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Deceleration Circuit for DC Servo Motor

IP.com Disclosure Number: IPCOM000099357D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 4 page(s) / 91K

Publishing Venue

IBM

Related People

Matsukawa, T: AUTHOR [+2]

Abstract

Disclosed is a deceleration circuit for a DC servo motor with Pulse- Width-Modulation control.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 75% of the total text.

Deceleration Circuit for DC Servo Motor

       Disclosed is a deceleration circuit for a DC servo motor
with Pulse- Width-Modulation control.

      Prior Pulse-Width-Modulation DC Servo Motor Control circuits
consist of the closed loop with DC motor, Rotary Encoder and
Pulse-Width-Modulation logic, as shown in Fig. 1. This circuit is
useful for fixed speed control.  The way to decelerate with the prior
circuit is to reverse-drive under the observation of the speed with
software.  The prior deceleration circuit has the following defects:

      1. The observation of speed imposes a big burden on software.

      2. Speed can easily become unstable because the closed loop
including software has a time delay.

      3. There is the possibility that the software's delay causes
the reverse rotation of motor.

      In this article, a deceleration circuit is added to the prior
Pulse-Width-Modulation circuit to solve these defects, and it enables
accurate control of the speed.

      The deceleration circuit is inserted between the Control Logic
and Drive Circuit in the prior circuit, as shown in Fig. 2.  The
deceleration circuit includes three functional blocks shown in Fig. 3
and the operation of the three blocks is as follows:

      1. Over Speed Detect Block includes two Exclusive-ORs 4 and 7,
and D-Flip-Flop 5 observes Encoder Pulse and Motor Control signals
and detects the over speed when the motor has not been driven during
the period o...