With Process Control System Patents (Class 330/1A)
  • Patent number: 4158162
    Abstract: A time-proportioning control system is disclosed for controlling an on-off solenoid valve of an earth-working machine, the system having a sensor responsive to an external reference for producing an error signal, an amplifier switch for switching on and off the on-off solenoid valve in response to the error signal and a capacitive feedback circuit connected from the output to the input of the amplifier switch for controlling the on and off times of the solenoid valve dependent upon the magnitude of the error signal.
    Type: Grant
    Filed: June 20, 1977
    Date of Patent: June 12, 1979
    Assignee: Honeywell Inc.
    Inventor: Royal R. Hawkins
  • Patent number: 4136307
    Abstract: A process controller for diameter control in drawing optical fibre preforms consists essentially of the parallel arrangement of two output amplifiers, one providing low gain at low .+-. input voltages, while the other has high gain at high .+-. input voltages and effectively zero gain at low .+-. input voltages.
    Type: Grant
    Filed: July 18, 1977
    Date of Patent: January 23, 1979
    Assignee: International Standard Electric Corporation
    Inventor: Brian J. Scott
  • Patent number: 4052677
    Abstract: The generator includes an input terminal, an output terminal, and three channels connected between the input and output terminals. The first channel contains a first amplifier and a first FET switch connected in series between the terminals. The second channel contains a second amplifier and a second FET switch connected in series between the terminals. The third channel contains an adjustable resistor and a third FET switch connected in series between the terminals. An adjustable bias signal positively offsets the output signal of the first amplifier and negatively offsets the output signal of the second amplifier to produce a signal deadband. When an applied input signal lies within the deadband, a signal from the resistor lies between the amplifier output signals, and a pair of comparators turn on the third FET and turn off the first and second FET's. This produces an output signal which follows the input signal with a gain determined by the resistor adjustment.
    Type: Grant
    Filed: September 29, 1976
    Date of Patent: October 4, 1977
    Assignee: Honeywell Inc.
    Inventor: James A. Hogan
  • Patent number: 4001703
    Abstract: An interface circuit for a transmission line between a remote transmitter and a central control room instrument includes an operational amplifier. The input of the operational amplifier is derived from the current drawn by the remote transmitter. The output signal of the operational amplifier is applied to control the operation of a transistor current controlling amplifier. The current controlled by the transistor amplifier is drawn from the same source as the current drawn by the transmitter. Because of a feedback connection from the transistor amplifier to the input of the operational amplifier, the output current from the transistor amplifier is a mirror image of current drawn by the transmitter. With that arrangement, both the power supply and the remote transmitter may be grounded without loss of accuracy or reliability.
    Type: Grant
    Filed: October 20, 1975
    Date of Patent: January 4, 1977
    Assignee: Honeywell Inc.
    Inventors: Glenn Saul, Philip W. Bur