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Clockwise Counterclockwise Stepper Motor Rotation Control using Combinatorial Logic

IP.com Disclosure Number: IPCOM000079926D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 55K

Publishing Venue

IBM

Related People

Mattson, GL: AUTHOR

Abstract

This stepper motor rotation control constitutes a simple, low cost and easily implemented approach to rotation direction control, and includes basically only two flip-flops 50 and 52 for controlling stepper motor 54.

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Clockwise Counterclockwise Stepper Motor Rotation Control using Combinatorial Logic

This stepper motor rotation control constitutes a simple, low cost and easily implemented approach to rotation direction control, and includes basically only two flip-flops 50 and 52 for controlling stepper motor 54.

The stepper motor 54 is diagramatically shown and includes four poles 54N, 54E, 54S and 54W which may be considered, respectively, north, east, south and west poles. The armature 54A may have four stable positions 1, 2, 3 and 4, which are obtained by selectively energizing pairs of poles, respectively, 54N and 54E, 54S and 54E, 54S and 54W, 54N and 54W, and 54N and 54E for one complete clockwise revolution.

Flip-flops 50 and 52 are connected through drivers 56 with stepper motor 54 in Fig. 1, to provide energization of the poles 54N, 54E, 54S and 54W in the proper sequence to obtain clockwise rotation of armature 54A. Input pulses are supplied on lead 58 applied as clock pulses to each of flip-flops 50 and 52, and the state of each of flip-flops 50 and 52 changes as follows: J K Q

(Before Pulse) (After Pulse)

0 0 0

0 1 0

1 0 1

1 1 Q.

TABLE I

Prior to the first pulse on line 58 (it is assumed that armature 54A is in position 1), J(NS) = W = 0 and K(NS) = E = 1: therefore, from Table I, signal N is 0 after the first pulse and J(EW) = N = 1 and K(EW) S = 0; therefore, signal E will be 1 after the first pulse.

A truth table for this operation is as follows: Position Outputs Required JK Levels

N S E W J(NS) K(NS) J(EW) K(EW)

1 1 0 1 0 - 1 - 0

2 0 1 1 0 0 - - 1

3 0 1 0 1 1 - 0 -

4 1 0 0 1 - 0 1 -

1 1 0 1 0 ( - don't

care - maybe 1 or 0)

J(NS) = W K(NS) = E J(EW) = N K(EW) = S. TABLE II

The outputs of the flip-flops 50 and 52 are shown in Fig. 2 and change state on the leading edge of the pulses applied to line 58, and each pulse represents a step of armature 54A. Armature 54A rotates in the clockwise direction.

Exclusive OR circuits 60 and 62 and an inverter 64 are connected as shown in Fig. 3 with flip-flops 50 and 52, in order to allow rotation of armature 54A in

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either direction, this being under the command of an X input on lead 66 connected as an input to exclusive OR circuit 62.

(Image Omitted)

In further explanation of Table III, the X signals in column (a) ind...