U.S. Philips Corporation

Jan Tiesinga

Peter Sofrides Viet

Jacobus N Dekker

Albert J Meijer

Ate K Damstra

Michiel A Schallig

Johannes At Driessen

Albertus J Van Der Borst

Paul A Beijer

Wieger Lindeboom

The invention relates to an electrical surface treatment device which is provided with an acoustic surface type detector with which a type of a surface to be treated can be detected during operation. According to the invention, the surface type detector delivers an output signal (u.sub.FT) during operation which is characteristic of the type of surface to be treated and which is determined by a value of a physical quantity of air vibrations reflected by the surface to be treated, which value is measured by a vibration detector of the surface type detector. In a special embodiment, the physical quantity is an amplitude, and the surface type detector is a vibration generator for generating air vibrations having a predetermined amplitude. The generated air vibrations preferably have a frequency of at least 15,000 Hz which varies within a predetermined range. In a further embodiment, the vibration generator generates the air vibrations intermittently, and the surface type detector is a parallel circuit through which a portion of the generated air vibrations can be directly guided to the vibration detector.

Electrical surface treatment device with an acoustic surface type

Power-supply and communication

A shaving apparatus (1, 101, 201) is provided which includes at least one cutting unit (11) which is provided with an external cutting member (13) with at least one hair trap opening (17) and with an internal cutting member (19) which is rotatable in the external cutting member (13) by means of an electric motor (23). The speed of the motor (23) can be controlled during operation by a feedforward control unit (43, 103, 203) as a function of at least one physical quantity which can be measured during operation by means of a transducer (59, 69, 111). A first embodiment of the shaving apparatus (1) comprises a timer (59) which measures a time which has elapsed during a shaving operation, and a detector (69) with a microphone (71) which measures a cutting frequency of the cutting unit (11), the speed of the motor (23) being controllable by the control unit (43) as a function of the time which has elapsed during the shaving operation and of the cutting frequency. A second embodiment of the shaving apparatus (101) comprises a force detector (111) which measures a skin contact force exerted on the cutting unit (11), and again a detector (69) with a microphone (71) measuring a cutting frequency of the cutting unit (11), so that the speed of the motor (23) can be controlled by the control unit (103) as a function of the skin contact force and the cutting frequency. In a special embodiment, the control unit (43, 103, 203) controls the speed of the motor (23) in accordance with an algorithm based on fuzzy logic. The shaving apparatus (1, 101, 201) provides a user of the shaving apparatus (1, 101, 201) with an optimum balance between shaving performance, shaving comfort and power consumption of the motor (23) during a shaving operation.

Shaving apparatus with controllable motor speed

A vacuum cleaner is provided which has a motor housing (2) and a hose (8), which can be coupled via two mains-voltage wires (38, 42), one communication wire (48) and contacts (32, 34, 30). The motor housing (2) and the handle (10) of the hose (8) include microprocessors (6, 12) which communicate with one another via the communication wire (48). The first reference signal (26) of the one microprocessor (6) is connected to the one mains voltage terminal (18) and the second reference signal (44) of the other microprocessor (12) is connected to the other mains voltage terminal (40).

Vacuum cleaner with three-wire power-supply and communication connection

Growing community of inventors

Drachten, Netherlands

Jan Tiesinga