Hideki Ted Kawaji

US Patent:

6741049, May 25, 2004

Filed:

Oct 28, 2002

Appl. No.:

10/282921

Inventors:

Hideki Ted Kawaji - Bedford NH
Mark R. White - Andover NH

Assignee:

Melexis NV Miroelectronics Integrated Systems - Ypres

International Classification:

H02P 118

US Classification:

318254, 318138, 318439, 318459, 318500, 388928, 3889281, 388923

Abstract:

A local oscillator and logic circuit pulses the open winding of a brushless DC motor at start up and the back EMF is used to generate a voltage to boost the voltage available to the control circuit for optimizing performance when starting with low supply voltage. As the rotor of a motor rotates and the windings are commutated by the drive electronics there is generated in each winding a voltage caused by the collapse of the current and the inherent inductance of the winding. These voltages exceed the normal operating voltage of the motor. The energy in these voltages is used to generate a regulated power feed to the analogue circuitry of the control circuit at a suitable voltage level. During steady state conditions, when the motor is running, the commutation of the windings is continual and there is ample energy available to power analogue electronics, and, if required, associated digital electronics as well. At start up, however, when the motor is stationary, there is no commutation and thus no additional voltage pulses from which to generate a supply for the analogue circuitry. Accordingly, additional circuitry is included to drive one of the motor windings with short voltage pulses such as to create inductive voltages that can be used to create the desired regulated power feed for the analogue circuitry.

US Patent:

20110312371, Dec 22, 2011

Filed:

Jun 18, 2010

Appl. No.:

12/818244

Inventors:

Hideki Kawaji - Bedford NH, US

International Classification:

H04W 88/02
H04M 1/00

US Classification:

4555501

Abstract:

A mis-function protection method for mobile phones from RF noise interference includes the steps of: a signal detection circuit provided in a mobile phone, the signal detection circuit being operated to periodically detect a RF signal with a predetermined time period to determine outputting a signal; when firstly detecting no RF signal, no signal output from the signal detection circuit, alternatively when firstly detecting a RF signal, the signal detection circuit being operated to secondly detect the firstly-detected RF signal after a predetermined time; and when secondly detecting none of the firstly-detected RF signal, no signal output from the signal detection circuit, alternatively when secondly detecting the firstly-detected RF signal, the signal detection circuit being operated to output the signal.

US Patent:

49356984, Jun 19, 1990

Filed:

Mar 3, 1989

Appl. No.:

7/318265

Inventors:

Hideki Kawaji - Andover NH
Peter J. Gilbert - Henniker NH

Assignee:

Sprague Electric Company - North Adams MA

International Classification:

G01B 714
H01L 4306

US Classification:

32420720

Abstract:

A Hall elements and magnet assembly for use as a proximity detector includes a magnet, a pole piece mounted to one pole end of the magnet and an integrated circuit having two side-by-side Hall elements, an amplifier, interconnecting wiring providing the difference voltage between the two Hall output voltages at the input of the amplifier, and a Schmitt trigger circuit. The integrated circuit is mounted to the pole piece at the pole end of the magnet. The pole piece is a ferromagnetic member which is thinner in the center than at the periphery for achieving a highly uniform field strength across the surface of the magnet pole end toward reducing the criticality of the position of mounting of the integrated circuit in manufacturing and for extending the range of gap dimensions between a passing ferromagnetic article and the assembly for which proper detection of the passing article can be made to occur. The term "ferromagnetic" as used herein means any material with a relative permeability greater than unity and preferably greater than 100.

US Patent:

47514639, Jun 14, 1988

Filed:

Jun 1, 1987

Appl. No.:

7/056167

Inventors:

Jacob K. Higgs - Salisbury NH
Hideki Kawaji - Franklin NH
Ravi Vig - Concord NH

Assignee:

Sprague Electric Company - North Adams MA

International Classification:

G05F 326

US Classification:

323314

Abstract:

An integrated circuit voltage regulator is of the kind having a pass transistor connected collector-to-emitter between the input V. sub. CC conductor and the regulated-voltage output conductor, a current source circuit supplying a base bias current to the pass transistor and a voltage reference and feedback regulator circuit connected between the output voltage conductor and the base of the pass transistor. A protective circuit against high voltage transients adding to V. sub. CC voltage comprises a transistor connected collector-to-emitter between the pass-transistor base and ground has a resistor paralleling the base-emitter junction, which resistor is resistively coupled to the input V. sub. CC line to shunt away the pass-transistor bias current whenever the V. sub. CC voltage level exceeds a value just under the latch-back breakdown voltage of the pass transistor.