Alan W Wilkerson DeceasedCedarburg, WI

4914383, Apr 3, 1990

Jul 26, 1989

7/386028

Alan W. Wilkerson - Thiensville WI

G01R 122
G01R 3300

324127

A non-contact ammeter for measuring direct current in a conductor has a core capable of carrying a magnetic flux. The core surrounds the conductor so that the latter serves as a primary winding for the core. A second winding on the core is inductively coupled to the conductor. A current indicator is connected to the second winding. A control establishes the voltage on the second winding and flux changes in the core to avoid or limit saturation of the core. The control may be responsive to the flux condition of the core.

5629598, May 13, 1997

Jun 13, 1995

8/489944

Alan W. Wilkerson - Cedarburg WI

H02P 541

318808

An apparatus and method controls the speed of an AC induction motor by varying the frequency and current to the motor from an inverter power supply. A Counter EMF regulator receives a reference signal corresponding to the desired speed, and a signal proportional to CEMF for feedback. The output of the CEMF regulator is provided to the power supply to control the current to the motor. The CEMF feedback signal is also utilized to vary the output frequency of the power supply in accordance with the magnitude of the CEMF. This maintains the magnetizing component of stator winding current at a constant value for all operating frequencies of the motor. A signal corresponding to the load current component of the stator winding adds to the speed reference signal to the CEMF regulator to increase CEMF and frequency with increasing load, thereby to compensate for increased slip and maintain constant speed. The voltage on a DC bus in the inverter power supply is compared to a reference signal, the magnitude of which corresponds to the voltage on the bus when the motor is operating at synchronous speed. If the bus voltage is less than the reference voltage, the motor is in the motoring condition and the frequency of the power supply is determined by the CEMF.

4020287, Apr 26, 1977

Mar 3, 1975

5/554506

Alan W. Wilkerson - Thiensville WI

Allen-Bradley Company - Milwaukee WI

H04M 1100

179 2A

Electrical phenomena from electric motor drive circuitry is transmitted through telephone couplers, telephones, and telephone lines to provide signal data to a service technician remote from the circuitry for ascertaining the operative condition of the motor drive circuitry.

3946242, Mar 23, 1976

Mar 3, 1975

5/554972

Alan W. Wilkerson - Thiensville WI

F03D 900
H02J 340

307 45

A conversion means converts the energy available from a source, such as the wind or sun, into a corresponding amount of d. c. electrical power. A switching circuit, typically a thyristor bridge, is connected between the conversion means and an a. c. load and across a. c. power mains energizing the load. The switching circuit is operable to periodically connect the conversion means to the a. c. load in a power supplying manner. The a. c. mains impart suitable voltage and frequency characteristics to the electrical power so supplied. In the event the supplied power exceeds the power required by the a. c. load, the difference is taken by the a. c. power mains.

5283726, Feb 1, 1994

Dec 20, 1991

7/810961

Alan W. Wilkerson - Cedarburg WI

H02M 112

363 41

A controller for controlling currents in an AC line connected to the controller is capable of causing the controlled current to assume any pre-determined magnitude and wave form. The pre-determined AC magnitude and wave form need not be of the same frequency or wave form existing at AC power lines connected to the controller. The controller uses the voltage at the AC power lines and an additional DC voltage as two sources of power to control the current in an inductor connected in series with the AC lines. A plurality of electronic switches are arranged so that at any instant in time, closing of appropriate switches will apply either the line voltage, or the sum of the line voltage and the DC voltage, or the difference between the line voltage and the DC voltage to the inductor. This causes the current of the inductor to increase or decrease at a rate determined by the net applied voltage. Because of the two sources of power, either a positive or negative voltage is available at any time for connection to the inductor.

4027220, May 31, 1977

May 5, 1975

5/574550

Alan W. Wilkerson - Thiensville WI

Allen-Bradley Company - Milwaukee WI

H02P 314

318376

The field circuit of a regenerative direct current motor control provides rapid reversal of motor field current by discharging the inductive energy of the winding back to an alternating current power supply. This is accomplished by firing the thyristors means in the field circuit late in the half cycles of alternating current by means of an improved firing circuit.

4074194, Feb 14, 1978

Feb 28, 1977

5/773070

Alan W. Wilkerson - Thiensville WI

G01R 700

324142

A watt meter circuit capable of providing an electrical signal indicative of power includes a signal forming means for providing a pair of signals proportional to current. The signals are equal to each other in magnitude but opposite in polarity and are provided in parallel through a switch to filter which provides the electrical power signal. The switch is operated by a signal generating means which generates a triangular wave form. The voltage to the watt meter is compared with the triangular wave form to vary the duty cycle of the switch and the magnitude and polarity of the output signal in accordance with the algebraic product of voltage and current.

6124697, Sep 26, 2000

Aug 18, 1998

9/135766

Alan W. Wilkerson - Cedarburg WI

H02P 528

318798

A drive for controlling the speed of an AC induction motor from an inverter. The inverter applies a voltage to the stator winding of the motor in accordance with the magnitude of a first input signal. The inverter causes the voltage to be applied at a frequency determined by the magnitude of a second input signal to the inverter. The drive includes motor speed sensor and a motor speed reference signal source coupled to a speed regulating amplifier. A slip detector determines the slip of the motor from the speed of the rotor and the energization frequency of the stator winding. A slip regulating amplifier receives the output signal from the speed regulating amplifier and the slip signal and provides an output to a summing amplifier. The summing amplifier also receives a motor speed signal and provides an output. The output comprises the second input signal to the inverter.