Patents by Inventor Leland M. Farrer

Leland M. Farrer 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).

  • Patent number: 6133699
    Abstract: A system for operating a plurality of motors with a single controller is disclosed. This system includes a first motor, a second motor that is matched to the first motor but has a lower power rating than the first motor and a controller electrically driving the first and second motors with a modulated voltage at one frequency selected from one or more frequencies over a complete range of frequencies. The controller generates a frequency of the modulated voltage from the range of frequencies which is proportional to the desired speed for the first and second motors. A method for building such a system is also disclosed. This system and method have particular application to HVAC systems.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: October 17, 2000
    Assignee: Gas Research Institute
    Inventors: Nick G. Vrionis, Robert M. Russ, Dave Blau, Leland M. Farrer
  • Patent number: 5990640
    Abstract: An H-Bridge motor controller having a floating, electrically isolated high side FET driver design where the motor driver circuity is electrically isolated from the logic circuitry. Back EMF generation during motor operation is minimized by employing a "fifth" power transistor to the H-Bridge that connects the motor coil to ground when the other transistors in the H-Bridge are turned off, so as to provide a direct path for the unused energy to be removed from the driver circuit without interfering with the normal switching of the FETs. Alternatively, back EMF generation is minimized by applying switching signals to the H-Bridge where, instead of turning the low side FET drivers between motor clocks, the low side FET drivers are both turned on during the "off time" period, so as to connect both ends of the motor coil to ground during the "off" period, thereby draining the coil of unused energy.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: November 23, 1999
    Assignee: Aim Controls, Inc.
    Inventors: Patrick H. Dwyer, Leland M. Farrer, Martin Mason
  • Patent number: 5909640
    Abstract: A wireless communication system with one or more remote transceivers for transmitting a wireless data signal at an actual frequency that is different than the expected frequency and a base transceiver that can automatically adjust to receive the actual frequency. Each remote transceiver is adapted to initiate a wireless data signal at a selected time that is unique to that remote transceiver. The expected frequency is sequentially pre-determined in a pseudo-random sequence with each remote transceiver having a unique sequence. The base transceiver can respond to the remote transceiver at the actual frequency. Both the remote transceiver and the base transceiver can convert the wireless signals in a single step to baseband.
    Type: Grant
    Filed: October 6, 1997
    Date of Patent: June 1, 1999
    Assignee: Whisper Communications, Inc.
    Inventors: Leland M. Farrer, Joseph S. Chan, Robert F. Garry, Jr., Charles A. Glorioso, Norman F. Krasner
  • Patent number: 5734966
    Abstract: A wireless communication system with one or more remote transceivers for transmitting a wireless data signal at an actual frequency that is different than the expected frequency and a base transceiver that can automatically adjust to receive the actual frequency. Each remote transceiver is adapted to initiate a wireless data signal at a selected time that is unique to that remote transceiver. The expected frequency is sequentially pre-determined in a pseudo-random sequence with each remote transceiver having a unique sequence. The base transceiver can respond to the remote transceiver at the actual frequency. Both the remote transceiver and the base transceiver can convert the wireless signals in a single step to baseband.
    Type: Grant
    Filed: January 20, 1995
    Date of Patent: March 31, 1998
    Assignee: Diablo Research Corporation
    Inventors: Leland M. Farrer, Joseph S. Chan, Robert F. Garry, Jr., Charles A. Glorioso, Norman F. Krasner