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A laminated-core parametric motor has advantageous features and a planar structure that make it possible to reduce the mass-production costs of the motor. In past work, we presented the practicality of applying a two-dimensional reluctance network model using variable reluctances that enabled dynamic analysis of a motor while the rotor was spinning. We investigated how to improve the analytical accuracy of the reluctance network model of the motor by using parameters δ.

A laminated core parametric induction motor has desirable features and the planer structure to make it possible to reduce the production cost of the motor by mass production. In the past work, we showed the validity to apply the two-dimensional reluctance network analytical model to the dynamic analysis of the motor while the rotor is driving. In this paper, we investigate the improvement the accuracy of the analytical method of the motor by using new reluctance network analytical model of the motor. In this model, the magnetic circuits of the stator and the rotor are connected by the variable reluctances that are expressed as the function of the rotating angle.

The operating characteristics of parametric transformers and dc-ac converters with an orthogonal core depend heavily on the core shape. Accordingly, to obtain the optimal design for such devices, the quantitative relationship between the orthogonal core shape and the operating characteristics of the application device are determined. In this paper, the application characteristics are discussed analytically in terms of the orthogonal core shape, with reference to a magnetic circuit model of the core.

The operating characteristics of parametric transformers and dc-ac converters with an orthogonal core greatly depend on the core shapes. Accordingly, in the optimal design for the applications, we used to clarify the quantitative relationship between the orthogonal-core shape and the operating characteristics of the application devices. In this paper, the application characteristics in terms of the orthogonal-core shape are discussed analytically with reference to a magnetic circuit model of the orthogonal core.

The orthogonal-core has various applications such as a parametric transformer and a DC-AC converter. The operating characteristics of the application devices can be calculated based on the measured flux-MMF relationship of the orthogonal-core. For the optimum design of the applications, we have to predict the flux-MMF relationship. However, in order to calculate the relationship, we need to solve the three-dimensional nonlinear problem. In this paper, we calculate the flux-MMF relationship based on the magnetic circuit model of the orthogonal-core. The computed results agree well with the experimental ones. It is obvious that the method on this study is valid for the calculation and useful for the optimum design of the applications.

This paper describes an analysis of the behavior of orthogonal-core type push-pull parametric transformers, taking the iron loss of the orthogonal-cores and the copper loss of the windings into consideration. The analysis was performed for the magnetic circuit of the orthogonal-core under magnetic saturation and with hysteresis. To improve the accuracy of calculations, the saturation characteristic was approximated by a series which includes terms of up to 21st order in the flux, and the hysteresis curve by a series including terms of up to 5th order in the exciting voltage. The calculated results show good agreement with experimental data. The analytical method presented here is useful for optimizing the design of push-pull parametric transformers.

A laminated core parametric induction motor utilizing a parametric oscillation has a flat and slotless structure suitable for mass-production. This paper analyzes the laminated core parametric induction motor when the rotor is driving by the use of a three dimensional reluctance network model. The dimensions and materials of the motor were also shown. An analytical model of the rotor is constituted of the electrical circuit to evaluate the induced currents on the rotor bar and end ring and the magnetic circuit to express the MMFs corresponding the induced currents on the rotor.

In this study, the capacitance of capacitors connected in series with the auxiliary winding of a capacitor motor was changed by switching the firing angle of the triac, and ferrite magnetic wedges were inserted into the stator slots to reduce the flux density distortion in the air gap.

The authors have inserted ferrite magnetic wedges into the stator slot openings of the capacitor motor to decrease the pulsation of flux density distribution in the air gap. As a result, the iron loss was reduced greatly to increase the motor efficiency and to improve other running characteristics.

The split-phase condenser motor is very useful for driving home electric appliances, but it has low efficiency. In other words, since the condenser motor is operated by two magnetic fields constituting positive phase and negative phase sequences, large electric power losses in light loads and oscillative torque are usually produced. In addition to this, the presence of the slot embedding electric conductors disturbs the flux density distribution in the air gap, producing tooth pulsation and higher harmonic losses. In this study, ferrite magnetic materials have been wedged into the stator slot openings of the condenser motor to smooth the pulsative distribution of the flux density in the air gap, and some experiments have been carried out to discuss the effect of the ferrite wedges on the motor characteristics with various running condenser capacities. As a result, the usefulness of the ferrite magnetic wedge has been verified.

Split-phase capacitor motors are commonly used to drive household electric appliances. The motor has some slots and teeth to embed electric conductors or coils. The presence of the slots and teeth induces the variation of magnetic reluctance through the magnetic circuit to introduce heavy pulsation of the air gap flux. Thus, the voltage, current and torque of the motor become oscillative to increase the electric power loss and finally to reduce the motor efficiency. First, the authors discuss the characteristics of a 3-phase cage-type induction motor in which the ferrite magnetic wedges have been installed into the stator slot openings of the motor to smooth the air gap flux pulsation and to decrease the electric power loss, resulting in improved motor efficiency. If the motor is driven by the voltage source in accordance with the loading condition, more economical operation will be achieved. In this study, a nonsinusoidal voltage controlled by the switching element of a triac has been applied to a capacitor motor with wedges of ferrite magnetic materials. This paper reports on the interesting results obtained.

Low-loss polarisation-maintaining fibres, with the zero dispersion wavelength shifted to 1.56 ?m, have been fabricated. A minimum transmission loss of 0.27 dB/km and crosstalk of ?22dB over a length of 4.1km, corresponding to h = 1.53 × 10-6m-1, are achieved at the same wavelength.