JPH01311894A - Driver for stepping motor - Google Patents

Abstract

PURPOSE:To prevent a second step pulse from lacking by detecting a variation in an input direction signal and resetting a step pulse interval detector in response to the variation. CONSTITUTION:When a stepping direction is altered and a step pulse interval is simultaneously varied, a variation in a direction signal is detected by a direction switch detector 8, and a step pulse interval detector 3 is reset. The control of a second pulse switching circuit 4 is released by the reset of the detector 3. A pulse generator 2 generates a second step pulse under the control of the circuit 4 subsequently to the first step pulse. Thus, the second step pulse does not lack.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a driving device for a stepping motor used in a flexible disk device or the like.

[Prior Art] FIG. 3 is a block diagram showing a stepping motor drive device of a conventional flexible disk device. In the figure, (1) is a step pulse signal input terminal, (2) is a pulse train generation circuit, and (3) is a step pulse signal input terminal that detects the signal interval of step pulse signals that are continuously input to the step pulse signal input terminal (1). A step pulse interval detection circuit that changes the output signal when the signal interval changes beyond a predetermined range (
4) is the second pulse switching circuit, (5) is the stepping motor drive circuit, (6) is the stepping motor, (7)
is a direction signal input terminal.

Next, the operation will be explained with reference to FIG. FIG. 4 is a time chart for explaining an example of this operation.
) shows the input step pulse train, (b) shows the input direction signal, (C) shows the internal step pulse train generated by the pulse train generation circuit (2), (11) shows the input step pulse signal, and (12) shows the internal step pulse train. The first step pulse, (13) is the internal second step pulse, (14) is the direction signal, and (15) is its switching point.

Now, when the step pulse signal (1) is continuously input through the step pulse signal input terminal (1), the pulse generation circuit (2) generates the first step pulse (12) in synchronization with the step pulse signal (11). ), then a predetermined reference time T. A second step pulse (13) is then generated and output to the output terminal in the direction determined by the direction signal (14) indicating the step direction input from the direction signal input terminal (7).

The step pulse interval detection circuit (3) detects the pulse interval of the input step pulse signal (11), and switches the second pulse switching circuit (4) according to the step pulse interval.
control. When the pulse interval of the input step pulse signal (11) is within a predetermined range Ts near the set value Ts, the second pulse switching circuit (4) is not controlled at all. The second step pulse (13) is generated at the reference timing, and if the pulse interval exceeds the predetermined range of the set value Ts and changes to Tsl, the pulse generation circuit (2)
The second step pulse (13) is generated at the timing □, and the longer interval Ts exceeds the predetermined range of the set value Ts.
, when the step pulse signal (11) is input, a two-step pulse (13) signal is generated at timing T2 (T<T, <T,).

At this time, the step pulse signal interval is significantly reduced (T
s2→Ts1) and the generation timing of the next first step pulse (12) before the second step pulse (13) (
Since T2≧Ts,), the second step pulse (13) may be missing, so it is necessary to reduce the step pulse signal interval through an intermediate step pulse signal interval Ts0, rather than reducing it significantly all at once.

Also, when the stepping direction is changed and the step pulse signal interval is changed at the same time.

The step pulse signal interval is greatly reduced at once (Ts
2→Ts1), the second step pulse (13') is not generated.

The stepping motor drive circuit (5) amplifies the output of the pulse train generation circuit (2) and generates a direction signal (14).
The stepping motor (6) is driven in the direction determined by.

[Problems to be Solved by the Invention] The conventional stepping motor drive device is configured as described above, and if the step pulse signal interval is significantly reduced at once, the second step pulse may be missing. It is necessary to reduce the pulse signal interval through intermediate step pulse signal intervals without reducing the pulse signal interval by a large amount b5 all at once. However, when changing the stepping direction, that is, when reversing the stepping motor (6),
At the same time, there was a problem in that although it was required to significantly reduce the speed, this was not possible.

This invention was made to solve the above-mentioned problems, and provides a stepping motor drive that can operate the stepping motor correctly even if the step pulse interval is significantly reduced at the same time as the stepping direction is changed. The purpose is to obtain equipment.

[Means for Solving the Problems] A stepping motor drive device according to the present invention detects a change in a muca direction signal indicating a step direction,
A derailleur eye switching detection circuit is provided which resets the step pulse interval detection circuit accordingly.

[Function] In the stepping motor drive device of the present invention, when the direction change detection circuit detects a change in the direction signal due to switching of the stepping direction, the stepping motor drive device changes the previous step pulse signal interval set in the step pulse interval detection circuit. is reset, and the first second step pulse after switching is generated at a predetermined reference timing,
Thereafter, the second step pulse is generated at a timing corresponding to the newly detected step pulse signal interval.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram showing one embodiment of the present invention, and FIG. 2 is a time chart for explaining the operation.

In the figure, (1) is a step pulse signal input terminal, (
2) is a pulse train generation circuit, (3) is a step pulse interval detection circuit, (4) is a second pulse switching circuit, (5) is a stepping motor drive circuit, (6) is a stepping motor, and (7) is a direction signal input terminal. , (8) is a direction switching detection circuit that detects a change in the input direction signal and resets the step pulse interval detection circuit (3) accordingly, (11) is the input step pulse signal, and (12) is the internal first Step pulse, (13
) is the internal second step pulse, (14) is the direction signal, and (15) is its switching point. In the figure, the same reference numerals as in FIGS. 3 and 4 indicate the same or corresponding parts.

Next, the operation will be explained. The operation when the stepping direction is not changed is the same as that of the conventional example shown in FIGS. 3 and 4, so the explanation will be omitted.

When the stepping direction is changed and the step pulse signal interval is changed from Ts to Ts, the direction change detection circuit (8) detects the direction signal (1).
4) is detected and the step pulse interval detection circuit (3) is reset. By resetting the step pulse interval detection circuit (3), the control of the second pulse switching circuit (4) is released, and the pulse generation circuit (2) generates the first step pulse (12) in synchronization with the step pulse signal (11). Then, after a predetermined reference time T0, a second step pulse (13) is generated, and then a new step pulse signal interval Ts is generated by the step pulse interval detection circuit (
3), the second pulse switching circuit (4) is controlled according to the step pulse interval, and the second step pulse (13) is generated from the pulse generating circuit (2) at a new timing T□. In this way, even if the step pulse signal interval decreases significantly from Ts2 to Ts□, the second
The step pulse generation timing is from T2 to T. Go to T
Therefore, by selecting the reference time T0 to be smaller than the shortest step pulse signal interval Ts□, the second
No step pulses are missed.

[Effects of the Invention] As described above, according to the present invention, since a direction switching detection circuit is provided that resets the step pulse interval detection circuit according to a change in the direction signal, the step pulse interval can be adjusted simultaneously with a change in the stepping direction. Even if this is significantly reduced, there is an effect that the stepping motor can be operated correctly without causing disturbances or abnormal noises in the stepping motor due to the omission of the second step pulse.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is a time chart for explaining its operation, Figure 3 is a block diagram showing a conventional stepping motor drive device, and Figure 4 is a block diagram showing a conventional stepping motor drive device.
The figure is a time chart for explaining its operation. In the figure, (1) is a step pulse signal input terminal, (
2) is a pulse train generation circuit, (3) is a step pulse interval detection circuit, (4) is a second pulse switching circuit, (5) is a stepping motor drive circuit, (6) is a stepping motor, and (7) is a direction signal input terminal. , (8) is a direction switching detection circuit. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A pulse train generation circuit generates a pulse train for two steps of feed with one input step pulse signal and applies it to the stepping motor drive circuit, and a pulse train generation circuit detects the signal interval of the step pulse signal that is continuously input, and the signal interval is A step pulse interval detection circuit whose output signal changes when the output signal changes beyond a predetermined range, and a second pulse switching circuit which switches the generation timing of the second step of the pulse train generation circuit according to the change in the output of the step pulse interval detection circuit. In the stepping motor drive device equipped with the
A stepping motor drive device comprising a direction switching detection circuit that resets the step pulse interval detection circuit accordingly.