Patents by Inventor Walter L. Davis

Walter L. Davis 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: 4634956
    Abstract: A DC to DC converter includes a power input for receiving power at a predetermined input voltage. The converter is current-controlled to provide output power at a predetermined output voltage and several output current levels. The converter is further selectively controlled for either continuous or intermittent mode of operation. The continuous mode provides the higher output current levels and the intermittent mode provides the lowest output current level.
    Type: Grant
    Filed: January 10, 1985
    Date of Patent: January 6, 1987
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Michael J. DeLuca, William G. Siegel
  • Patent number: 4631737
    Abstract: An interface circuit is coupled between the last stage of an FSK receiver and a limiter to provide a biasing voltage signal to the limiter. The receiver includes a power saver circuit which supplies power on an interrupted basis. The interface circuit contains maximum and minimum detectors which derive and hold voltages corresponding to the maximum and minimum values of the discriminated signal from the receiver. These maximum and minimum corresponding voltages are averaged in a predetermined manner to provide the biasing voltage to the limiter. Thus, a proper bias voltage level can be accurately and quickly determined, and supplied to the limiter when power is supplied.
    Type: Grant
    Filed: December 6, 1984
    Date of Patent: December 23, 1986
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Yolanda Prieto, George W. Smoot
  • Patent number: 4628272
    Abstract: An inductorless quadrature demodulator for frequency modulated signals is disclosed. A limited FM signal is passed through an active filter (26) and a phase shift network (30) to produce a quadrature signal. The limited FM signal is compared with the quadrature signal in an EXCLUSIVE OR gate (24) and then low pass filtered (36) to obtain recovered audio. The active filter (26) includes a transconductance amplifier (60) whose center frequency can be adjusted by appropriate adjustment of the amplifier's bias current. The bias current is temperature compensated to allow operation of the demodulator over a wide temperature range.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: December 9, 1986
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Yolanda Prieto
  • Patent number: 4595885
    Abstract: An adjustable active filter includes a transconductance amplifier (60) and a current source (40, 42) which may be adjusted in value. The resonant frequency of the active filter may be adjusted upwards by increasing the bias current of the transconductance amplifier using a frequency trim up network (48). The resonant frequency may be adjusted downward by decreasing the bias current using a frequency trim down network (44). The trim is preferably accomplished by shorting out zener diodes (120, 122, 124, 126, 150, 152) which control the bias current of the transconductance amplifier.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: June 17, 1986
    Assignee: Motorola, Inc.
    Inventors: Yolanda Prieto, Walter L. Davis
  • Patent number: 4595972
    Abstract: This on/off power detector includes an input connected directly to a power source and input connected to the power source through a switch. The detector compares voltages on the two inputs to produce an output signal when the voltage on the switched input drops a predetermined amount below the voltage on the unswitched input, which is indicative of the switch being open. The detector is strobed on and off and only compares the input voltages to provide the output signal when it is in its strobed on condition.
    Type: Grant
    Filed: December 18, 1984
    Date of Patent: June 17, 1986
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Michael J. DeLuca
  • Patent number: 4591807
    Abstract: A low power, fast start up time crystal oscillator circuit has an amplifier portion powered from a one cell battery. The input stage of the amplifier portion is a common emitter amplifier circuit. A second stage includes a dual collector current mirror circuit having a current established at 3 times the input stage current. The output stage includes a current mirror circuit having a current established at 4 times the second stage current. A negative D.C. feedback circuit biases the amplifier portion. A single transistor interface circuit boosts and limits the output of the amplifier portion and permits the oscillator to drive other circuits that operate at higher voltages than the amplifier battery voltage.
    Type: Grant
    Filed: December 3, 1984
    Date of Patent: May 27, 1986
    Assignee: Motorola, Inc.
    Inventor: Walter L. Davis
  • Patent number: 4581632
    Abstract: An optical inspection system for articles moved by a conveyor, in which photo-electric transducers of one or more cameras are directed onto a transverse viewing area to detect light variations in individual articles. A threshold system permits correction for light signals in relation to the angular distance between the article being observed and the camera optical axis. A two-step inspection involves first detecting anomalous light levels, and subsequently detecting the size of each defect.
    Type: Grant
    Filed: February 8, 1985
    Date of Patent: April 8, 1986
    Assignee: Key Technology, Inc.
    Inventors: Walter L. Davis, Dale Messenger, Malcolm W. Randall
  • Patent number: 4527131
    Abstract: An MOS crystal controlled oscillator circuit is provided which includes a pair of MOS transistors coupled together in complementary fashion to form a first non-inverting stage. The output of the first non-inverting stage is coupled to the input of a second non-inverting stage including a MOS transistor exhibiting a source follower configuration or a bipolar transistor exhibiting an emitter follower configuration. The output of the second non-inverting source follower stage is coupled via a feedback element, for example, a piezoelectric crystal, to the input of the first non-inverting stage. A feedback loop is thus formed which causes the circuit to resonate at a frequency determined by the piezoelectric crystal feedback device. This oscillator configuration results in a degree of insensitivity to variations in parasitic impedance of the piezoelectric crystal feedback device.
    Type: Grant
    Filed: December 22, 1983
    Date of Patent: July 2, 1985
    Assignee: Motorola, Inc.
    Inventors: Barry W. Herold, Walter L. Davis
  • Patent number: 4520702
    Abstract: An article inspection and cutting apparatus (10) is described for high production processing of elongated articles (12) such as raw potato strips (french fries). The apparatus includes a conveyor (20) for moving the articles (12) in line in a large number of transversely spaced lanes past an inspection (28) station and a cutting station (30). Scanning cameras (38, 40) at the inspection station (28) rapidly scan across the lanes to detect color or shade variation in the articles (12) and generate electrical signals characteristic of the defect. Rotating sets of knife wheels (54) are positioned at the cutting station for selectively projecting two or more knives (68) from the periphery of the wheel to cut sections of the article (12) containing the defect to separate the defective portion from the remainder of the article. The apparatus 10 has the capability of detecting the size of different shade defects and removing smaller dark defects and larger lighter defects.
    Type: Grant
    Filed: May 27, 1983
    Date of Patent: June 4, 1985
    Assignee: Key Technology, Inc.
    Inventors: Walter L. Davis, Dale Messenger, Malcolm W. Randall
  • Patent number: 4518961
    Abstract: A battery powered, adaptive signal decoder is disclosed which is capable of processing detected encoded signals in accordance with a plurality of decoding schemes. The decoder has an equivalent microcomputer implementation. Energy conservation means operating independently of the detected signals acts to conserve the energy of the battery.
    Type: Grant
    Filed: January 30, 1984
    Date of Patent: May 21, 1985
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Kuppuswamy Raghunathan
  • Patent number: 4485912
    Abstract: An article alignment and conveying apparatus 10 is described for aligning elongated articles 12 in single file in a plurality of transversely spaced lanes and moving the articles while in the lanes past a work station 13. The apparatus 10 includes an article feed bed in the form of a series of stepped conveyor beds 20 for receiving the articles and subdividing the articles into a number of channels 32 corresponding with the lanes. The articles fall from the channels 32 onto a belt conveyor 40 having a plurality of parallel narrow belts extending from the channels 32 past the work station. The belt conveyor 40 has a grooved bed section for corrugating the surface formed by the belts to transversely space and longitudinally align the articles. The belt conveyor 40 has a second bed section that is flat to flatten the supporting surface of the belt as the aligned articles moved past the work station 13.
    Type: Grant
    Filed: June 1, 1982
    Date of Patent: December 4, 1984
    Assignee: Key Electrosonic Corporation
    Inventors: D. Murphy Carmichael, Walter L. Davis, Vernon L. Perry
  • Patent number: 4422162
    Abstract: A memory system is used to store data and is powered-up by and only during accessing signals, thus using essentially no current when not being accessed. The memory system includes a decoding network using a mixture of NPN and PNP transistors, and a buffer circuit at the input to a memory cell array allows the use of a minimum number of select lines, having low power requirements.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: December 20, 1983
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, Douglas R. Kraul
  • Patent number: 4414623
    Abstract: A dual deadman timer circuit functions to reset a dual mode microprocessor in the event of loss of program control. The microprocessor has high and low power requirements corresponding to its two operating modes, and the deadman timer circuit also adjusts the output power level of an associated two-level power supply to ensure that sufficient power is available for the full operation of the microprocessor during reset. The deadman timer functions during both microprocessor modes and includes two level-sensitive input sections to ensure that the microprocessor is reset under an error condition.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: November 8, 1983
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, James E. Jacobson, Jr.
  • Patent number: 4355277
    Abstract: A DC/DC converter operates at peak efficiency in either of two output current level states in response to the power demands of an associated electronic device, thereby reducing wasted current to a minimum. The converter is designed to operate from a one-cell battery, and is particularly suited to an integrated circuit implementation.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: October 19, 1982
    Assignee: Motorola, Inc.
    Inventors: Walter L. Davis, James E. Jacobson, Jr.
  • Patent number: 4329639
    Abstract: A highly accurate current mirror for IC implementation is comprised of low beta transistors and operates on a low supply voltage by utilizing a bias network with a balance sensing feedback network to control the bias voltage. The output current of one of the mirror transistors is compared with the reference current and the level of the current is then forced to equal the reference by means of the bias voltage adjustment.
    Type: Grant
    Filed: February 25, 1980
    Date of Patent: May 11, 1982
    Assignee: Motorola, Inc.
    Inventor: Walter L. Davis
  • Patent number: 4142177
    Abstract: The digital tone decoder system includes a phase locked loop which receives an input tone signal, which may be accompanied by noise, and produces a replica of the input signal from which the noise has been filtered. The tone signal operates a gate to pass clock pulses from a reference oscillator into a counter for precisely N cycles of the tone signal. The counter provides digital period information of the tone signal which is compared with period (frequency) information of the tone or tone sequence to which the detector system is to respond provided by an address code element. A logic control circuit is activated when lock is acquired by the loop, and this control circuit initiates operation of the other parts of the system and produces the detector output. The clock pulse oscillator also provides system timing and alert tone signals.
    Type: Grant
    Filed: August 12, 1976
    Date of Patent: February 27, 1979
    Assignee: Motorola, Inc.
    Inventor: Walter L. Davis
  • Patent number: 4083084
    Abstract: A crab meat removing machine is described to facilitate separation of crab meat from its exoskeleton or shell. The machine includes a number of specifically located rollers at a discharge end of an elongated belt type conveyor. Crab bodies and crab legs are placed on the belt conveyor which operates to move the bodies and legs in a prescribed direction toward the rollers. A first roller is situated above the discharge for the elongated conveyor while a second roller tangentially engages the first roller and is located downstream of the conveyor discharge. A space is thus provided between the second roller and conveyor discharge through which meat may fall. The crab parts moving on the conveyor are first engaged between the conveyor and first roller. These two members act as a gripping mechanism by which the crab parts are firmly held while being directed on downstream to engagement with the peripheral surface of the second roll.
    Type: Grant
    Filed: November 8, 1976
    Date of Patent: April 11, 1978
    Assignee: Applied Magnetics, Inc.
    Inventor: Walter L. Davis
  • Patent number: 4073041
    Abstract: An apparatus is described for automatically butchering crabs. The machine includes a conveyor for transporting successive crabs in an inverted condition past a series of spaced work stations. At a first work station the carapace is removed as the conveyor moves the crab past a carapace removing means. Side brushes at a second and third station rotate to remove the gills while jets of water are sprayed against the exposed bottom side to remove the viscera. The conveyor moves the crabs continuously along the prescribed path during this operation. Finally, a guillotine apparatus is positioned along the prescribed path at a fourth work station to successively sever the legs from the crab bodies. The eviscerated, legless bodies then drop into a receiving bin. The conveyor is controlled so as to move at a relatively slow rate while the crab carcasses move through each successive work station. The speed is then increased as the crabs move from one station to another.
    Type: Grant
    Filed: August 30, 1976
    Date of Patent: February 14, 1978
    Assignee: Applied Magnetics, Inc.
    Inventors: Walter L. Davis, Henry V. Svehaug