Power Feeding Circuit Research Articles

CIRCUIT SOLUTIONS OF SEPARATE CASCADES OF THE TRANSMISSION PATH OF THE ATMOSPHERIC OPTICAL COMMUNICATION LINE

The article contains the circuits useful for modulation of the light emission diodes by the power feeding circuit in order to make the powerful light source for the purposes of constructing Atmosphere Optical Connection Line with the transfer rate 1-4 M bit per second. Discussed the differences of circuitry for single LEDs of different power and the possibility and usefulness of the sequential LED circuits.

Traveling wave current drive theory for an arbitrary m-polar configuration

An extension of the formalism employed to describe current drive in magnetized plasmas by means of traveling magnetic fields (or double-helix configuration) is presented. In all previous theoretical studies, only driving fields with dipolar topology have been employed and the figure of merit of the current drive mechanism has never been analyzed in terms of the dissipation in the power feeding circuit. In this paper, we show how to express the model equations in terms of the current amplitude in the coils, for an arbitrary number of equally spaced coils wound around the plasma column. We present a brief review of the existing theory and a theoretical formulation, valid for an arbitrary m-polar helical symmetry, which removes the above mentioned complications and limitations. In the limit of straight coils, our magnetic field expression agrees exactly with well-established results of the literature for rotating magnetic field current drive. Finally, we present initial numerical results from a recently developed code which consistently compares the steady driven nonlinear Hall currents and steady fields, corresponding to different configurations in terms of the Ohmic dissipation in the helical coils and discuss future perspectives.

Frequency Characteristics of the MAGLEV Double-layered Propulsion Coil

The MAGLEV (magnetically levitated vehicle) is now well along in development testing at Yamanashi Test Line. The MAGLEV power source needs to supply a variable voltage and variable frequency to propulsion coils, which installed on outdoor guideway. The output voltage of the electric power converter contains many higher harmonics, which causes many troubles such as inductive interference. Accordingly, it is necessary to clarify the frequency characteristics of the propulsion coils and the power feeding circuit. In view of this situation, experiments and the theoretical analysis concerning the frequency characteristics of the propulsion coils with single-layer arrangement and the power feeding circuit at Miyazaki Test Line had been performed by the author. But the arrangement of the propulsion coils had been changed in Yamanashi Test Line from the single-layered coils to the double-layered coils for the stability of the super-conducting magnet on board. Thus, experiments and investigations concerning the frequency characteristics(resonance characteristics)of the propulsion coils with double-layer arrangement at Yamanashi Test Line have been performed but a theoretical analysis had not been done enough. A theoretical analysis was therefore done in this paper by applying the inverted L equivalent circuit with mutual inductance and capacitance to the propulsion coil, from which the positive and zero phase characteristics of the double-layered propulsion coils were analyzed.

Operation Performance of Self-Oscillation Ultrasonic Vibrating Device for Liquid Atomization

An ultrasonic vibrating device, composed of a rectangular piezoelectric ceramic plate and a metal plate is described for liquid atomization. The resonance is used for the self-oscillation, which arises from the coupling between two vibration modes in the ceramic plate. The best operation occurs when one of the resonant frequencies of the vibrating device is equal to that of the piezoelectric ceramic plate without the metal plate. The ceramic plate has two electrodes on one of the two surfaces. A power feeding circuit is composed of the piezoelectric ceramic plate with three electrode terminals, which functions as a resonant element as well as a vibration source, and a power amplification transistor. The metal plate with minute holes functions effectively for liquid atomization.

A Self-Oscillation-Type Ultrasonic Linear Actuator

A cylindrical piezoelectric ceramic vibrator with two half-moon-shaped electrodes on a flat surface is described as a key device for constructing a linear actuator. The unidirectional mechanical force, arising from two coupled vibration modes, on the side surface of the ceramic column plays the role of a stator for the actuator operation. A practical power-feeding circuit composed of the piezoelectric ceramic column with three electrode terminals and a transistor for power amplification is demonstrated successfully under a stable, continuous actuator operation. The size of the ceramic vibrator used for the present linear actuator is 10 mm in diameter and 10 mm in length. The directionality of linear actuator operation is changeable. The response time to the steady state from zero is on the order of ms.

Impedance frequency characteristics of MAGLEV power feed circuits

AbstractIn Japan, the MAGLEV (magnetically levitated train) is now well along in development testing. The MAGLEV power source must supply a variable voltage and variable frequency source, and contains many higher harmonics which cause many problems such as inductive interference. Thus it is necessary to clarify the impedance frequency characteristics of the MAGLEV power feed circuit.In view of this situation, experiments and investigations concerning the impedance frequency characteristics of the coils for propulsion and the power feeding circuit at the Miyazaki Test Track have been performed but no theoretical analysis has been done.Thus a theoretical analysis was performed in this paper by applying the inverted L equivalent circuit to the coil for propulsion, from which the characteristics of the coils for propulsion were analyzed.In addition, the characteristics of the power feeding circuit could be clarified by assuming the equivalent circuit of the power feeder line.As a result, the measured values and calculated values were almost equal in both the characteristics of the coils for propulsion and those of the power feeding circuit.

The Impedance Frequency Characteristics of the MAGLEV Power Feeding Circuit.

The MAGLEV (magnetically levitated train) is now well along in development testing in Japan. The MAGLEV power source needs to supply a variable voltage and variable frequency source, and contains many higher harmonics, which causes many troubles such as inductive interference. Thus it is necessary to clarify the impedance frequency characteristics of the MAGLEV power feeding circuit. In view of this situation, experiments and investigations concerning the impedance frequency characteristics of the coils for propulsion and the power feeding circuit at the Miyazaki test track have been performed but a theoretical analysis had not been done.A theoretical analysis was therefore done in this paper by applying the inverted L equivalent circuit to the coil for propulsion, from which the characteristics of the coils for propulsion were analyzed.In addition the characteristics of the power feeding circuit could be clarified by assuming the equivalent circuit of the power feeder line.As a result, the measured values and calculated values were almost equal in both the characteristics of the coils for propulsion and those of the power feeding circuit.

Special Problems in Transistorized Repeater Design for Long-Haul Systems

When the change is made from tubes to transistors, the repeaters can be buried in the ground, which makes temperature control possible such that after about ten temperature-controlled repeaters, a pilot-controlled repeater will be used. Although a system with buried repeaters makes it difficult to locate a fault, this can be done by a pulsed carrier operating above the useful band and returning to the input point at each repeater via special filters connecting both directions. When the power-feeding circuit is interrupted, the origin of the fault can then be tracked down by resistance measurement. Transistor repeaters require efficient protection with respect to induced extraneous voltages, e.g., by gas-discharge tubes and diodes.