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 device for detecting the presence of water includes a capacitance sensor coupled to a windshield to detect capacitance changes A multivibrator is coupled to the sensor to translate the detected capacitance change to the frequency domain A phase-locked loop coupled to the multivibrator produces a phase pulse in response to water causing a change in capacitance and, in turn, a change in the frequency of the multivibrator

Proximity moisture sensor

A synchronous motor is driven by applying cyclical or digital data through a phase locked loop whose loop filter integrates with a time constant equal to or greater than the inertial delay of the motor from start to its operating speed. According to one embodiment, the frequency output of the phase locked loop is further controlled with a digital rate multiplier whose phase effects are minimized by operating the VCO at a multiple of the input frequency and feeding the VCO voltage back through a frequency divider. According to another embodiment, the frequency control is obtained with a preliminary phase locked loop with a normal filter but a high frequency VCO whose feedback is divided by a value n, and then dividing the output of the main loop by m. Suitable counters may be used to stop and start the drive.

Synchronous motor drive

In the disclosed system if the frequency of input signals exceeds a value suitable for a load, the input signals and output signals are stored and compared in a comparator while locking of a phase locked loop is delayed by a loop filter that allows the output of the VCO (voltage controlled oscillator) to increase or decrease only at rates slower than given rates. When the input signals end after the loop locks, the filter delay causes the VCO to keep producing output signals which are passed until the comparator recognizes that the number of output signals equals the number of input signals. If the input signals end before the loop locks, a logic circuit causes the VCO frequency to keep rising until another comparator indicates that the number of output signals has reached one-half the input signals.

Leopold Bric

Papers

Synchronous motor drive

Phase locked loop control system