Browse Prior Art Database

Electronic Motor Control for Fan

IP.com Disclosure Number: IPCOM000105645D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Bernhardt, HG: AUTHOR [+2]

Abstract

A fan for cooling purposes has electronic control means which flexibly adapt the motor to different temperature/speed characteristics.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 62% of the total text.

Electronic Motor Control for Fan

      A fan for cooling purposes has electronic control means which
flexibly adapt the motor to different temperature/speed
characteristics.

      Different control characteristics and operating points are
obtainable by microcode.  Changes or subsequent adaptations are
carried out by new software rather than by exchanging the existing
hardware.  The circuit employed is such that the operation of the
motor is independent of variations in the supply voltage, so that the
above characteristics are accurately observed.  Errors are
automatically detected by comparing the desired and the actual speed
values.

      The fan is equipped with a logic which is
memory/microcode-controlled by a processor control card with a
microprocessor.  The design of the fan motor is such that its full
air supply is available even at the minimum supply voltage.  If the
actual supply voltage is higher, the motor is controlled by pulse
width modulation PWM.

      Different temperature/speed characteristics are stored as tem
perature/speed tables in the memory of the processor control card and
may be flexibly loaded.

      The temperature value transmitted by a sensor triggers a
desired speed value which is used as a motor control signal by PWM.
The actual speed of the motor is digitally indicated.  A warning
signal is emitted when the motor speed drops by a defined percentage.

      A standard fan of the kind described may be used for...