摘要:
Current limiters, preferably PTC resistors, are used for limiting short-circuit current when connected in series to capacitors and converter valves. Protective devices operating with these PTC resistors are able to work reversibly and respond without arcing. They have a low inductance and can be used in space-saving designs. Protective circuits with such PTC resistors have a low loss, are shake-proof, and can be integrated into an existing cooling circuit. They respond autonomously and enable a flexible application. The PTC resistors preferably are constructed in a meander shape of porous metal foam or a metal braid or fabric and have electrical contact bridges between their resistor tracks. At least 2 resistor tracks that are electrically connected in parallel are arranged at a small distance on top of each other in such a way that partial currents (I1, I2) flow in opposite directions through resistor branches in superposed track areas formed in this manner. The resistor tracks can also be arranged in grooves of a cooling body or may have a circular shape. A compensation resistor for compensating uncompensated marginal areas of these resistor tracks can be provided in serial connection to meander-shaped, parallel connected resistor tracks.
摘要:
A high pulse rate pulse power source for supplying controlled high energy electrical pulses at rates of 2000 Hz or greater. The source includes a pulse generating circuit including a charging capacitor, a solid state switch and a current limiting inductor. Pulses generated in the pulse generating circuit are compressed in at least two pulse compression circuits and a step-up pulse transformer increases peak voltage to at least 12,000 volts. A very fast regulated resonant power supply is provided for charging the charging capacitor in less than 400 microseconds and a pulse control system including a programmed processor controls the charging of the charging capacitor to an accuracy of less than about one percent at a rate of at least 2000 charges per second.
摘要:
A method of generating a protection-triggering signal using a triggering device of a selective-protective arrangement for an electrical power network to be monitored. In order to produce a protection-triggering signal in a relatively short time after the occurrence of a fault in the power network, a triggering device is provided in which a neural network is associated with each phase conductor in the power network. Successively sampled normalized values of the current in the power network are applied at the same time to the various neurons in the input layer of each neural network and a subsequently sampled normalized value (comparison value) of the current compared with the signal from the output neuron. If the normalized comparison value exceeds the output from the output neuron, a protection-triggering signal is generated.
摘要:
A miniature motor having a positive temperature coefficient thermistor comprising a stator having a permanent magnet serving as a field, a rotor formed by winding a plurality of rotor windings on a rotor core, brushes supported by a motor cover plate for feeding current to the rotor windings by making contact with a commutator, positive temperature coefficient thermistor for controlling current to the rotor windings, in which the positive temperature coefficient thermistor has one pole on one pole surface thereof, and a plurality of independent split poles corresponding to the rotor windings on the other pole surface thereof, and is fitted to an end face of the rotor core;the rotor windings being connected to the split poles of the positive-coefficient thermistor in such a manner as to be connected in series with the split poles of the positive-coefficient thermistor.
摘要:
A vehicle includes an engine, a controller for turning off the engine when the vehicle is idle, a motor/generator for starting the engine, an inverter for converting a DC auxiliary voltage from a battery into an AC voltage for powering the motor/generator, and a device for isolating a DC voltage from the DC auxiliary voltage to prevent voltage sag in a vehicle system during engine starting. The device includes a transformer, a rectifier/regulator, and an isolator. A mechanical relay opens, or an FET is activated, to isolate the DC voltage during engine start. A method for preventing voltage sag in an auxiliary vehicle system includes detecting a commanded engine start, comparing a measured auxiliary voltage to a threshold, isolating a predetermined DC voltage from a DC auxiliary voltage when the measured auxiliary voltage is less than the threshold, and powering the auxiliary vehicle system using the isolated DC voltage.
摘要:
A high voltage/high current electric pulse generator. Spark gap switches (E1, E2, E3) having a trigger electrode are connected to a trigger control circuit (CD). Switch (E1) is connected between the outer conductor of cable (C2) and an inner conductor of cable (C1). Switch (E2) is connected between the outer conductor of cable (C3) and the inner conductor of cable (C2). Switch (E3) is connected between output terminal (S) and the internal conductor of coaxial cable (C3). The outer conductor of cable (C1) is connected to ground and voltage source (SHT) is connected to internal conductors of the cables. The source charges cables (C1, C2, C3) in parallel when switches (E1, E2, E3) are off. A first ballast resistor (r) is connected between the first electrode and the trigger electrode. Load resistor (R6) is connected between the output terminal(S) and the external conductor of cable (C3). Resistor (R5) is connected between the outer conductor of cable (C 3) and the outer conductor of cable (C2). Resistor (R4) is connected between the outer conductor of cable (C2) and ground. Resistor (R3) is connected between the inner conductor of cable (C3) and the inner conductor of cable (C2). Resistor (R2) is connected between the inner conductor of cable (C2) and the inner conductor of cable (C1). Resistor (R1) is connected between the inner conductor of cable (C1) and voltage source (SHT). Load resistors (R2, R3) are connected between the internal conductors of the coaxial cables.
摘要:
A high power fast switch for generating pulses of current to a load from a high voltage power source. A laser beam illuminates a cathode which simulates the emission of pulses of electrons which illuminate a diamond target. The pulses of electrons cause the diamond target to become conductive permitting high power pulses of electric current to pass through the diamond target from a high voltage source to a load. In a preferred embodiment a Klystron buncher compresses the electron pulses onto the diamond target.
摘要:
A pulsed current source in which the dc component of the pulsed current is independent of variations in the duty cycle of the current pulses. A dc current source supplies a current I through a switch that alternately switches the current between a first output and a second output to produce at the first output the pulsed current I.sub.p. The dc component of the current at the second output is added to the current I, thereby making the dc component of the pulsed current insensitive to the duty cycle. In systems in which additional processing produces from I.sub.p a set of currents, the dc component of the sum of a first subset of these currents is made to equal I by adding to the input of the switch the dc component of the sum of those currents in the complement of the first subset.
摘要:
A generator for producing high-voltage rectangular pulses is provided which comprises devices for conversion of input power supplied from a DC source into pulses of output power using capacitive storage units, a pulser head for the connection of a coaxial cable leading to a load and a gas-filled pulser tube.