Patents by Inventor Wayne R. Chism

Wayne R. Chism 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: 5003554
    Abstract: An automated apparatus and method for in-circuit testing of a coder/decoder circuit mounted a telecommunications card. The automated apparatus is capable of testing the functioning of the coder/decoder circuit: by applying at least one analog voltage signal to the transmit pin and recording the resulting digital serial output signals and by applying at least one pattern of digital signals to the digital serial input pin and recording the resulting analog signals on the receive pin. In conducting these tests, the automated apparatus electrically overdrives any analog or digital signal from associated components on the circuitry.
    Type: Grant
    Filed: July 19, 1988
    Date of Patent: March 26, 1991
    Assignee: Hewlett-Packard Company
    Inventor: Wayne R. Chism
  • Patent number: 4947113
    Abstract: A method and apparatus for providing pulse signals from a driver circuit in an in-circuit overdrive/functional tester to a probe, which tester provides a control signal representative of a command for the driver circuit to provide logic signals, includes adjusting the transition time of the logic signals so that the transition time is equal to twice the time it takes the pulse signal to travel from the driver circuit to the end of the probe and back. The method or apparatus for adjusting the rise time of the control signal can include adjusting the slew rate of the control signal. Pulse signals produced by such a method or apparatus have clean edges, have slew rates which are twice as fast as the slew rates of the driver signals and have zero propagation delay when measured at the fifty percent point.
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: August 7, 1990
    Assignee: Hewlett-Packard Company
    Inventors: Wayne R. Chism, Philip N. King
  • Patent number: 4947106
    Abstract: A device and process for programmatically controlled in-circuit pin checks and gross functionality tests of analog to digital converters. The tests provide deterministic bit checks for higher order bits and non-deterministic bit checks of lower order bits independent of other circuitry on the printed circuit board of which the digital to analog converter is a component.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: August 7, 1990
    Assignee: Hewlett-Packard Company
    Inventor: Wayne R. Chism
  • Patent number: 4888548
    Abstract: A device and process for programmatically controlled in-circuit pin checks and gross functionality tests of digital to analog converters. The tests provide deterministic bit checks for higher order bits and non-deterministic or "delta" bit checks of low order bits independent of other circuitry on the printed circuit board of which the digital to analog converter is a component.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: December 19, 1989
    Assignee: Hewlett-Packard Company
    Inventor: Wayne R. Chism
  • Patent number: 4860332
    Abstract: An automated apparatus and method for in-circuit testing of a subscriber line interface circuit mounted on a telecommunications card. The automated apparatus is capable of testing the functioning of the subscriber line interface circuit: by applying analog voltage to the tip and ring pins and recording the resulting transmit signals, by applying at least one analog voltage signal to the receive pin and recording the resulting signals on the tip and ring pins, by applying onhook and offhock signals to the tip and ring pins and receiving the resulting hook status signal, and by applying a ring command to the ring control pin and recording the resulting ring signal and then applying an offhook signal to the tip and ring pins and receiving the resulting ring trip signal. In conducting these tests, the automated apparatus electrically overdrives any analog or digital signal from associated components on the circuitry.
    Type: Grant
    Filed: July 19, 1988
    Date of Patent: August 22, 1989
    Assignee: Hewlett-Packard Company
    Inventor: Wayne R. Chism
  • Patent number: 4797627
    Abstract: A device and process for programmatically generated and controlled in-circuit pin tests and gross functionality tests of operational amplifiers. The tests provide basic functionality verification of amplifier functions independent of other circuitry on the printed circuit board of which the operational amplifier is a component.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: January 10, 1989
    Assignee: Hewlett-Packard Company
    Inventors: Wayne R. Chism, Larry G. Smeins