Browse Prior Art Database

Sensorless Spindle Motor Control

IP.com Disclosure Number: IPCOM000101856D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 4 page(s) / 114K

Publishing Venue

IBM

Related People

Erickson, KJ: AUTHOR [+2]

Abstract

This article describes two alternative methods to perform two of the functions of a typical sensorless spindle control system.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Sensorless Spindle Motor Control

       This article describes two alternative methods to perform
two of the functions of a typical sensorless spindle control system.

      The first method, called a Switched Filter, is intended for use
in sensorless spindle control designs that require two separate
low-pass back-EMF filters, one filter is used for starting the motor,
and the other filter is tuned for optimum motor operation at the
fixed operating speed.  This method can be used to reduce the amount
of circuity, the complexity of the design, and the cost required to
implement the typical dual low-pass filter technique.

      The second method, called a Pseudo Centertap, is intended for
use in sensorless spindle control designs that utilize motors that
are made without wiring the centertap out of the motor (in the case
of a wye- wound motor) or do not have a physical centertap at all (in
the case of a delta-wound motor).  This method can be used to reduce
the cost of a wye-wound motor used in the system by eliminating the
need to provide a physical centertap.  Also, this method is essential
for controlling a delta-wound sensorless spindle motor, because it
does not have a physical centertap.

      Fig. 1 shows a block diagram of the typical functions required
to control a sensorless spindle motor system.  The microprocessor is
used to perform a number of simple functions to either start or stop
the motor while the operation at the fixed operating speed is
automatic and does not require any microprocessor activity.

      In this diagram the microprocessor is shown to be in control of
both the motor drive circuits and the brake circuits, which are used
to either enable and sequence the drive to the motor, or stop the
motor.  It is also shown to be in control of two multiplexers, the
first of which is used to select between the forced "Hall" signals
...