Patents by Inventor Glenn Mayfield

Glenn Mayfield 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: 4417198
    Abstract: Transducers of the average responding RMS indicating type are disclosed that are particularly useful for monitoring currents and voltages in a power distribution network. The transducer includes transformer, inductively compensated voltage divider, active filter and output amplifier circuits electrically connected to provide a transducer having excellent long term transducer stability so that the transducer requires no calibration, and a highly accurate readout over a wide temperature range.
    Type: Grant
    Filed: August 31, 1981
    Date of Patent: November 22, 1983
    Assignee: Duncan Electric Company, Inc.
    Inventor: Glenn A. Mayfield
  • Patent number: 4055804
    Abstract: A watt/watthour meter of improved accuracy and relatively lower cost than a conventionally designed device with similar specifications. A current proportional to instantaneous power is obtained from a current-voltage multiplier circuit and is maintained as a current signal through amplifying and filtering, and through the watt output load. The watt output amplifier is a current input, current output amplifier which simultaneously functions as an active ripple filter. It directly couples the input signal to the inverting input and capacitively couples the input ripple to the non-inverting input of the amplifier's op-amp. The output load, which is externally connected between the inverting input and the output of the op-amp, does not have a common with the internal ground and effectively floats with the ripple.
    Type: Grant
    Filed: May 14, 1976
    Date of Patent: October 25, 1977
    Inventor: Glenn A. Mayfield
  • Patent number: 3976942
    Abstract: A watt/watthour meter of improved accuracy and relatively lower cost than a conventionally designed device with similar specifications. A current proportional to instantaneous power is obtained from a current-voltage multiplier circuit and is maintained as a current signal through amplifying and filtering, through the watt output load and through integrating in the watthour section. The multiplier uses a chopper modulator which provides two identical output current sources both floating with respect to ground so that one may be connected to the watt output amplifier and one to the watthour integrator. The signal from the power line which is proportional to the voltage modulates the signal which is proportional to the power line current by alternatively switching the modulated current between the two source outputs and by maintaining zero average input current flow from the modulated current signal through use of dc blocking capacitors.
    Type: Grant
    Filed: December 13, 1974
    Date of Patent: August 24, 1976
    Assignee: Esterline Corporation
    Inventor: Glenn A. Mayfield
  • Patent number: 3975682
    Abstract: A watt/watthour meter of improved accuracy and relatively lower cost than a conventionally designed device with smilar specifications. A current proportional to instantaneous power is obtained from a current-voltage multiplier circuit and is maintained as a current signal through amplifying and filtering and through the watt output load and through integrating in the watthour section. The watthour integrator uses a charge compensation integrator circuit to integrate one of the watt signal currents and it can integrate in either direction corresponding to power in or power out. This can be accomplished because circuitry is disclosed to provide a current pulse having a precise magnitude and in either of two alternative, opposite current flow directions.
    Type: Grant
    Filed: December 13, 1974
    Date of Patent: August 17, 1976
    Assignee: Esterline Corporation
    Inventor: Glenn A. Mayfield
  • Patent number: 3971979
    Abstract: A circuit for providing an output direct current which is a linearly proportional analog of the average and the effective magnitude of a sinusoidal input voltage or current. A transformer couples the sinusoid to a rectifier which applies a rectified sinusoid to a filtered current mirror circuit of low power requirements in order to provide a ripple free, high impedance current source output. The current mirror circuit is imbalanced in order to provide a non-linear characteristic which compensates for the transformer-rectifier non-linearity. The current mirror circuit also has an RC feedback network with sufficient feedback and gain to obtain an active, low pass filter characteristic. Component values are selected to give a sharp cutoff, active filter just below the ripple frequency to give efficient ripple elimination yet permit a rapid response time.
    Type: Grant
    Filed: October 10, 1974
    Date of Patent: July 27, 1976
    Assignee: Esterline Corporation
    Inventor: Glenn A. Mayfield