Abstract: A high-side output transistor and a low-side output transistor of an output circuit control voltages of conductors, which connect a power supply terminal and ground, and outputs a voltage signal to an output terminal through an output conductor. A voltage output circuit detects a voltage applied to the high-side output transistor based on a potential difference of a first resistor provided closer to the output terminal side. A comparator circuit outputs a signal to turn off a first switch and a second switch provided in the conductors, when the output voltage of the voltage output circuit exceeds a reference voltage Vr.

Abstract: Apparatus and methods for selective protection of an electrical load from disturbances on an input power line. A power protection circuit includes a selectively variable inrush current limiting circuit and a switch for disconnecting the input power line from the load. A control circuit determines that the electrical load is in a first operational state, such as a standby mode or normal operation, or a second operational state, such as full operation at rated current. The power protection circuit provides variable inrush current limiting to the electrical load in response to a first category of disturbances when the electrical load is in the first operational state. The power protection circuit inhibits disconnecting the electrical load in response to a second category of disturbances when the electrical load is in the second operational state. Species of selectively variable current limiting circuits are also described.

Abstract: A circuit comprises a first conductor, a second conductor, and a first detect and disconnect circuit. The first conductor is coupled to a first power supply voltage terminal. The second conductor is positioned a first predetermined distance from the first conductor. The first detect and disconnect circuit has a first terminal coupled to the second conductor and a second terminal coupled to a second power supply voltage terminal. The first detect and disconnect circuit detects a first electrical property change between the second conductor and the first conductor. In response to detecting the change in the first electrical property, the second conductor is disconnected from the second power supply voltage terminal. A method for manufacturing a semiconductor device comprising the circuit is also provided.

Abstract: A system for autonomous protection from fires and electrical shock of components used in construction of photovoltaic arrays is disclosed. The system detects conditions that left unattended will result in conflagration of combustible materials and unwanted electrification. The disclosed system provides an active control mechanism that operates to take defective components off line and thus provide protection from fire and electrification hazards that otherwise could arise. The system also provides means for annunciation and notification when actions are taken. The system can be used, for example, to determine that a photovoltaic (PV) module is at risk of conflagration of its flammable structural elements due to intense heat of plasma produced by a direct current (DC) arc at a point in the grid of conductors that collect and carry current from photovoltaic cells exposed to solar irradiation.

Abstract: A method, device, and system for mitigating the effect of a power spike on a protective device. The device can receive an input signal and determine whether the input signal exceeds a threshold value. If so, the device simultaneously starts an initial time period and starts a latch time period, where the latch time period is greater than the initial time period. During the initial time period, the device replaces the input signal with a set value signal. After the initial time period ends and during the remainder of the latch time period, the device prevents the input signal from being replaced by the set value signal. If, during the remainder of the latch time period, the input signal exceeds the threshold value, a trip signal may be generated by a protective device.

Abstract: An electronic device includes a port for connecting the electronic device to other electronic devices and a moisture detector configured to detect an electrically conductive liquid in the first port. The moisture detector is configured to maintain a voltage on a first electrical contact of the port and to detect a short circuit between the first electrical contact and a second electrical contact of the port. The moisture detector determines that the electronic device has been exposed to an electrically conductive liquid if the monitor module detects the short circuit. The moisture detector may also put the electronic device into safe mode if it is exposed to an electrically conductive liquid.

Abstract: When a short-circuited FET is identified as one of low-side FETs, maximum phase voltages of three phases are detected when a steering operation is performed by a driver, and the detected maximum phase voltages of the three phases are compared with one another to identify a short-circuit phase. On the other hand, when a short-circuited FET is identified as one of high-side FETs, minimum phase voltages of the three phases are detected when a steering operation is performed by the driver, and the detected minimum phase voltages of the three phases are compared with one another to identify a short-circuit phase.

Abstract: Disclosed herein is a device that protects against electrical shock hazards involving two circuit conductors. The device continuously evaluates the load characteristics of electrical equipment and automatically provides feedback on status and changes of such equipment. The device has a “learning mode” wherein it stores the load characteristics of loads connected to the device. The device also has an “protection mode” (or “normal mode”) wherein the devices compares connected load characteristics to stored load characteristics, and based on this comparison determines if an electrical fault is present. If the device determines that an electrical fault is present, the device then takes action to protect against electrical shock, such as by disconnecting the system from power.

Abstract: A modular power distribution system comprises a chassis; and a backplane including a power input, and a plurality of module connection locations. A plurality of modules are mounted in the chassis, each module mounted to one of the module connection locations. Each module includes: (i) an OR-ing diode; (ii) a circuit protection device; (iii) a microprocessor controlling the circuit protection device; and (iv) a power output connection location. A circuit option switch is located on each module for setting the current limits for each module. A control module is provided connected to the backplane.

Abstract: A method and an arrangement are disclosed for detecting islanding operation of a distributed power generator. The method can include determining a frequency of a grid to which the distributed power generator is connected, measuring a rate of change of the frequency of the grid at an output of the distributed power generator, determining a threshold value for an alteration speed, comparing the rate of change of the frequency of the grid with the threshold value, and detecting islanding operation when the measured rate of change of the frequency exceeds the threshold value for a certain time period.

Abstract: A protection relay for protecting an electric system, includes means a manner of a time multiplier value, a manner of calculating, with the received time multiplier value, and an inverse definite time dependency having an exponentiation function. The dependency defines a relationship between an excitation level of an input signal to the relay and an operating time of the relay. The relay further a manner of shifting the dependency to a predefined calculation space, and includes a manner of applying, during execution, the dependency shifted to the predefined calculation space when determining an operating condition of the relay.

Abstract: For a system to avoid abnormal operation caused by a shorted parameter setting pin of an integrated circuit, a protection apparatus and method apply a buffered reference voltage to the parameter setting pin to define an internal parameter of the integrated circuit by the buffered reference voltage and an external element connected to the parameter setting pin, and detect the rapid variation of the internal parameter to trigger a shutdown signal or slow down the speed of the variation of the internal parameter reflected to an adjustable signal of the integrated circuit.

Abstract: An electronic circuit breaker includes controllable mechanical contacts adapted to connect a primary power source to at least one load; and control circuitry for monitoring the flow of power from the primary power source to the load, detecting fault conditions and automatically opening the contacts in response to the detection of a fault condition. A primary power source supplies power to the control circuitry when the contacts are closed, and an auxiliary power source supplies power to the control circuitry when the contacts are open, whether by a trip or by manual opening.

Abstract: The present invention relates to methods for providing impedance protection differentiating between in-zone and out-of-zone faults based on instantaneous, digitally derived operating and polarizing distance comparator signals. The method uses a pair of fast orthogonal filters to derive D and Q components of the input voltages and currents. Two sets of operating and polarizing signals are derived for better speed of response under varying fault moment with respect to the peaks and zero crossings of power signals. Three stages of comparison between the operating and polarizing impedance terms are used. These comparator stages use half a cycle averaging windows, and three-quarters-of-a-cycle windows. The first stage of comparison is based on energy comparator responding to both magnitude and phase information in the signals. Stages 2 and 3 are of phase comparison type, responding mostly at the phase information and neglecting the magnitude information for better immunity to noise and signal distortions.

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 voltage activated 2nd level safety circuit for permanent isolation having a current activated fuse useful for class III medical devices, military applications, and any other passive loads. The battery system has a fuse current limiter and the current activated fuse maintain the fuse closed when a power cell, having a current sufficient to blow the fuse expeditiously, directs its current to the load. The power cell continues to direct its current to the load until the system detects an unacceptable battery or circuit condition. Once that unacceptable condition exists and is detected, a fuse blowing circuitry allows the power cell's current to expeditiously blow the current activated fuse. In response to the blown current activated fuse, the system's isolation switch(es) open as well to establish a permanent isolated battery.

Abstract: A protection circuit includes a coding chip, a digital-to-analog converter (DAC), and a control circuit. The coding chip receives parallel voltage identification definition (PVID) signals or serial voltage identification definition (SVID) signals from a central processing unit (CPU), and converts the PVID signals or the SVID signals to voltage identification definition (VID) signals. The DAC receives the VID signals from the coding chip, and converts the VID signals to an analog voltage. The control circuit receives the analog voltage from the DAC and a voltage received by the CPU, and compares the analog voltage from the DAC with the voltage received by the CPU. When the voltage received by the CPU is greater than the analog voltage from the DAC, the control circuit disconnects the CPU from a first power supply.

Abstract: A test device includes a transformer, a loop analyzer, and a protection circuit. The protection circuit includes a control unit, a signal acquisition and amplification unit, and an electronic switch. When the loop analyzer outputs a signal, the signal acquisition and amplification unit acquires the signal output from the loop analyzer, amplifies the acquired signal, and outputs the amplified signal to the control unit. The control unit transforms the received signal from analog form to digital form, and compares the digital signal with a reference value. If the digital signal is greater than the reference value, the control unit outputs a control signal to the electronic switch, to turn off the electronic switch. The signal output from the loop analyzer cannot be transmitted to a buck circuit.

Abstract: A method of controlling a protection relay, includes inputting an input characteristic quantity and determining a triggering condition for the protection relay using a calculation equation, the value of which increases when the input characteristic quantity exceeds a first threshold value, and decreases when the input characteristic quantity undershoots a second threshold value for an overfunction measure, and the value of the calculation equation increases when the input characteristic quantity undershoots a first threshold value, and decreases when the input characteristic quantity exceeds a second threshold value for an under function measure, wherein the calculation equation includes a first measure and a second measure, and the triggering occurs when the first measure is greater than the second measure.

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: Provided is a battery system capable of preventing the voltage that is applied to the voltage detection circuit from exceeding the withstand voltage of the voltage detection circuit when the connection between the cells in the battery module is disconnected, and preventing an overcurrent from flowing in the cell voltage detection circuit and the module. The modules are internally provided with a battery voltage measurement circuit 2 for measuring the voltage of each cell. A reverse voltage protective diode 3 is disposed in the power supply route of the battery voltage measurement circuit 2, and adapted such that the anode thereof is connected to the negative electrode of a drive power source of the voltage measurement circuit and the cathode thereof is connected to the positive electrode of the drive power source of the voltage measurement circuit. A fuse 4 as an overcurrent protective element is provided to the power supply route of the battery voltage measurement circuit 2.

Abstract: An apparatus for an electric power tool includes a detection unit, a determination unit, a protection unit, a calculation unit, and a notification unit. The calculation unit calculates a time-equivalent value representing a remaining time until a load condition of a battery reaches an overload state, in which the protection unit interrupts a discharge path, based on the result of the detection by the detection unit. The notification unit notifies a user of the electric power tool of a remaining time until the protection unit interrupts the discharge path based on the time-equivalent value calculated by the calculation unit.

Abstract: A hybrid switch circuit includes a hybrid switch that couples an input conductor connected to an AC power supply to an output conductor connected to a load. The hybrid switch includes a power semiconductor in parallel with an electromagnetic relay. A control circuit turns on the hybrid switch by turning on the power semiconductor at a zero-voltage crossing of the AC voltage to provide a conductive path and then closing the relay to provide a conductive bypass path that bypasses the power semiconductor. The control circuit turns off the hybrid switch by opening the relay and subsequently turning off the power semiconductor at a zero crossing of the load current. The control circuit operates in response to a hybrid switch control signal that indicates whether an operating fault condition exists.

Abstract: A method and a device for supervising the sensitivity of a protection function in an electrical power system including a metering device for measuring values of a feature, said protection function being configured to initialize an action based on a test value and a threshold value for the feature, wherein said test value is either a measured value or derived from the said measured values, the device includes a computing unit configured to receive the test values and, repeatedly during the operation of the protection function, to calculate a mean value and a deviation of the test values, to determine the probability of a false action based on the calculated mean value, the threshold value and the calculated deviation, and to indicate that the sensitivity is too high when the probability of a false action exceeds a first limit value for the probability of a false action.

Abstract: A method of monitoring a capacitor bank comprising a plurality of capacitor strings connected in parallel, each capacitor string comprising a plurality of capacitors connected in series is provided. The method includes energizing the capacitor bank. The method includes determining dissipation factors of each of the plurality of the capacitor strings. The method further includes comparing each of the determined dissipation factors with an expected dissipation factor and estimating a health state of the plurality of the capacitor strings based, at least in part, on the comparison of the determined and expected dissipation factors.

Abstract: An output termination board for a safety system is disclosed herein. The termination board provides simplified wiring between the output modules and the remote devices operated by the controller in the system. Redundant output signals are generated within each pair of output modules and combined such that one control signal is sent to each remote device. In addition, a program executing on the controller of the safety system performs a test to determine if each output module is operating normally. If the program detects a fault in either output module, the safety system may alternately shut down according to a fail-safe procedure or continue operating under a fault-tolerant mode of operation.

Abstract: A device includes interface circuitry. The interface circuitry receives first input signals related to measurements of characteristics of electricity passing through a first power line. The device includes filtering circuitry that filters the first input signals to generate filtered data. The device also includes a processor that estimates an oscillation frequency of the filtered data via a time-domain frequency estimation method.

Abstract: The present invention is directed to a protective relay for providing protective control to a power system carrying three-phase power. The protective relay performs a faulted phase detection method wherein signal values representative of electrical properties of the power carried by the power system are received and are processed to produce processed signals, respectively. The processed signals have components of the signal values removed that are the same frequency as the nominal operating frequency of the power system. The process signal values are added to produce a sum, which is then divided by a predetermined number to yield a quotient. A determination is made whether the quotient falls within one of a plurality of predetermined ranges. This determination is used to determine whether the power system has a single-phase fault, a two-phase fault, or a three-phase fault.

Abstract: A protection system includes a baseboard management controller (BMC), N fans, a power on unit, a power supply, and a switching unit. The switching unit includes an AND gate, a transistor, and a first resistor. During operation the fans each output an operating signal to the BMC. The BMC counts the operating signals received. When the count is less than N, the power-off pin outputs a low level signal, so that the output pin of the AND gate outputs a low level signal, and the transistor turns off. The power supply then receives a high level signal and stops supplying power.

Abstract: A method of determining out of step condition and an instance of separation within electrical power system. The method does not require user settings and ensures reliable discrimination between recoverable power swing and pole slips that indicates non-recoverable power swing and the need for system separation. The method also allows tripping at a user selected system angle if desired. A calculated angle is used to determine the magnitude of the swing current to control the tripping at the desired angle ? when the system could be safely split after detection of out of step condition based on the criteria of this invention.

Abstract: A robot system including a robot arm driven by a servo motor; and a robot controller controlling an operation of the robot arm. The robot system further comprises a first detection section detecting a rotation amount of the servo motor; a second detection section attached to a tip portion of the robot arm, and detecting a velocity or acceleration of the tip portion of the robot arm; a computation section computing the velocity or acceleration of the tip portion of the robot arm based on values detected by the first detection section, and computing a deviation between this computed velocity or acceleration and the velocity or acceleration detected by the second detection section; and an emergency stop section for bringing the servo motor to an emergency stop when a magnitude of the deviation computed by the computation section is greater than a reference value.

Abstract: A power supply circuit identification device for identifying a type of a power supply circuit, the power supply circuit having an input terminal to which a control signal for controlling electrical power supplied to an electrical load is input and an output terminal from which a detection signal that indicates whether the electrical power corresponding to the control signal is supplied to the electrical load is output, at least one of the input terminal and output terminal being plurally provided and having a type-dependent correlation between the input and output terminals. The identification device includes: a control section configured to input the control signal to the power supply circuit via the input terminal; a reading section configured to read the detection signal from the output terminal; and an identification section configured to identify a type of the power supply circuit based on a reading result from the reading section.

Abstract: An integrated circuit chip including a plurality of parallel wells of alternated conductivity types formed in the upper portion of a semiconductor substrate of a first conductivity type, and a device of protection against attacks including: between the wells, trenches with insulated walls filled with a conductive material, said trenches extending from the upper surface of the wells to the substrate; and a circuit capable of detecting a modification of the stray capacitance formed between said conductive material and a region of the chip.

Abstract: A thermal cutoff circuit for an electronic device including a power unit, a thermal sensor, a logic unit, and a power switch unit is provided. The power unit includes a power switch for powering up the thermal cutoff circuit with a supply voltage in response to a user event. The thermal sensor provides an active thermal sense signal and an inactive thermal sense signal when a temperature of the electronic device exceeds a threshold and does not exceed the threshold, respectively. The logic unit provides an inactive cutoff signal and provides an active cutoff signal respectively according to the inactive thermal sense signal and the active thermal sense signal. The power switch unit powers the electronic device up according to the inactive cutoff signal and stops powering up the electronic device according to the active thermal sense signal.

Abstract: A protection relay for protecting an electric system, includes means a manner of a time multiplier value, a manner of calculating, with the received time multiplier value, and an inverse definite time dependency having an exponentiation function. The dependency defines a relationship between an excitation level of an input signal to the relay and an operating time of the relay. The relay further a manner of shifting the dependency to a predefined calculation space, and includes a manner of applying, during execution, the dependency shifted to the predefined calculation space when determining an operating condition of the relay.

Abstract: Embodiments of the invention relate to drivers and methods for driving devices, comprising at least one functional unit at least one of which is adapted to deduce a device parameter of an electronic device from a terminal parameter of the electronic device.

Abstract: A semiconductor switch control device includes a current detecting unit that detects a current that flows in a semiconductor switch, a voltage detecting unit that detects a voltage, and a temperature detecting unit that detects a temperature. A transient thermal resistance value providing unit provides a transient thermal resistance value Zth in accordance with an elapsed time from reception of an excess voltage signal to a computing unit. A temperature detecting unit detects an initial temperature TJ0 when an excess voltage is produced. The computing unit calculates a temperature of the semiconductor switch by a following expression when a detected current value is represented by Ids, and a detected voltage value is represented by Vds: (expression): temperature of the semiconductor switch TJ=Ids×Vds×Zth+TJ0.

Abstract: An apparatus for an electric power tool includes a detection unit, a determination unit, a protection unit, a calculation unit, and a notification unit. The calculation unit calculates a time-equivalent value representing a remaining time until a load condition of a battery reaches an overload state, in which the protection unit interrupts a discharge path, based on the result of the detection by the detection unit. The notification unit notifies a user of the electric power tool of a remaining time until the protection unit interrupts the discharge path based on the time-equivalent value calculated by the calculation unit.

Abstract: A photovoltaic module including a plurality of single photovoltaic cells is described. The photovoltaic module includes an electric connection device having power connections for outputting generated photovoltaic energy to a consumer network and an electric cutout device having cutout terminals at the power connections of the electric connection device and at least one safety circuit breaker through which the power connections of the electric connection device may be disconnected electrically from the consumer network. The electric cutout device includes a trigger device which is formed with a thermal sensitivity and/or a smoke sensitivity, which is connected to the safety circuit breaker in such a way that upon detection of a temperature and/or of smoke exceeding a predetermined threshold, the safety circuit breaker electrically disconnects the power connections of the electric connection device from the consumer network. A combination of several such photovoltaic modules is also described.

Abstract: The present invention is directed to an electrical wiring device that includes at least one user accessible input mechanism and a test assembly configured to initiate a self-test in response to stimulus signal. The self test determines whether a sensor, a fault detection circuit or a circuit interrupter assembly are in an operational mode or are in a failure mode, the reset stimulus being provided in the operational mode and a reset lockout stimulus being provided in the failure mode. The device also including a reset lockout mechanism coupled to the circuit interrupter assembly and the test assembly. The reset lockout mechanism is configured to disable the reset stimulus in response to the reset lockout stimulus if any one of the at least one sensor, at least one fault detection circuit, or circuit interrupter assembly is determined to be in the failure mode after a predetermined time elapses.

Abstract: A lightning strike detector that can promptly detect a lightning strike to ensure safety and can accurately determine the position struck by the lightning with a simple, inexpensive, and highly reliable structure, is provided. The lightning strike detector includes an environment-detecting sensor member that detects a change in the environment of the internal space of a wind turbine blade, serving as a hollow structure, when the wind turbine blade is struck by lightning and is damaged, converts the environmental change into an electrical signal, and outputs the electrical signal; and a control unit (nacelle-side control system and ground-side control system) that receives the electrical signal, judges whether a lightning strike has occurred, and takes countermeasures against the lightning strike.

Abstract: A battery system utilizes a plurality of transformers interconnected with the battery cells. The transformers each have at least one transformer core operable for magnetization in at least a first magnetic state with a magnetic flux in a first direction and a second magnetic state with a magnetic flux in a second direction. The transformer cores retain the first magnetic state and the second magnetic state without current flow through said plurality of transformers. Circuitry is utilized for switching a selected transformer core between the first and second magnetic states to sense voltage and/or balance particular cells or particular banks of cells.

Abstract: An input termination board for use with an industrial controller in a safety system is disclosed herein. The industrial controller may be populated with standard analog input modules according to the requirements of the application. The termination board may selectively receive a single analog input signal from a remote device and transmit the signal to corresponding channels on two analog input modules or, alternately, receive two analog input signals and transmit each signal to one of the two corresponding channels. In addition, a program executing on the controller of the safety module monitors and tests each of the analog input channels on the input modules, verifying proper operation of the modules. If the program detects a fault in either input module, the safety system may alternately shut down according to a fail-safe procedure or continue operating under a fault-tolerant mode of operation.

Abstract: An inverter driver controls an inverter that supplies driving voltages to a plurality of discharge lamps. The inverter driver senses the abnormal operation of the plurality of discharge lamps based on a plurality of first feedback voltages corresponding to the plurality of driving voltages supplied to the discharge lamps and a plurality of second feedback voltages corresponding to the current flowing through the plurality of discharge lamps. The inverter driver is formed in a single integrated circuit.

Abstract: Fault interrupting devices and methods for controlling the same are disclosed. The fault interrupting devices may include a switch on an electrical power line and a controller configured to operate the switch. The methods for controlling fault interrupting devices may include gathering data, determining from the data that a fault has occurred, opening the fault interrupting device to interrupt the fault, analyzing the data, and determining whether the fault interrupting device can be reclosed based at least partially on the analysis of the data.

Abstract: A method and a device for supervising the sensitivity of a protection function in an electrical power system including a metering device for measuring values of a feature, said protection function being configured to initialize an action based on a test value and a threshold value for the feature, wherein said test value is either a measured value or derived from the said measured values, the device includes a computing unit configured to receive the test values and, repeatedly during the operation of the protection function, to calculate a mean value and a deviation of the test values, to determine the probability of a false action based on the calculated mean value, the threshold value and the calculated deviation, and to indicate that the sensitivity is too high when the probability of a false action exceeds a first limit value for the probability of a false action.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A first semiconductor switching element connects to a high side of a motor and includes a diode whose cathode faces the high side. A second semiconductor switching element having a diode resides on a low side of the first semiconductor switching element. A third semiconductor switching element having a diode resides on a low side of the motor. A fourth semiconductor switching element is connected in parallel to the motor and configures a return current circuit that includes a return current element and causes a return current that arises when the first semiconductor switching element turns off to flow through the return current element. A control portion controls on-off states of the first to the fourth semiconductor switching elements and performs return current circuit failure detection based on a first monitor voltage that is an electric potential of a connecting point between the first semiconductor switching element and the motor.

Abstract: An input termination board for use with an industrial controller in a safety system is disclosed herein. The industrial controller may be populated with standard input modules according to the application. The termination board, in conjunction with the controller allows the standard input modules to be used as safety inputs. The termination board provides simplified wiring between the input modules and the remote devices by splitting each of the signals generated by the remote device into separate inputs for two different input modules. In addition, a program executing on the controller of the safety system monitors and tests each of the inputs in both input modules to verify proper operation of the inputs. If the program detects a fault in either input module, the safety system may alternately shut down according to a fail-safe procedure or continue operating under a fault-tolerant mode of operation.

Abstract: Devices and methods for preventing shock from a high voltage power source. In one embodiment, a device for preventing an electric shock, comprises output terminals for connecting to an external load, a low voltage circuit for carrying a first current (IL) to the output terminals, the low voltage circuit comprising a first coil disposed about a magnetic core, and a high voltage circuit for carrying a second current (IH) to the output terminals, the high voltage circuit comprising a second coil disposed about the magnetic core, and a control relay configured to electrically connect one of the high voltage circuit and the low voltage circuit to the output terminals based at least partly on the first current (IL).