Dee R Walker

US Patent:

20020093306, Jul 18, 2002

Filed:

Jan 12, 2001

Appl. No.:

09/760276

Inventors:

Steven Johnson - Hartland WI, US
Kip Larson - Rapid City SD, US
Dee Walker - Rapid City SD, US

International Classification:

H02P001/26
H02P001/42
H02H005/04
H02P005/28
H02H007/08
H02P007/36

US Classification:

318/782000

Abstract:

A method and apparatus for controlling an electric motor pump. The method includes the acts of providing an AC power signal having a positive half cycle and a negative half cycle, measuring the voltage of the AC power signal and generating a first two-state output signal that is in a logic high state when the measured voltage is on the positive half cycle and that is in a logic low state when the measured voltage is on the negative half cycle, and measuring the current of the AC power signal and generating a second two-state output signal that is in logic high state when the measured current is on the positive half cycle and that is in a logic low state when the measured current is on the negative half cycle. The method also includes determining a time difference between the first and second two-state output signals, calculating a phase difference based on the time difference, comparing the phase difference to a predetermined threshold value, opening a switch if the determined phase difference is equal to or greater that the predetermined threshold value, and, after the switch is opened, closing the switch after a predetermined amount of time has elapsed. The invention may be implemented in an apparatus that includes a voltage filter capable of being coupled to an AC power source and of generating a first two-state output signal, a current filter capable of being a coupled to an AC power source and of generating a second two-state output signal, a power supply circuit capable of producing a DC power signal, a programmable device coupled to the voltage filter, the current filter, and the power supply circuit and operable to produce a control signal based on the time difference between the first and second two-state output signals, and a switch coupled to the programmable device and operable to open in response to the control signal.

US Patent:

20070103828, May 10, 2007

Filed:

Nov 8, 2005

Appl. No.:

11/268830

Inventors:

Kip Larson - Rapid City SD, US
Dee Walker - Rapid City SD, US

Assignee:

SymCom, Inc. - Wilmington DE

International Classification:

H02H 3/24

US Classification:

361088000

Abstract:

Systems and methods are disclosed for detecting a protection device operation. The disclosed systems and methods may include detecting a voltage across a protection device. The voltage may be produced when the protection device operates from a closed state to an opened state. Furthermore, the disclosed systems and methods may include latching, in response to the detected voltage, the indication that the protection device operated from the closed state to the opened state. Moreover, the disclosed systems and methods may include transmitting, in response to the detected voltage, an indication that the protection device operated from a closed state to an opened state.