An electric toothbrush (26) includes a motor (30) and a mechanical oscillator (32) for driving a brush head assembly (24) at high frequencies. The brush head assembly (24) attaches to the mechanical oscillator (32). A motor (30) drives the brush head assembly (24). Control circuitry (34) senses the frequency of oscillation of the mechanical oscillator (32) and controls the frequency of the power applied to the motor (30) to maintain the mechanical oscillator (32) at resonance under a variety of loads imposed during use.

High frequency electric toothbrush

An oral hygiene device (2) is disclosed having at least two motors (30, 36) to simultaneously vibrate and impart motion upon the head portion of the oral hygiene device (2), most beneficially at the tip (12). A first motor (30) is positioned in the handle housing (3) of the device (2) to impart a first frequency of movement to the tip (12). A second motor (36) is located in a head portion, generally in a shaft (8) of or an oral hygiene attachment to the device (2), to impart at least a second frequency of movement onto the tip (12). When both the first and second motors (30, 36) are activated, the resulting movement of the tip (12) of the device (2) may include complex, substantially random movements, depending in part on the frequencies at which the motors (30, 36) are operating.

Dual motor oral hygiene device

An oral hygiene device is disclosed having at least two motors to simultaneously vibrate and impart motion upon the head portion of the oral hygiene device, most beneficially at the tip. A first motor is positioned in the handle portion of the device to impart a first frequency of movement to the tip. A second motor is located in a head portion, generally in a shaft of or an oral hygiene attachment to the device, to impart at least a second frequency of movement onto the tip. When both the first and second motors are activated, the resulting movement of the tip of the device may include complex, substantially random movements, depending in part on the frequencies at which the motors are operating.

Characterization of motion of dual motor oral hygiene device

A sonic toothbrush system including an electric motor, a brush shaft, a drive assembly, a fluid conduit connected to a pressurized, pulsed water source, and a water jet nozzle positioned on the brush head and connected to the fluid conduit. The electric motor includes a drive shaft. When the electric motor is caused to operate, the drive shaft continuously rotates until the motor is caused to stop. The drive assembly is coupled between the drive shaft and brush shaft. The drive assembly is configured to convert the rotation of the drive shaft into sonic oscillation of a toothbrush supported on an end of the brush shaft. The drive assembly further forms part of the fluid conduit to deliver a pulsed water stream to the jet nozzle.

Mechanically driven, sonic toothbrush and water flosser

A sonic toothbrush system includes an electric motor, a brush shaft, and a drive assembly. The electric motor includes a drive shaft. When the electric motor is caused to operate, the drive shaft continuously rotates until the motor is caused to stop. The drive assembly is coupled between the drive shaft and the brush shaft. The drive assembly is configured to convert the rotation of the drive shaft into sonic oscillation of a toothbrush head supported on an end of the brush shaft.

Mechanically-driven, sonic toothbrush system

In a magnetic floating type of super high speed transportation system using a linear synchronous motor system as its drive system in which a field magnet is carried on a train and a series of armature coils are provided along a track, a speed of a train is regulated under control of a frequency converter of the variable frequency and voltage type for supplying power to the armature coils. For the speed regulation, a relative position of the field magnet to the armature coils is detected to form a train of position detecting pulses. A reference frequency pattern with a frequency corresponding to a speed command is formed. A phase difference between the reference frequency pattern and the position detecting pulse train is detected. A propulsion force command of a linear motor is obtained by setting different limit values in the positive and negative parts of the phase difference signal. A sinusoidal current waveform pattern is formed in synchronism with the position detecting pulse train. By multiplying the current waveform pattern by the propulsion force command, a sinusoidal armature current pattern is obtained of which the frequency and the crest value are fixed. The cycloconverter is controlled so as to provide an armature current following the armature current pattern, whereby the vehicle speed accurately follows the speed command.

Control system for a linear synchronous motor

Maglev vehicle ML-500 in Japan attained a speed of 517 km/h on December 21, 1979. The linear synchronous motor (LSM) drive cycloconverter fabricated and submitted to the track test has a capacity of approximately 12 000 kVA in a continuously variable frequency range of 0-34 Hz with a sinusoidal current waveform. The current can be arbitrarily controlled in a range of 200-1300 A. Despite the rigorous power conversion and control, excellent current control characteristics were obtained: less than 4 percent in deviation of current peak value, about 4 ° in leading phase deviation and approximately 1.2 ms in zero current interval. Some observations about the LSM driving system are made, and an outline of the design and the data obtained from the super-high-speed running tests on Miyazaki test track are given.

Characteristics of Linear Synchronous Motor Drive Cycloconverter for Maglev Vehicle ML-500 at Miyazaki Test Track

https://www.jstage.jst.go.jp/article/ieejpes1972/101/11/101_11_635/_pdf

Takashige Saijo

Papers

Control system for a linear synchronous motor

Characteristics of Linear Synchronous Motor Drive Cycloconverter for Maglev Vehicle ML-500 at Miyazaki Test Track

Reactive Power Compensation of Cycloconverters using Circulating Current Control

Analysis of the Input Current of the Reactive Power Compensated Cycloconverter

Regelanordnung fuer einen linearen synchronmotor