor for detecting a voltage applied to the load device, and supply of electric power from the load device to the power storage device is stopped in response to a failure of the voltage sensor. Where the voltage sensor has failed, the ECU determines presence or absence of activation of the interrupting device, based on a variation length of an actual current that is input to or output from the power storage device and a variation length of a command current set in accordance with requested electric power requested based on a user's operation.

Abstract: A safe disconnect circuit is provided for mitigating the effect of harmful circuit conditions upon a load, such as an integrated power module (IPM). The safe disconnect circuit comprises a switching circuit operative to receive a pulsed input signal, and to detect the presence of a load threatening input signal, e.g. a load control signal, having an amplitude below a preset amplitude threshold and a duration beyond a present duration threshold. The switching circuit is operative to terminate load power in response to detect a presence of the load threatening signal.

Abstract: An overvoltage battery protection circuit includes a voltage comparator configured to compare a scaled version of a voltage with a voltage reference and indicate an overvoltage condition when the scaled voltage exceeds the voltage reference. The voltage comparator is powered by a first voltage domain. The circuit further includes a first transistor coupled to an output of the voltage comparator and configured to turn on when the voltage comparator indicates the overvoltage condition and generate an overvoltage signal for at least one external device. The circuit further includes a second transistor coupled to the overvoltage signal and configured to turn on when the overvoltage signal is asserted and force the overvoltage signal to remain asserted independent of the first voltage domain. The first and second transistors are powered by a second voltage domain.

Abstract: A controller identifies a condition of a hazardous internal short by comparing patterns of series element voltages to the last known balance condition of the series elements. If the loaded or resting voltage of one or more contiguous series elements uniformly drop from the previously known condition by an amount consistent with an over-current condition, an over-current internal short circuit fault is registered. The desired response is to prevent the affected series elements from heating to a hazardous temperature by summoning the maximum heat rejection capability of the system until the short ceases and the affected elements cool, the cooling function is no longer able to operate due to low voltage, or the affected series string has drained all of its energy through the short. Also includes are responses that allow the battery pack to continue to power the cooling system even though it may enter an over-discharged state.

Abstract: A method is used to monitor a disconnection device of a battery system having a battery with a plurality of battery cells. The method includes using a monitoring device, which is connected to the disconnection device, to detect a negative voltage or a positive voltage which is applied to connections of the disconnection device. The method also includes evaluating the detected applied negative voltage or positive voltage to establish a functional state of the disconnection device. The method also includes initiating measures to protect the battery system against manipulation of its disconnection device when a value of detected applied negative voltage or positive voltage exceeds a predetermined threshold value.

Abstract: An overvoltage detection system includes a sensed voltage; an active reference module that generates an active reference signal having a magnitude that varies inversely with a magnitude of the sensed voltage; and a timed trip module that includes a resistor and capacitor, and detects an overvoltage condition as a function of the sensed voltage, the active reference signal, and time.

Abstract: A transmitter/receiver circuit includes secondary batteries connected in series, a first protection circuit in a high voltage side of the secondary batteries and including a transmitter circuit increasing a voltage of a binary signal to a level that is a first voltage higher than an anode voltage of a first secondary battery connected to the first protection circuit, and a second protection circuit in a low voltage side of the secondary batteries and including a receiver circuit that receives the binary signal from the transmitter circuit via a wiring and including a shift part decreasing the voltage of the binary signal to a level that is a second voltage lower than a cathode voltage of a second secondary battery connected to the second protection circuit, and a detection part that determines that the wiring is disconnected when the voltage of the binary signal is lower than a reference voltage.

Abstract: Installation (100; 100?) comprising two batteries joined in parallel with the aid of a first device (1; 1?) for protection of a voltage source (10; 20), comprising: a parallel assembly comprising a controlled breaker (5; 52, 53) and a resistive element (4; 42, 43), a coil (3) arranged in series with the said assembly between, the two batteries, a means (6) of control of the breaker of the said assembly controlled as a function of the voltage difference (V_AB) between the two batteries so that the controlled breaker is closed when the voltage difference becomes less than a first threshold (threshold 1) and that the controlled breaker is open when the voltage difference becomes greater than a second threshold (threshold 2).

Abstract: In the present invention, a main switch circuit (13) is provided between an electric power line (PL), to which voltage outputted from a solar cell (11) is applied, and a battery module (12). A protection circuit (19) turns OFF the main switch circuit (13) to protect the battery module (12) from overcharging when the voltage (VBAT) of the battery module (12) is equal to or greater than an upper limit voltage. The voltage outputted from the solar cell (11) is set so as to be greater than the upper limit voltage to allow the battery module (12) to be charged to the upper limit voltage. When a charge ON command signal has been received, a control unit (18) turns ON only a sub-switch circuit (14) to introduce current from the solar cell (11) into a parallel circuit (15) and to suppress the voltage (VPL) of the power line (PL) to less than the upper limit voltage before turning ON the main switch circuit (13).

Abstract: An apparatus (100) for protecting a circuit (200) from an input volume comprises a switchable element (10) arranged to couple the input voltage (VIN) to the circuit (200) in response to a first control signal (DRV1) having a first value and to decouple the input voltage (VIN) from the circuit (200) in response to the first control signal (DRV1) having a second value. A monitor stage (20) compares a monitored voltage (VMON) to a threshold (VIN). A controller (30) provides the first control signal (DRV1) to the switchable element (10), the first control signal (DRV1) having the first value when the monitored voltage (VMON) is on one side of the threshold (VTH), wherein the first value is independent of the input voltage (VIN) and the second value is equal to the input voltage (VIN).

Abstract: Power handling circuits that may be packaged as power modules, and methods of operating semiconductor devices in such circuits and modules. An exemplary circuit comprises power terminals to receive electrical power, a first semiconductor device, a first drive circuitry, and a second drive circuitry. The first drive circuitry provides a drive signal to the first semiconductor device in accordance with a desired circuit function when the electrical power received at the power terminals has the positive polarity, and ceases providing the drive circuit when the electrical power received at the power terminals has the negative polarity. During the negative polarity condition, the second drive circuitry provides a drive signals to the first semiconductor device which causes its primary current conduction path to conduct, thereby reducing the power dissipation in the device's parasitic path, and optionally causing a fuse in the circuit providing power to the circuit to blow.

Abstract: In general terms, embodiments of the present invention relate to an overvoltage protection circuit. In some embodiments, the overvoltage protection circuit includes: (a) an input receiving node configured to receive an input voltage; (b) an input transmitting node; (c) an input switch formed between the input receiving node and the input transmitting node, and configured to selectively electrically connect the input receiving node to the input transmitting node based on a switch control signal, where the input switch is configured to cut off an electrical connection between the input receiving node and the input transmitting node when the switch control signal is in an inactive state (e.g., a logic low state “L”); and (d) a control signal generation block configured to sense a transmission voltage of the input transmitting node and generate the switch control signal in the inactive state when the transmission voltage rises to a reference voltage or higher.

Abstract: A service line safety monitor which may be configured as a separate module or incorporated into an EVSE is adapted to monitor the connection with the service line to determine whether there is a defect in the connection. The module preferably employs a current transformer to determine a no-load and a load applied to the EVSE. Comparisons are made to determine whether there is a power loss. In the event of a power loss beyond a safe limit, the monitor disconnects the EVSE from the service line. A warning indicator is also employed.

Abstract: A circuit arrangement is disclosed comprising: a normally-on transistor (such as a HEMT) having first and second transistor main terminals and a non-insulated control terminal, the non-insulated control terminal being electrically coupled to a ground; a normally-off switch having first and second switch main terminals and a switch control terminal, the normally-off switch being arranged in a cascode configuration with the normally-on transistor, the first switch main terminal being electrically coupled to the second transistor main terminal, the switch control terminal being electrically coupled to the second switch main terminal and to the ground; and a control circuit configured to switch on the normally-off switch in response to the voltage at the first switch main terminal being negative relative to the ground. A method of controlling such a circuit is also disclosed.

Abstract: The present invention provides an apparatus for easily detecting an abnormal status of power generation of a solar cell panel in a solar cell power generation system having the power generation of 1 MW or higher. The present invention provides an abnormality detecting apparatus for a solar cell power generation system including a plurality of solar cell strings each having a plurality of solar cell modules connected to each other in series and a backflow preventing diode connected to a power output terminal of each of the solar cell strings, characterized in that the abnormality detecting apparatus further includes measuring means for measuring a current flowing in the backflow preventing diode; and that the measuring means is supplied with electric power from both terminals of the backflow preventing diode.

Abstract: Apparatus for protecting a signal line bus driver from overvoltage faults may include a first solid-state switch configured to block current having a positive voltage when open and a second solid-state switch configured to block current having a negative voltage when open. A comparator circuit may produce a output signal responsively to presence of a fault-induced voltage in the signal line that has a magnitude that exceeds the reference voltage. The first and second switches may be connected in series with one another and with the bus driver. The switches may be interposed between the bus driver and an output end of the signal line and may responsively to the comparator circuit output signal.

Abstract: A protection circuit includes a switch circuit, a sample circuit, a comparison circuit, and a relay circuit. The switch circuit is connected between a hard disk power supply and a hard disk to control whether to output power from the hard disk power supply to the hard disk. The sample circuit samples the voltage being supplied to the hard disk, the comparison circuit receives the sampled voltage, compares the sampled voltage to a reference voltage, and controls the switch circuit to be turned on or off accordingly. The relay circuit is connected between a system power supply and an enable terminal of the comparison circuit. The relay circuit outputs a high level signal to turn on the switch circuit when the system power supply is being supplied and the hard disk power supply is not being supplied to the hard disk.

Abstract: Methods, systems, and apparatus for determining whether an accessory includes particular circuitry. A host device may measure a first voltage and a second voltage received from an accessory, where the voltages are provide through the accessory from a power source. Before measuring the second voltage, the host device may send an instruction to the accessory instructing the accessory to alter an impedance of the power path between the power source and the host device, and the host device may draw at least a threshold amount of current from the power source via the accessory. The host device may then determine whether the accessory includes particular circuitry based on the relationship between the first voltage and the second voltage.

Abstract: A semiconductor device may be protected from over-voltages via a comparator-controlled, high-current FET coupled to the semiconductor device output and between circuit devices that carry high voltages. A three-terminal, N-channel field effect transistor (FET) may have its source coupled to the output of the semiconductor device to be protected from over voltage. The FET drain may be connected to the load to be driven by the semiconductor device. A transistor, or other voltage comparator, may be configured and connected in order to compare the voltage on the FET drain to a Vmax reference voltage. When a voltage on the FET drain exceeds Vmax, the comparator output may shut down the FET, thereby isolating the semiconductor device, which is connected to the FET source, from the overvoltage on the FET drain.