JPS6011557B2 - Step motor driving method and its driving circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a driving method and circuit for controlling the rotational direction of a step motor, that is, clockwise or counterclockwise.

Conventionally, a drive circuit for a four-phase step motor has had a circuit configuration as shown in FIG. 1 for clockwise rotation.

That is, a clock pulse as shown in FIG. 2a is input to the input terminal 11, and a control signal for the number of clock pulses is input to the input terminal 12. Then, the output of the AND circuit 13 is applied as a clock signal to the two flip-flop circuits 14 and 15, and the respective flip-flop circuits 14 and 15 as shown in FIG.
Q and Q outputs of A phase, B phase, C phase and D
It is output as a phase output. These outputs are rearranged in the order of A, C, 8, and D so that the pulses are phase-shifted by 90 degrees, and are sequentially supplied counterclockwise through the solenoid buffers of each phase of the step motor. Then, it rotates clockwise by 15 degrees per step, and stops at a predetermined layer depending on the number of clock pulses. With this follow-up method, it is impossible to change direction from clockwise to counterclockwise. Therefore, if you want to control counterclockwise as well, a separate external control circuit is required, and this separate The external control circuit had the disadvantage that direction changing operations were troublesome and expensive.

The present invention has been made to solve these conventional drawbacks, and uses a register to input a certain initial value to the output port of this register corresponding to each phase.
When shifted in one direction, it rotates in one direction, and when it rotates in the opposite direction, one phase is replaced with another, so that the relationship between each phase of the step motor and each step position is in the opposite direction from the forward direction. The present invention relates to a driving method and a circuit thereof in which a shift is made to a driving method.

That is, in the circuit shown in FIG. 1, the relationship between each phase (A, B, C, and D phase) and the step position (1, 0, m, W) is as shown in FIG. It will look like Table 1. Table 1 If this is rearranged so that the pulses are phase-shifted by 90 degrees, it can be rewritten as shown in Table 2.

Table 2 It can be seen from Table 2 that when trying to rotate one step clockwise, for example, the initial position is "0011".
That is, it is sufficient to set "3" in the register and perform one left shift.

When this left shift is repeated one after another, the motor rotates clockwise. Conversely, if you want to rotate one step counterclockwise, set the same initial position as "0011" or "3".
'' in the register, and as shown in parentheses in Table 2, for example, phase A and one phase B are exchanged by appropriate means, and a single left shift is performed. When this left shift is reversed one after another, the motor rotates counterclockwise. From the above,
The direction of rotation can be controlled with just a register and an inversion signal. An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, the step motor 20 will be described as an example of a four-pole motor that rotates 24 steps per rotation and 15 degrees per step. 21 is a register such as an accumulator, and since the step motor 20 has four phases, it has a storage capacity that is a multiple of 4 bits.

22 is a shift control circuit that controls the shift direction of the register 21;

0, 1, 2, and 3 are output ports, and among these, two output ports 0 and one 2 have direct drivers 23 and 25.
is connected to the other two output ports 1 and 3 via circuits 27 and 28 that exchange outputs with each other.
6 is connected.

The exchange circuits 27, 28 each consist of two AND circuits 29, 30, 31, 32 and one OR circuit 33, 34, and each inverting signal terminal 35 is directly connected to one AND circuit 29, 32. and the other AND circuit 30,
31 via an inverter 36. That is, output port 1 is connected to one input side of AND circuits 29 and 31, and output port 3 is connected to one input side of AND circuit 31.
0, 32, and the inverted signal terminal 35
are connected to the AND circuits 29, 32, the inverter 36 is connected to the AND circuits 30, 31, and the output sides of the AND circuits 29, 30 are connected to the driver 24 via the OR circuit 33, respectively. The output sides of 32 are each connected to the driver 26 via an OR circuit 34. The drivers 23, 24, 25, and 26 are connected to four-pole step motors via buffers (not shown), respectively.
The D-phase, A-phase, C-phase, and B-phase of 20 are connected in this order, respectively. The reason why the connection order at this time is D, A, C, B instead of A, B, C, D is because each pulse is rearranged so that it is sequentially output to the adjacent phase with a 90 degree phase shift. It depends on what happened. Next, the operation of the present invention will be explained.

First, the register 21 is set to, for example, "0011" or "3" as an initial value regardless of whether it is forward or backward.

Then, output boats 3, 2, 1, and ``0011'' are read out. Here, since the inversion signal terminal 35 is "1" when rotating clockwise, this "1" is input to one input side of the AND circuits 29, 32 connected to the output ports -, 3, and the exchange circuit From 27 and 28, output boat 1,
The signal of 3 is sent out as it is, and the driver 26, 25,
The outputs of 24 and 23 become ``0011'' like step ``1'' in Figure 5a, and this signal energizes the A and D phase solenoids of the B, C, A, and D phases of the step motor 20. and enters the set state. After time t in FIG. 6 has elapsed, the register 21 is shifted to the left.

Then, the outputs of output boats 3, 2, 1, and 0 become step “
This output is sent as is to the drivers 26, 25, 24, and 23, and the C and A phases are excited. Thereafter, when the left shift is performed three times every t time, the steps change to "m", "W", and "1", and the step returns to the original state by turning 1/6. Next, when rotating counterclockwise, when the OJ signal is sent to the inverted signal terminal 35, output ports 3 and 2
, 1, 0, the A phase and B phase are switched to switching circuits 27, 2.
8, as in step ``W'' in Figure 5b.
001", and if you shift left in this state, step "
W”, “m”, “0”, “1” rW”...
Rotates in the direction of the arrowhead.

Its action is almost the same as clockwise. Note that when "1" and "0" are alternately input to the inversion signal terminal 35 at regular intervals, the step motor 20 rotates in forward and reverse directions alternately.

For example, it becomes easy to perform n rotations in the forward direction and then m rotations in the reverse direction. In the above embodiment, the register consisting of the accumulator has a 4-bit capacity, but it may also have a capacity of ■ bits (n=1, 2, . . . ).
The same initial value may be set for each of the lower four bits.

In addition, the step motor is not limited to 4-phase, but 4n-phase (n=1
, 2,...). Since the present invention employs the method and circuit as described above, the direction can be easily changed between clockwise and counterclockwise, and its concrete structure is only a register and a simple logic circuit as a switching circuit, so it is easy to implement. It can be provided easily and inexpensively.

Particularly, when used in devices using a step motor, such as a printer equipped with a tractor feed bag hawk, it has an extremely excellent effect.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional step motor drive circuit.
Figure 2 is a waveform diagram of each part, Figure 3 is a block diagram for realizing the driving method according to the present invention, Figure 4 is a flowchart, and Figures 5a and b are registers for forward rotation and reverse rotation. An explanatory diagram of the output boat, FIGS. 6a, b, c, and d are output waveform diagrams of each phase. 11... Clock pulse input terminal, 12...
・Pulse number control signal input terminal, 13...AND gate, 14, 15...Flip-flop circuit, 20...Step motor, 21...Register, 22...
...Shift control circuit, 0,1,2,3...Output port, 23,24,25,26...Driver, 27,2
8... Exchange circuit, 29, 30, 31, 32...
...AND circuit, 33, 34...OR circuit, 35...inverted signal terminal, 36...inverter. Figure 6 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 4n (n
is a positive integer), set the initial value in the bit register, read the pulse output for each bit of this register in parallel to the output port, and when rotating in the forward direction, read the output port sequentially from one side and add it to each phase. When rotating in reverse, one phase of the output port is exchanged with another phase other than this phase, and one phase is read out sequentially from the other, and each phase is added to drive the step motor in such a way that the direction of rotation is reversed. Method. 2. A register having a storage capacity that is a multiple of the number of phases of a step motor that sequentially outputs pulses shifted in phase by 90 degrees, a control circuit that shifts the register for each step rotation of the step motor, and a control circuit that is coupled to the register and that controls the number of steps of the step motor. The number of output ports is the same as the number of phases, and there is an output port for reading the output of each bit of the register in parallel, and an output port that is connected to one output port and one other output port when rotating in the opposite direction. an exchange circuit for exchanging the output of one phase with another phase;
A step motor drive circuit comprising: a driver coupled to the remaining output ports of the output ports and the exchange circuit for exciting a solenoid of the step motor. 3 In claim 2, the switching circuit is
A certain output port and one other output port are coupled to separate AND circuits, and an inverted signal terminal is directly connected to one of these AND circuits, and an inverted signal terminal is connected to the other through an inverter. This is a step motor drive circuit in which an OR circuit is connected to the output side of these AND circuits, and this OR circuit is connected to a driver.