Abstract: An amperage control for an electrically operated valve having a coil. A process control apparatus generates a plurality of electrical operating data signals, each signal corresponding to an operating parameter of the valve. A valve control apparatus transmits voltage to the coil of the valve to control the operation of the valve, the valve control apparatus receiving at least one operating data signal generated by the process control apparatus. A current flow is created in the coil of the valve upon receiving voltage from the valve control apparatus. A current senses the flow of current in the electrically controlled valve, and creates an electrical signal responsive to the current flow in the coil of the valve. When the signal created by the current sensing apparatus is applied to the valve control apparatus, the valve control apparatus modifies the operation of the valve responsive to the signal created by the current sensing apparatus.

Abstract: A speed control and stall protection system 10 for an electric DC brush motor includes a DC brush motor M. At least one relay K3 is connected between the motor and a power supply. A speed sensing circuit 20 is constructed and arranged to generate a signal indicative of a speed of the motor. A motor control and protection circuit 116 is constructed and arranged to receive 1) the signal from the speed sensing circuit and 2) a control signal input for operating the at least one relay to control operation of the motor. When a stall condition is determined based on the signal from the speed sensing circuit, the motor control and protection circuit is constructed and arranged to control the at least one relay to disconnect power to the motor.

Abstract: The invention concerns a method for deicing energized electrical transmission lines by means of an apparatus capable of producing an angular offset between its terminals. The method consists in: selecting segments (4, 6) of electrical transmission lines to de deiced, connecting the segments (4, 6) so as to form a loop, connecting the apparatus in series with the segments (4, 6) of the loop to be deiced. In the case of an apparatus with adjustable angular offset, it consists in switching on the apparatus and adjusting the angular offset to impose an increase of current flowing in at least one of the segments (4, 6) as the case may be. In the case of a apparatus with fixed angular offset, it consists in using a switch (54) or a circuit breaker (28) so as to connect the apparatus in the loop, the apparatus and the line segments being previously selected such that the angular offset imposes the required current increase to the deicing of at least one of the segments (4, 6) of the loop.

Abstract: A balancing circuit for voltages of a series connection of capacitors, particularly for intermediate circuit capacitors (3) of an inverter, there being at least two intermediate circuit capacitors connected in series over intermediate circuit voltage. The balancing circuit comprises capacitor-specific freely oscillating inverters (4), the input poles of which are connected in parallel with the capacitor corresponding to the inverter and the output poles of which are connected in parallel to provide a voltage source (Va).

Abstract: The protective circuit for analog sensors has transistors respectively located in a power supply voltage line and in a ground line. The control electrode of said circuit is located between the supply voltage and the ground via a voltage divider. The sensor output line is connected to the ground potential of the control device via a pull-down resistor. During normal operation, both transistors are connected. Both transistors switch off when the ground line is disconnected. This prevents a current from flowing to the sensor output line via the power supply voltage line, the voltage divider or via the sensor. The sensor output line is, in fact, pulled to the ground potential by the pull-down resistor. This prevents the appearance of a defective signal that could emulate a wanted signal.

Abstract: A microelectromechanical system (MEMS) device is used to transfer power from a source generator to a power generator that delivers electrical power to a load, while maintaining electrical isolation between the source generator and power generator for size critical applications where transformers or coupling capacitors would not be practical, but where electrical isolation is desired.

Abstract: An analog or digital circuit that senses both low and high input voltage and operates to disconnect both line and neutral electrical power connections to a protected device when abnormally low or high voltages are received from a single- or multi-phase power source, and reconnects the protected device when input power has stabilized. The sensing circuit and power supply is functional with voltages up to at least 240 Vac. The nominal 120 Vac circuit is designed to withstand a 6 kilovolt surge without damage. The apparatus does not disconnect the ground line during an out-of-tolerance voltage condition.

Abstract: An actuator driving apparatus comprises the following. A start signal generator generates a start signal having a frequency substantially equal to the resonance frequency of the movable portion of an actuator. A rock detector detects rock of the movable portion. A drive timing signal generator generates a drive timing signal based on the output of the rock detector. A switch is connected to the start signal generator and drive timing signal generator for selectively transmitting their outputs to a section arranged in a subsequent stage. A drive signal generator generates a drive signal based on the output of the switch, and supplies it to the actuator. A superposition preventing section prevents a frequency component of a frequency substantially equal to the resonance frequency from being superposed upon the output of the rock detector. The apparatus performs driving according to the rocking state of the movable portion, by switching the switch.

Abstract: An uninterruptible power supply (UPS) system includes an AC power input configured to receive AC power from a single-phase AC power source or a multi-phase AC power source, a DC power source, an output circuit including a power output, a controllable switch configured to selectively couple at least one of the AC power input and the DC power source to the output circuit, and a processor coupled and configured to affect operation of the output circuit depending upon which of single-phase and multi-phase operation of the UPS is indicated.

Abstract: An Electrical Static Discharge (ESD) system comprises a user-accessible subsystem (for example, a first gasoline pump), a local ground, a resistor-fuse element, and a main ground. The local ground dissipates a static electric charge from the user-accessible subsystem. The resistor-fuse element conducts the static electric charge from the local ground, and limits a reverse electric current to the local ground. A main ground receives and dissipates the static electric charge from the resistor-fuse element.

Abstract: A method and apparatus for aggregating power from multiple sources generates a single direct current regulated voltage. The apparatus comprises a plurality of slave voltage converters and a master pulse width modulator circuit. Providing a plurality of direct current power sources, current is drawn through a plurality of lines connected to the plurality of direct current power sources. An open circuit voltage for each direct current power source is unknown. Each line of the plurality of lines has a line resistance. The line resistance of at least some of the plurality of lines may be unknown. The line resistance of at least some of the plurality of lines is large. The single direct current regulated voltage is generated from the drawn current.

Abstract: A load-protection control circuit of a power supply, which applies to the power supply that has a maximum power-limiting function. The power supply includes a power transformation circuit which outputs a direct current to drive loads and a control circuit which can switch the power transformation circuit electrically coupled to a power-protection circuit that has a voltage representing reference power. The direct current voltage driving the load is compared with the voltage representing reference power by the power-protection circuit to output a protection signal to the control circuit for switching the power transformation circuit. The power-protection circuit and the control circuit are electrically connected to a switcher circuit connected to a switch, wherein the switch can switch the switcher circuit to be in open-circuit or close-circuit state in order to determine whether the protection signal is transmitted to the control circuit. Thereby, the objective of load-protection control is accomplished.

Abstract: Power switches are provided with measures for preventing a recommendation of the arc from the secondary current path to the main current path and/or measures for returning the current limiter during the recommutation of the light art. A corresponding arrangement for carrying out the method is provided with means in the power switch and/or current limiter for preventing a switch failure of the current limiter disposed in the secondary current path of the power switch. The current limiter can be especially a PTC current limiter.

Abstract: A universal interface circuit and an associated method are provided that can supply a computer logic circuit, such as the components mounted upon an adapter card, with first and second inputs having first and second predetermined voltage levels, respectively, based upon power drawn from both first and second supply voltages. The interface circuit typically includes a first power supply circuit for providing the first input having the first predetermined voltage level in response to the first supply voltage. Additionally, the interface surface includes a regulator for generating an output having the second predetermined voltage level in response to the first supply voltage. The interface circuit further includes a second power supply circuit for providing an output that also has the second predetermined voltage level, albeit in response to the second supply voltage.

Abstract: A gapped ground safety device is provided to protect workers on de-energized underground distribution cable from ground faults or accidental energization. The device comprises a combination precision gap and an MOV surge arrester.

Abstract: A locomotive auxiliary power system and control techniques for such a system are provided. In one exemplary embodiment the auxiliary power system includes an auxiliary alternator coupled to the internal combustion engine of the locomotive. The system further includes an auxiliary power bus powered by the auxiliary alternator. A rectifier may be connected between the auxiliary alternator and the auxiliary power bus. A plurality of devices may be electrically powered by the auxiliary power bus. A respective inverter is connected between the auxiliary power bus and each device, wherein the inverter provides a path for diverting electrical power generated during a transient mode by at least one the plurality of devices. In one exemplary embodiment, the auxiliary alternator is made up of a single alternator connected through a single shaft to the internal combustion engine.

Abstract: An electrostatic discharge protective circuit including an ESD protective circuit which has a trigger terminal and forms a discharge path from a first node to a second node when trigger signals are supplied to the trigger terminal, a trigger circuit included in a circuit to be protected which is connected between the first and second nodes, the trigger circuit having a first MOS device, and which functions as a part of the circuit to be protected at the time of normal operation when ESD voltage is not applied, and forms a conductive path between a drain and source of the MOS device when ESD voltage of a predetermined value or more is applied to the first node during a normal operation, and supplying the trigger signals to the trigger terminal of the ESD protective circuit when the first MOS device becomes conductive.

Abstract: The invention is a dual stage power supply with a protection circuit for preventing reverse conduction through the lower voltage driver of the dual stage power supply and excess power dissipation when the higher voltage driver is on. In one embodiment of the invention, the protection scheme comprises a comparator that detects when the voltage on the output pad exceeds a predetermined voltage and a protection transistor which is controlled by the comparator to block reverse conduction through the lower voltage driver when the higher voltage driver is operating.

Abstract: A circuit protection system is provided that provides a dynamic delay time to an upstream circuit breaker if a fault is detected in a circuit where the dynamic delay time can be based upon the location of the fault, such as the nearest downstream circuit breaker. A control processing unit can determine a dynamic delay time for opening a first circuit breaker if a fault is detected in the circuit. The control processing unit delays opening the first circuit breaker until after the dynamic delay time has elapsed to provide an opportunity for the nearest circuit breaker to clear the fault.

Abstract: A steering wheel lock apparatus having high reliability. The steering wheel lock apparatus (1) includes a lock pin (21), which engages a steering wheel (5), a motor (23), which moves the lock pin, and a control circuit (31), which controls the motor. The control circuit includes a power supply line (72b), which provides locking current to the motor for locking the steering wheel. A breaker circuit (61) selectively breaks the power supply line when a user operates an ignition switch knob (81) to start the vehicle.