David Wayne Stringfellow

US Patent:

56636164, Sep 2, 1997

Filed:

Aug 17, 1995

Appl. No.:

8/516247

Inventors:

David Wayne Stringfellow - Kokomo IN
Abhijeet V. Chavan - Ann Arbor MI

Assignee:

Delco Electronics Corporation

International Classification:

H02K 2300

US Classification:

318254

Abstract:

A noise tolerant motor position monitoring circuit having a digital filter section receives and filters noisy hall effect sensor inputs for use in determining rotational motor position. The motor position monitoring circuit exchanges information and instructions with a microprocessor which utilizes the motor position information to calculate motor distance traveled, motor speed, etc. The hall effect sensor signals are noisy due to the particular environment in which the sensed motor is placed, such as in industrial process and automotive applications. Each monitored segment of rotation corresponds to the motor rotational switching sequence of a motor driver circuit, a digital counter generates a running total rotational count and increments or decrements the total count depending upon the direction of motor rotation. A programmable digital filter time constant is generated and, via state machine operation, a hall sensor signal duration range is implemented for differentiating valid motor rotation signals from spurious noise signals. The desired operating range is programmably altered via the microprocessor and programmable digital filter time constant to allow the motor position monitoring circuit to operate for a broad range of motors having divergent characteristics.

US Patent:

51441594, Sep 1, 1992

Filed:

Nov 26, 1990

Appl. No.:

7/617713

Inventors:

Anthony E. Frisch - Kokomo IN
David W. Stringfellow - Kokomo IN

Assignee:

Delco Electronics Corporation - Kokomo IN

International Classification:

G11C 1100

US Classification:

3072723

Abstract:

An output of a power-on-reset (POR) circuit is coupled to another circuit which needs to have the logic states thereof reset during each time a power supply used to power same is switched on. The POR circuit includes a first input circuit for generating an output signal that tracks the power supply output voltage Vdd approximately a first predetermined threshold below Vdd, as Vdd ramps up and further includes a second input circuit which generates an output signal which tracks approximately a second predetermined threshold above a second fixed voltage level, e. g. , ground. The POR circuit further includes a comparator which compares the output signals from the first and second input circuits and switches an output signal thereof from a first to a second logic state once the input circuit output signals cross each other. A buffer is typically coupled to the output of the comparator to limit loading on same so as not to affect the comparator switching point.

US Patent:

55743463, Nov 12, 1996

Filed:

May 15, 1995

Appl. No.:

8/441108

Inventors:

Abhijeet V. Chavan - Ann Arbor MI
David W. Stringfellow - Kokomo IN
Sanmukh M. Patel - Indianapolis IN

Assignee:

Delco Electronics Corporation - Kokomo IN

International Classification:

H02H 726

US Classification:

318434

Abstract:

A fault detection circuit monitors voltage drops associated with phase windings of a brushed or brushless reversible multi-phase motor and compares them with reference voltages to determine if the motor is out of normal operating range parameters and if a valid fault condition exists. The fault detection circuit-is included in a motor control circuit and is configurable for use with a wide variety of motors having a broad range of load characteristics. The fault detection circuit includes a programmable clock generator which generates time delays for masking faults detected during start-up and during motor phase sequencing. The fault detection circuit thereby avoids transient and spurious faults and prevents the unnecessary termination of motor operation. The length of the mask time delay required for effective fault detection operation depends on the load characteristics of the selected motor. The parameters defining the mask time delay are selected to match the time delay to the characteristics of the motor.

US Patent:

56641672, Sep 2, 1997

Filed:

Mar 27, 1995

Appl. No.:

8/411370

Inventors:

James Kyle Pickett - Austin TX
David Wayne Stringfellow - Kokomo IN

Assignee:

Delco Electronics Corporation - Kokomo IN

International Classification:

G06F 114
G06F 944

US Classification:

395557

Abstract:

A programmable apparatus and method are provided for processing multiple routines so as to realize different timing resolutions. The apparatus includes a programmable timer device equipped with instruction memory for storing programmed instructions and programmable memory for storing a plurality of program counter entries, each dedicated to a corresponding routine. A plurality of program loops are provided, each of which includes a selected number of program counter entries. One entry from each of the program loops is sequentially selected and a corresponding instruction is executed. The number of entries dedicated to each program loop, or subloop, is selected so that different routines may realize different timing resolutions. Furthermore, program subloop entries could be repeated one or more times within a given loop to further improve (make finer) the timing resolution.