Abstract: All integrated circuits (ICs) require a power supply having a potential difference for use in powering internal integrated circuit components to ensure their operation. In some cases it is possible to inadvertently reverse the bias of the applied potential difference, resulting in damage to the IC. For propagating large currents big pass transistors are used within the circuit. Reverse bias protection for these ICs is achieved by utilizing either a protection transistor in parallel with the big pass transistor, or a diode within the big pass transistor for protecting both analog and digital ICs.

Abstract: The error compensating system and method is used in electric power monitoring systems, e.g. protective relays, and includes a test unit for applying a test signal to the front end of a data acquisition section of the power monitoring system and a phase reference module which converts the test signal to a square wave having falling and rising edges corresponding to transitions between the positive and negative portions of the test signal. A programmable logic device determines the zero crossings of the sampled digital signal from the data acquisition system and then determines the time difference between a falling edge of the module output signal and the zero crossing of the sampled digital signal. The time difference is representative of the phase shift produced by the data acquisition components. A compensation circuit adjusts the digitally sampled signals with the amount of the determined phase shift.

Abstract: A protection circuit for use in a power electronic circuit has a positive supply input, a negative supply input, and a snubber. The protection circuit includes a snubber bias lead, a positive voltage lead, a positive supply lead, a switch and a reverse polarity shut off circuit. The snubber bias lead is adapted to be coupled to obtain a bias voltage from the snubber of the power electronic circuit, the positive voltage lead is adapted to be coupled to a positive voltage lead of a power supply, and the positive supply lead is adapted to be coupled to the positive supply input of the power electronic circuit. The switch has a control input coupled to the snubber bias lead, a first terminal coupled to the positive voltage lead, and a second terminal coupled to the positive supply lead. The switch is operable to selectively allow current flow from the second terminal to the first terminal based at least in part on the bias voltage at said control input.

Abstract: A circuit to control the supply of a reactive load, for supplying variable quantities of energy to the load in a predetermined manner is included in a system. The system also includes reactive components which are connected to the load by way of a controllable electronic switch and which form a resonant circuit with the load when the electronic switch is closed. Further, the system includes a circuit for activating the electronic switch, and a control unit which coordinates the operation of the controlled supply circuit and of the activation circuit in accordance with a predetermined program. The system enables the load to be driven with a particularly low power dissipated.

Abstract: A power polarity reversal protecting circuit for an integrated circuit includes a protecting transistor, PMOS components and NMOS components, wherein the protecting transistor is a protecting PMOS transistor or a protecting NMOS transistor. If the protecting transistor is the PMOS transistor, a gate and a source of the protecting PMOS transistor are respectively connected to ground and power. A drain and a substrate of the protecting PMOS transistor is connected to a substrate of the PMOS component. If the protecting transistor is the protecting NMOS transistor, a gate and a source of the protecting NMOS transistor are respectively connected to power and ground. A drain and a substrate of the protecting NMOS transistor is connected to a substrate of the NMOS component. When the power polarity is in reversal connection, the protecting transistors are terminated to prevent damage from the power polarity reversal connection.

Abstract: An anti-reverse connection circuit for a power supply comprises an input terminal connected to a positive polarity of an external power supply, an input terminal connected to a negative polarity of the external power supply, load terminals connected to a load, a relay having a normally opened contact and an excitation coil, and a control circuit for allowing a current to flow in the excitation coil. Either one of the input terminal and the load terminal, and the input terminal and the load terminal is connected to each other via the normally opened contact, and the other thereof is directly connected to each other. Only when the positive polarity is connected to the input terminal and the negative polarity is connected to the input terminal, a switch transistor of the control circuit is turned on to allow a current to flow in the excitation coil, thereby closing the normally opened contact.

Abstract: An input protection circuit is provided for protecting internal circuitry of a handheld electric device. The internal circuitry has a positive input node and a ground node. The input protection circuit includes a power socket having a positive input node and a ground node, a bipolar junction transistor (BJT), a metal-oxide semiconductor (MOS) transistor for controlling the on and off states of the BJT, and an overvoltage protective circuit. An emitter of the BJT is electrically connected to the positive input node of the power socket, and a collector is electrically connected to the positive input node of the internal circuitry.

Abstract: The present invention relates to a multipolar electromagnetic switching module designed to be connected by line connections (t1, t2, t3) to a main electromagnetic switching device (AP) and by load connections (U, V, W, u, v, w) to at least one motor and having, in a unit (Bo), between said connections, several load paths fitted with switching poles whose contacts are always alternately closed and controlled by a switching electromagnet (EI) driven by a control circuit, each of the switching poles (C1, C2, C3) consisting of a movable contact holder (Pc) between two conductors (Cf1, Cf2) bearing fixed contacts characterized in that, for each pole, the movable contact holder (Pc) comprises two parallel loop-shaped conductors (Cm1, Cm2) connected to a connection (T1, T2, T3) and that the two fixed contact parts (Cf1, Cf2) are loop-shaped and connected to connections (U, V, W).

Abstract: A pulse signal transmitting circuit generates a pulse signal having an enhanced high-frequency component with a reduced power loss. A pulse signal is transmitted to a load circuit through a transmission cable connected to a secondary winding of a transformer. First and second transistors are connected to a primary winding of the transformer. A voltage output from an external power source is input to the primary winding of the transformer when at least one of the first and second transistors is conductive so that a pulse voltage signal is input to the transformer. A booster power supply circuit is located between the external power source and a middle point of the primary winding of the transformer. The booster power supply circuit superimposes a boost voltage onto the voltage input to the primary winding of the transformer so that a high-frequency component of the pulse voltage signal input to the primary winding of the transformer is enhanced.

Abstract: A polarity reversal protective circuit for an electronic power output stage that can be driven via a drive circuit is described. In the case of an incorrect polarization of a supply voltage, power FETs are used in at least one supply terminal to interrupt a connection of the wrongly applied supply voltage to the drive circuit and the power output stage. A definite polarity reversal protection is obtained using a circuit that is improved with respect to cost and space requirement. A single N-channel power FET is looped, with its source-drain path, into the positive supply terminal of the supply voltage. The source terminal of the N-channel power FET is connected with the positive supply terminal. The gate terminal of the N-channel power FET is connected to a collector of a PNP transistor, which is additionally connected to an output of the drive circuit via a current-limiting resistor.

Abstract: Circuitry is provided in a device to automatically change the relative position of the electrical lines which enter the device upon detection of a miswired condition. More specifically, the circuitry allows the device to function normally even if an installer accidentally inverts (i.e., flips or reverses) the wiring connections when attaching connectors to a communication/power line of the device. In this manner, the installer does not need to rewire the lines.

Abstract: A safety circuit system for a DC driven device for use with a fluid delivery system includes a first voltage potential DC power line, a second voltage potential DC power line, a controller and a safety circuit. The first voltage potential DC power line is coupled to provide a first voltage potential to the DC driven device, and the second voltage potential DC power line is coupled to provide a second voltage potential to the DC driven device such that the second voltage potential is different relative to the first potential. The controller controls at least the first voltage potential on the first voltage potential DC power line. The safety circuit has an enable state and a disable state, in which the default state is the disable state. The safety circuit is coupled to the controller, and the controller controls the safety circuit to place the safety circuit in the enable state independently of controlling the first voltage potential on the first voltage potential DC power line.

Abstract: A control arrangement and method is provided for a power electronic system configured as a high-speed source-transfer switching systems (HSSTSS). The HSSTSS supplies an electrical load with alternating current from either a first source or a second source via respective first and second solid-state switches. The HSSTSS also includes a controller that samples the voltage waveforms of each of the first and second sources to detect when transfer between the sources is desirable, e.g. outages or voltage that is either too low or too high. The controller provides appropriate control signals to control operation of the solid-state switches and transfer supply of the load therebetween. The control arrangement avoids undesirable current flow between sources via a comparison of the voltages of the sources and current in the outgoing source, i.e.

Abstract: The polarity reversal protection circuit provides for a semiconductor switch (11) to be connected in parallel with the polarity reversal protection diode (10), which switch is switched off in the event of polarity reversal and is switched on during normal operation.

Abstract: The present invention relates to a multipolar electromagnetic switching module that is connected by line connections (t1, t2, t3) to a main multipolar electromagnetic switching device (AP) and by load connections (U, V, We U′, V′, W′) to at least one motor and having between said connections several power current lines (C1, C2, C3) fitted with switching poles the contacts of which are always alternately closed, and controlled by a switching electromagnet (E2) driven by an electric control circuit (CC), and characterized in that the switching poles (C1, C2, C3) and current lines are arranged to perform a motor control function such as reverser, star-triangle or distributor and in that the pole control assembly consisting of the switching electromagnet (E2) and the control circuit (Cc) is offset relative to the switching poles and load paths in a direction perpendicular to the rear fastening surface (P) of the module such that the width (L) of the module is reduced and more or less identical t

Abstract: A circuit to control the supply of a reactive load, for supplying variable quantities of energy to the load in a predetermined manner is included in a system. The system also includes reactive components which are connected to the load by way of a controllable electronic switch and which form a resonant circuit with the load when the electronic switch is closed. Further, the system includes a circuit for activating the electronic switch, and a control unit which coordinates the operation of the controlled supply circuit and of the activation circuit in accordance with a predetermined program. The system enables the load to be driven with a particularly low power dissipated.

Abstract: Circuitry is provided in a device to automatically change the relative position of the electrical lines which enter the device upon detection of a miswired condition. More specifically, the circuitry allows the device to function normally even if an installer accidentally inverts (i.e., flips or reverses) the wiring connections when attaching connectors to a communication/power line of the device. In this manner, the installer does not need to rewire the lines.

Abstract: A car battery jumper cable for coupling an effective or charged power source to a battery (failed or not charged) accurately, which includes a relay switching circuit connected to the power source and the battery by two current conductor pairs, first and second voltage polarity recognition circuit respectively connected to the power source and the battery by a respective voltage conductor pair to recognize the polarity of the power source and the battery, a logic recognition circuit, which produces a control signal subject to the polarity of the power source and the battery, and a driving circuit controlled by the control signal from the logic recognition circuit to drive the relay switching circuit, enabling the two poles of the power source to be accurately coupled to the two poles of the battery.

Abstract: The provision of an isolation gate connecting unassociated active areas of adjacent transistors formed in a semiconductor substrate provides effective isolation of the adjacent transistors with no additional process steps required. The isolation gate is tied to a reference to ensure that a channel between the unassociated active areas is not formed, and effective isolation is provided. The adjacent transistors are cross coupled to form sense amplifiers for dynamic random access memory devices.

Abstract: The invention relates to a circuit for protecting consumers from damage caused by polarity reversal in an electrical system, comprising a limiter and a tripping device, wherein the system voltage supply is limited when polarity is reversed and the voltage source connected with reversed polarity can be disconnected.

Abstract: A power supply circuit for conducting current from an ac voltage source to an associated electrical load having a power supply circuit for feeding current to the load in alternate half cycles. The circuit comprises in combination with an ac voltage source and first circuit for conducting current in one direction through the load in a first half cycle and second circuit for conducting current through the load in the opposing direction in a second half cycle, the first and second circuit being responsive to the positive and negative cycling of the ac voltage source; a first switching control responsive to the positive half of the sinusoidal voltage waveform from the ac voltage source for energizing the first circuit and a second switching control responsive to the negative half of the sinusoidal voltage waveform from the ac voltage source for energizing the second circuit.

Abstract: An apparatus that can be used to jump-start a car that has a weak battery. It includes a battery booster pack or a battery booster cable that is polarity sensitive and can detect proper and improper connections before providing path for electric current. This apparatus eliminates the danger of reverse connections, shorts, fires, spark firing and battery explosion. The apparatus requires no separate switching mechanism to turn power on or power off. It also does not require the imperfect human judgment of any indication device to determine correct or incorrect connection. The clamps detect for the correct polarity and automatically control the power. Power turns on once a good connection has been made. If user makes a wrong connection, there will be no power but its warning signal will go off. Once a clamp is dislodged from the battery terminal, it automatically turns power off without the need to deactivate a switch.

Abstract: A circuit to control the supply of a reactive load, for supplying variable quantities of energy to the load in a predetermined manner is included in a system. The system also includes reactive components which are connected to the load by way of a controllable electronic switch and which form a resonant circuit with the load when the electronic switch is closed. Further, the system includes a circuit for activating the electronic switch, and a control unit which coordinates the operation of the controlled supply circuit and of the activation circuit in accordance with a predetermined program. The system enables the load to be driven with a particularly low power dissipated.

Abstract: A distributed airbag firing system (10) includes a controller (12) receiving sensor signals from a sensor (20) over a two-wire bus (18). The controller provides a firing command over to the two-wire bus to a squib driver circuit (26), which provides the firing current necessary to detonate a squib device (32) and inflate the airbag. The squib driver circuit includes a rectifier (42) with its first and second inputs interchangeably connected to the two-wire bus. The rectifier circuit converts the voltage orientation on the first and second conductors to a positive potential on a first output conductor and a negative or ground potential on a second output conductor. The interchangeability of the first and second inputs of the rectifier to the two-wire bus makes the connection arbitrary and fail-safe.

Abstract: An electronic disconnect circuit protects an electronic device, such as a radio, installed in a motor vehicle from overvoltage condition in which the normal internal protection is inadequate. A normally closed relay includes 2 sets of terminals connected in the ground conductor and in the voltage conductor of the power cable connected to the electronic device. The relay coil is connected through a diode which becomes conductive if the voltage in the ground conductor rises above the voltage in the other conductor, thus protecting the radio or similar electronic device from a reversal of polarity as would occur when a battery charger or similar device is improperly connected to the vehicle. A switching transistor responds to an over voltage condition to turn on the relay coil when an over voltage condition occurs, such as during a high voltage jump start or a high voltage transient condition.

Abstract: Provided is a protection circuit for high speed signal communication via a two-wire connection between the two output terminals of a PECL driver and the two input terminals of a PECL receiver. The PECL driver and receiver are supplied with power from individual power supplies. The protection circuit includes two diodes connected in series with a respective wire with their cathodes electrically coupled to the respective output terminal of the PECL driver and their anodes electrically coupled to the respective input terminal of the PECL receiver, and two resistors connected between the PECL receiver power supply and the anodes of the respective diode. The resistance of the resistors ensures forward biasing of the diodes when the receiver power supply is supplying power. A capacitor may be connected in parallel with the respective diodes.

Abstract: A circuit for controlling a fail-safe operation of measurement and control apparatus for detecting the presence or absence of water by making a measurement of the impedance experienced in a gap between an insulated tip of the electrode and a surface held at a reference voltage or else connected to ground. The apparatus may be configured to provide an alarm when water is present and should not be, or vice versa. The circuit comprises comparators IC1 and IC2, a phase detector IC3 and a triple-redundant drive circuit 12 which drives a relay 14. The function of IC1 is to ensure that when operating with water as the normal condition, an electrode fault, such as could be caused by excessive contamination, will cause the system output to indicate an abnormal condition. The main function of IC2 is to discriminate between the water condition and the steam condition. The function of IC3 is to ensure that there is no output if there exists an abnormal condition or any fault condition.

Abstract: A power filter circuit for protecting electronic equipment from electromagnetic interference introduced by a supply system circuit includes a fault condition sensing circuit capable of detecting whether the supply system circuit is properly wired. The sensing circuit controls switching circuits in accordance with the determination of whether the supply system is properly wired. The sensing circuit activates a first switching circuit to form a short circuit between the neutral and ground conductors of the power filter circuit when it is determined that the supply system circuit is properly wired. If any wiring fault conditions, including a reverse polarity wiring, is detected by the sensing circuit, the first switch is not activated and the short circuit is not formed between the neutral and ground conductors.

Abstract: A semiconductor switch, particularly an MOS high-side power switch, having at least one power transistor for driving a load, and having a circuit for driving the power transistor via an external control signal by activating the power transistor over its gate. In order to also assure low dissipated power of the MOS power transistor given a reversal of the power supply, an auxiliary circuit is provided for the activation of the MOS power transistor via its gate given upon such reversal.

Abstract: A plurality of air conditioning system control units are connected to each other through a communication line (20). Discharge resistors (R1, R2) are provided for discharging residual charges of the communication line (20). The control unit has a power superposition circuit (50) for applying a direct-current voltage and outputs an identification number signal from the power superposition circuit (50) to the communication line (20). The control unit further has a polarity select circuit (60) having a negative-polarity resistance characteristic that current increasingly flows as an applied voltage is lowered, and a voltage discriminating circuit (70) for detecting the terminal voltage of the polarity select circuit (60). When detecting the voltage of the communication line (20), the control unit determines whether its own control unit is a master unit or a slave unit according to output signals from the voltage discriminating circuit (70) and a polarity discriminating circuit (3C).

Abstract: A switching system having a plurality of positions for separating or interconnecting a generator, a network transformer, and a starter device, the system including a circuit breaker for the generator and a busbar disconnector for separating or interconnecting the generator and the network transformer, and a starter disconnector for separating or interconnecting the generator and the starter device. The busbar disconnector includes a first fixed contact and a first moving contact that co-operates by sliding with the first fixed contact, the first fixed contact and the first moving contact being integrated with the circuit breaker of the generator. The starter disconnector includes a second fixed contact and a second moving contact that co-operates with the second fixed contact by rotation. This organization remains economical to implement even for applications in which the generator is an alternator in a combined cycle or a gas turbine power station.

Abstract: A power management system for an implantable device is disclosed. One application is an implantable cardioverter/defibrillator. Charging circuits for implantable cardioverter/defibrillators require relatively large currents from the power supply. The present power management system provides extended device operation and reduced charge cycle time. The present system monitors both current and voltage drawn from the power supply to prevent a loss of system voltage. Elective replacement indication is performed using charging information provided by the present power management system.

Abstract: A method and arrangement for controlling the output of electrical consumers connected to ac line voltage, especially of electric motors and the like, in which the output is changed by changing the phase control of the electric alternating magnitude supplied to the consumer. The extent of the firing angle determining the extent of the phase control is varied toward larger or smaller values around the given reference value of the firing angle, which reference value corresponds to the desired power consumption, so that asymmetry of the firing angle is produced with respect to time between two successive full waves, whereby odd-numbered harmonics are sharply reduced as even-numbered harmonics slowly increase.

Abstract: A method for controlling the output of electrical consumers connected to ac voltage, especially ohmic loads such as hot-plates, fans, hot-air blowers, electric heaters and the like, wherein an electric or electronic circuit component which conducts ac voltage in both directions, preferably a triac, is connected in series with the consumer, and the output control is effected at the consumer by the given angle of the phase control. An additional electric or electronic circuit component is arranged in parallel to the first series switching element, however, the additional component is controlled first so as to conduct in a controlled manner at the trigger time determined by the device control. The current flow of the additional component is substantially taken over by the first circuit component at the latest when reaching a predetermined threshold current through the load or a threshold voltage at the load or triac.

Abstract: A motor starter circuit providing recovery of the energy trapped in the motor windings when the supply voltage and current have opposite polarities by selectively controlling actuation of a plurality of high speed switches. The circuit, for use with a multiphase motor and power source that provides positive and negative voltage alternations which result in the generation of a load current in the motor having positive and negative alternations, includes a plurality of switch-diode combinations electrically configured such that for a given pair of supply voltage/load current polarities, only one diode of each combination may be forward biased.

Abstract: A method of powering a train powerline with a second source including using a local power controller in the trainline to determine the polarity of the power lines which run through the trainline. The local power controller then connects the second power source to the power lines with the determined polarity. Finally, the local power controller powers the power lines with a second power source once the connection of the appropriate polarity has been made.

Abstract: A lift pin 95 for dechucking a substrate 15 held to a chuck 50 by residual electrostatic charge, the substrate being processed in a plasma formed using RF currents, is described. The lift pin 95 comprises (a) a movable elongated member 110 having a tip 115 suitable for lifting and lowering the substrate 15 off the chuck 50, and capable of forming an electrically conductive path between the substrate 15 and a current sink 105. The electrically conductive path comprises at least one of the following: (1) a frequency selective filter capable of filtering RF currents flowing therethrough so that substantially no RF currents flow through the filter; or (2) a resistor having a resistance sufficiently elevated to reduce the voltage caused by RF currents flowing therethrough, by at least about 50%.

Abstract: Current flow between a battery (14) and electrical ground (18) and through a load (16) is controlled by an apparatus (10). Preferably, the load (16) is a seat heat element. A current direction sensitive MOSFET (34) acts as a switch to control the current flow. The MOSFET (34) has a source (40) connected to the load (16), a drain (42) intended for connection to a positive terminal (26) of the battery (14), and a gate (46) for receiving a control voltage. Transistors (56, 66) control the voltage at the gate (46) of the MOSFET (34). The apparatus (10) is self-protecting against damage upon reverse polarity connection of the battery (14). A switch-protecting resistor (36) is intended for connection to electrical ground (18). The switch-protecting resistor (36) provides a path for electrical energy from the battery (14) to the gate (46) of the MOSFET (34) when the battery (14) is reverse polarity connected.

Abstract: A power source miswiring detection apparatus for detecting a miswiring of wires of a power source, including a pulse generator for generating a first pulse having a pulse width corresponding to a first phase difference between a first pair of two phases of a three-phase alternating power source, and a second pulse having a pulse width corresponding to a second phase difference between a second pair of two phases of the three-phase alternating power source which is different from the first pair of two phases, and a microcomputer for detecting a third phase difference between the first pulse and the second pulse to judge whether the third phase difference is in a predetermined range, and detecting the miswiring if the third phase difference is judged to be out of the predetermined range.

Abstract: A fail-safe circuit (10) comprises a storage battery (11) for electrical charges as well as a first charge path (12) which optionally connects the storage battery (11) to a first potential (UL). A second charge path (14) and a third charge path (15) optionally connect the storage battery (11) with a second or third potential (UE1, UE2). The first and second switching devices (16, 17), which operate as function of the first and second switching events (TA, TB), each comprise a first and second switching contact (A1, B1) in the first charge path (12) and a second switching contact (A2, B2) in the second and third charge path (14, 15). The actuation coils (LC, LD) of the third and fourth switching devices (18, 19) are in the second and third charge path (14, 15) and each have a first switching contact (C1, D1) in the first charging path (12) and a second contact (C2, C2', D2, D2').

Abstract: A device for controlling a switching relay to deliver power to a load. The switching relay selectively couples a hot leg of a utility power supply to the load. The load is coupled to a neutral wire of the utility power supply. The device includes a sensor for detecting whether an area is occupied. If the sensor indicates that the area is occupied and the load is powered off, the device monitors the line voltage for a zero crossing. Upon detecting a zero crossing, an amount of time to a subsequent zero crossing is measured and stored. Then, the device waits the amount of time between zero crossings, less a delay time for closing the contacts of the relay, and initiates a closing of the contacts of the relay. Similarly, when the sensor detects that the area has not been occupied for a predetermined amount of time and the load is powered on, the line voltage is monitored for a zero crossing and a time to a subsequent zero crossing is measured and stored.

Abstract: A synchronization control scheme that provides a drive signal to a plurality of switching circuits and method of operation therefor.

Abstract: For appropriately polarity recognition and corresponding switchover of a output stage of a proximity switch or the like connected to a supply voltage (VB), even while continuously activated, when a change in load polarity occurs, the proximity switch having in each case a high side driver and a low side driver, it is proposed to define on the output-side voltage axis between the positive supply voltage (+VB) and the negative pole or ground an upper and a lower detection window which sense the load configuration, each at a distance from the working points (which remain in a steady state) of each output stage driver, such that when a change in load configuration occurs, the potential of the output connection, to which the load configuration detection stage is connected, passes only briefly through these detection windows, and such that the transient signal changes which result therefrom in each window region are used for appropriately polarized switchover to the respective correct output stage circuit section b

Abstract: A polarity reversing circuit having energy compensation may comprise a first inductor connected between the first electrode and a negative terminal of a power supply. The positive terminal of the power supply is connected to the second electrode. A diode and a first capacitor are connected in series across the first inductor so that the cathode of the diode is connected to the first electrode. A second capacitor and a switching device are also connected in series across the first and second electrodes. A second inductor is connected between the switching device and the anode of the diode. A bi-directional converter is connected between the power supply and the second capacitor. The voltage polarity between the first and second electrodes may be reversed by actuating the switching device to switch between a non-conducting state and a conducting state.

Abstract: A power supply circuit prevents, without the use of a series diode, the flow of reverse current from a battery to an AC power adaptor when the power adaptor is disconnected from its external power source. The circuit includes both voltage and current detectors to determine if the output voltage and current of the power adaptor are above or below predetermined reference levels. A summing circuit sums the outputs of the voltage and current detectors, and when both the detected voltage and current are below the reference levels, a switch disconnects the battery from the output terminal of the power adaptor, thereby preventing reverse current flow.

Abstract: A control arrangement and method is provided for high-speed source-transfer switching systems (HSSTSS). The HSSTSS supplies an electrical load with alternating current from either a first source or a second source via respective first and second solid-state switches. The HSSTSS also includes a controller that samples the voltage waveforms of each of the first and second sources to detect when transfer between the sources is desirable, e.g. outages or voltage that is either too low or too high. The controller provides appropriate control signals to control operation of the solid-state switches and transfer supply of the load therebetween. The control arrangement avoids undesirable current flow between sources via a comparison of the voltages of the sources and current in the outgoing source, i.e. a polarity comparison to ensure that the current that will flow in the incoming source after transfer will be in opposition to the current flowing in the outgoing source before transfer.

Abstract: When a trouble occurs in a cable, a feeding pass for another cable is ensured. In a feeding pass switching circuit, optical fibers are respectively connected to the terminals A, B and C. When a negative current is applied to the system in a state where a BRANCH2 is put in an open circuit and a TRUNK is grounded, a relay K1 is activated, and then a relay K2 is activated. Successively, when a positive current is supplied from the TRUNK, a cable connected to the TRUNK and a BRANCH1 is fed from both terminals. When the positive current is supplied from the BRANCH1 in a state where the TRUNK is put in a open circuit and the BRANCH2 is grounded, a relay K3 is activated. Successively, when the negative current is supplied to the BRANCH2, a relay K5 is activated. In such a manner, the power is fed to each feeding pass from one terminal.

Abstract: A method of and apparatus for actuating an automatic transfer switch for disconnecting a motor load from a normal source of voltage and reconnecting the load to an alternate source of voltage at a time when phase differences between the output voltage of the disconnected motor load and of the alternate source voltage are minimized to prevent excessive in-rush currents to the motor upon reconnection. Actuation of the transfer switch is commenced when the difference in phase between the normal source and alternate source is equal to a predetermined number of degrees depending upon whether the alternate source frequency is greater or less than the normal source frequency.

Abstract: A switch having controlled rise and fall characteristics for electronic switching and power controlling a load has a switching element for the load controlled by a rectifier bridge, a filter circuit, a feedback amplifier stage, a low-power switch (SCR) and a diac. The feedback amplifier stage has a phase shifting circuit, a switching and/or amplifying circuit and a filter stage. The filter stage has a capacitor, Zener diode, a switch and, possibly, a potentiometer for controlling rise-control and fall-control resistors.

Abstract: An electrical power protection integrated circuit provides protection against reverse battery and overvoltage conditions that is particularly of value in automotive applications in which reverse battery and overvoltage conditions are commonplace. The electrical power protection integrated circuit device contains a reverse battery condition protection element, supplied either directly or indirectly from a battery power source, that protects against a reverse battery condition of the battery power source and an overvoltage protection element coupled to the reverse battery condition protection device that protects against an overvoltage condition of the battery power source and produces a protected power output that is isolated from both battery overvoltage and reverse battery voltage conditions. Additionally, the integrated circuit device can further produce an auxiliary protected power output that is isolated from reverse battery voltage conditions.