Patents by Inventor David Coutu

David Coutu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method and apparatus for eliminating stall and cogging in multi-phase stepping motors
    Patent number: 7495409
    Abstract: The lead or lag relationship between the stator and rotor of a stepper motor is monitored on a continuing basis by an incremental encoder, in feed-back relation, and adjusts the lead or lag to within optimum range values to thereby prevent motor stalls and motor cogging.
    Type: Grant
    Filed: October 30, 2006
    Date of Patent: February 24, 2009
    Inventor: David Coutu
  • Method and apparatus for eliminating stall and cogging in multi-phase stepping motors
    Publication number: 20080100249
    Abstract: The lead or lag relationship between the stator and rotor of a stepper motor is monitored on a continuing basis by an incremental encoder, in feed-back relation, and adjusts the lead or lag to within optimum range values to thereby prevent motor stalls and motor cogging.
    Type: Application
    Filed: October 30, 2006
    Publication date: May 1, 2008
    Inventor: David Coutu
  • Thermally efficient motor housing assembly
    Patent number: 7242593
    Abstract: A thermally efficient motor housing assembly including a plurality of transistors and a printed wire board (pwb) for controlling a stepper motor and also including a plunger array and a spring array along with a combined heat sink and pwb enclosure.
    Type: Grant
    Filed: July 8, 2005
    Date of Patent: July 10, 2007
    Assignee: IMS Inc.
    Inventor: David Coutu
  • Thermally efficient motor housing assembly
    Publication number: 20070008707
    Abstract: A thermally efficient motor housing assembly including a plurality of transistors and a printed wire board (pwb) for controlling a stepper motor and also including a plunger array and a spring array along with a combined heat sink and pwb enclosure.
    Type: Application
    Filed: July 8, 2005
    Publication date: January 11, 2007
    Inventor: David Coutu
  • Method to prevent midrange resonance during operation of a multi-phase step motor
    Patent number: 7154245
    Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for preventing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to prevent the excitation of system harmonics and prevent step motor operational instability.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: December 26, 2006
    Assignee: IMS Inc.
    Inventors: David Coutu, Robert A. Fournier
  • Method to prevent midrange resonance during operation of a multi-phase step motor
    Publication number: 20060108965
    Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for preventing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to prevent the excitation of system harmonics and prevent step motor operational instability.
    Type: Application
    Filed: December 20, 2005
    Publication date: May 25, 2006
    Inventors: David Coutu, Robert Fournier
  • Method for driving a high side P-CHANNEL MOSFET
    Patent number: 6897706
    Abstract: A P-CHANNEL MOSFET is configured as a high side switch by arranging a capacitor between the P-CHANNEL MOSFET gate and a pair of push/pull transistors in a control circuit. A pull-up resistor is connected with the high side supply, one leg of the capacitor and with the gate of the P-CHANNEL MOSFET. In a two-phase electrical drive circuit, a pair of P-CHANNEL MOSFETS is connected with the high side supply and a pair of N-CHANNEL MOSFETS is connected with the low side supply.
    Type: Grant
    Filed: February 13, 2003
    Date of Patent: May 24, 2005
    Assignee: IMP Inc.
    Inventor: David Coutu
  • Method to reduce midrange resonance during operation of a multi-phase step motor
    Publication number: 20050088134
    Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for reducing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to reduce the excitation of system harmonics and prevent step motor operational instability.
    Type: Application
    Filed: October 22, 2003
    Publication date: April 28, 2005
    Inventors: David Coutu, Robert Fournier
  • Method and apparatus for independently controlling each phase of a multi-phase step motor
    Patent number: 6879128
    Abstract: The current in each phase of a multi-phase step motor is monitored and the excess phase current above the set point current, as required on a cycle-by-cycle PWM basis, is reduced thereby bringing each phase current down to the set point. The PWM frequency is automatically adjusted to maintain a minimum number of PWM edges within a portion of the current waveform. A maximum charge/discharge time is specified as a percentage of the PWM period. These provide an accurate independent current control within each phase of a multiphase step motor.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: April 12, 2005
    Assignee: IMS Inc.
    Inventors: David Coutu, Robert A. Fournier
  • Method and apparatus for improved low current accuracy in multi-phase step motors
    Patent number: 6867566
    Abstract: The sense signal, which is used to indicate that the motor phase current in a stepper motor is at the set point, is marked both before and after each pulse width modulator edge thereby reducing susceptibility to commutation noise from any phase. A mask time is created for a period before and after a PWM edge. The phase current is balanced during this mask time by removing and replacing the phase current.
    Type: Grant
    Filed: August 15, 2003
    Date of Patent: March 15, 2005
    Assignee: IMS Inc.
    Inventors: David Coutu, Robert A. Fournier
  • METHOD AND APPARATUS FOR IMPROVED LOW CURRENT ACCURACY IN MULTI-PHASE STEP MOTORS
    Publication number: 20050035736
    Abstract: The sense signal, which is used to indicate that the motor phase current in a stepper motor is at the set point, is masked both before and after each pulse width modulator edge thereby reducing susceptibility to commutation noise from any phase. A mask time is created for a period before and after a PWM edge.
    Type: Application
    Filed: August 15, 2003
    Publication date: February 17, 2005
    Inventors: David Coutu, Robert Fournier
  • Method and apparatus for independently controlling each phase of a multi-phase step motor
    Publication number: 20050024007
    Abstract: The current in each phase of a multi-phase step motor is monitored and the excess phase current above the set point current, as required on a cycle-by-cycle PWM basis, is reduced thereby bringing each phase current down to the set point. The PWM frequency is automatically adjusted to maintain a minimum number of PWM edges within a portion of the current waveform A maximum charge/discharge time is specified as a percentage of the PWM period. These provide an accurate independent current control within each phase of a multiphase step motor.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 3, 2005
    Inventors: David Coutu, Robert Fournier
  • Method for driving a high side P-CHANNEL MOSFET
    Publication number: 20040160266
    Abstract: A P-CHANNEL MOSFET is configured as a high side switch by arranging a capacitor between the P-CHANNEL MOSFET gate and a pair of push/pull transistors in a control circuit. A pull-up resistor is connected with the high side supply, one leg of the capacitor and with the gate of the P-CHANNEL MOSFET. In a two-phase electrical drive circuit, a pair of P-CHANNEL MOSFETS is connected with the high side supply and a pair of N-CHANNEL MOSFETS is connected with the low side supply.
    Type: Application
    Filed: February 13, 2003
    Publication date: August 19, 2004
    Inventor: David Coutu
  • Universal optically isolated input circuit
    Publication number: 20040075962
    Abstract: The invention comprises a printed circuit board having diode steering logic at the input and an optical coupler arrangement at the output thereof. A constant current source is arranged intermediate the diode steering logic and the optical coupler to maintain a constant current source to the optical coupler that is independent of input voltage.
    Type: Application
    Filed: May 15, 2002
    Publication date: April 22, 2004
    Inventor: David Coutu
  • Electric stepper motor having a cylindrical magnetic rotor with a pair of cups made of magnetic material
    Patent number: 6002186
    Abstract: An electric stepper motor includes a thru-hole, a rotor and a stator. The rotor consists of a pair of hollow magnetic metal flange-shaped laminations arranged within a hollow magnetic sleeve. The motor can be field-converted from rotary to lineal translation by attachment of a threaded nut to the motor shaft mounting face. The thru-hole allows use with a chamber and provides transport of hardware and elements into the chamber.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: December 14, 1999
    Assignee: IMS Inc.
    Inventors: David Coutu, Allen Bennett