Abstract:
An inverter device for supplying a stable, high power-factor input current while restraining higher harmonics to be low is provided by a simple circuit structure in which a pulsating DC voltage supplied through a power circuit is provided to a smoothing condenser, a direct current is provided from the smoothing condenser to an inverter circuit section, and an input current path is formed from the power circuit through an impedance element to a switching element of the inverter circuit section and to part of an oscillation circuit.
Abstract:
To control the speed of an alternating-current drive capacitor motor of a centrifuge, the motor is connected to the bridge arm of a single-phase inverter. The bridge arm is connected at each of its ends to the midpoints of a series circuit of two capacitors and two field-effect transistors, these series circuits being connected in parallel with one another and connected to the output of a rectifier operated by the a.c. voltage supply. During operation, the capacitors are discharged by means of triggering the field-effect transistors alternately via the capacitor motor, the triggering being performed via a microprocessor serving as a pulse generator.
Abstract:
A single power converter is capable of drawing low distortion current from an AC line and delivering DC or AC power to a load. The single power converter is used to independently control the input current and the output current. The power converter transformer has an output winding which is controlled by pulse-width modulation (PWM) and a frequency controlled boost winding for controlling input current.
Abstract:
The present invention relates to a compact electrical power supply which derives electrical energy from a low frequency medium voltage source (e.g. a 120 V 60 Hz ac main), and converts the electrical energy to a low voltage format suitable for solid state signal processing equipment. The supply entails in succession bridge rectification means, a dc-dc boost converter, a capacitor storage bank, and a half bridge converter, either resonantly or non-resonantly operated. The converters operate at frequencies substantially above audible frequencies in the interests of compactness. The design provides a high input power factor (inductive) with minimum EMT, and provides a lengthened voltage hold up after loss of power.
Abstract:
Reduced-power dynamic data circuits with wide-band energy recovery are described herein. In one embodiment, a circuit system comprises at least one sub-circuit in which at least one of the sub-circuits includes a capacitive output node that is driven between low and high states in a random manner for a time period and an inductive circuit path coupled to the capacitive output node. The inductive circuit path includes a transistor switch and an inductor connected in series to discharge and recharge the output node to a bias supply. A pulse generator circuit generates a pulse width that corresponds to a timing for driving the output node.
Abstract:
In a resonant motor system, an electrical motor having a stator with one or more windings, a rotor which may or may not be wound, and an air gap between the stator and the rotor for storing magnetic energy such that the motor exhibits a definite electrical inductance may be deployed with a drive combination including a capacitance connected in series with the inductance of the motor to form an LCR circuit therewith. Phased provision of DC power to the LCR circuit causes the circuit to oscillate, which excites the motor. The DC power is provided in synchronism with the rotation of the rotor in order to maximize torque produced by the motor.
Abstract:
An inverter device for supplying a stable, high power-factor input current while restraining higher harmonics to be low is provided by a simple circuit structure in which a pulsating DC voltage supplied through a power circuit is provided to a smoothing condenser, a direct current is provided from the smoothing condenser to an inverter circuit section, and an input current path is formed from the power circuit through an impedance element to a switching element of the inverter circuit section and to part of an oscillation circuit.
Abstract:
A power supply for arc processing which can be used with a commercial AC power supplying either a high or low voltage, with the low and high voltages having a ratio of 1:2. The power supply includes two or three rectifying circuits connected in parallel, each of which comprises three series diodes, with a first series connection point of each series connected diodes being connected to one of the input terminals (phases) of the commercial power supply. The power supply further includes two or three voltage change over circuits, comprising a capacitor and a voltae change-over switch, closed at a low voltage input, connected between a second connection point of its corresponding rectifying circuit and the first connection point of another rectifying circuit. An inverter circuit for inverse conversion is connected in parallel between the terminals of the three rectifying circuits.
Abstract:
A high frequency converter of push-pull form comprises a center tapped D.C. input supply 16, 17, 18, two solid state switching devices (20, 21) connected in series across the D.C. input terminals, a load circuit including a supersonic frequency transformer 30 and an output rectifier 35, and an oscillatory circuit including at least one capacitor 40 and a parallel inductor 34 connected in parallel with the primary winding 37 of the transformer between the center tapping 19 of the supply and the junction 25 of the switching devices. The switching devices are synchronized to the oscillation of the oscillatory circuit to allow the circuit to oscillate freely for part of a cycle to transfer energy from the inductor 34 to the capacitor 40 to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then connect the parallel inductor across the D.C. input terminals whereupon the parallel inductor receives and stores energy from the said supply. Means such as a saturable reactor 33 are connected in series in the load circuit to restrict load current to a low value during a part of the cycle in which the capacitor receives energy from the parallel inductor and until the capacitor is charged to the said condition and the switching means has connected the load circuit across the supply.