JPS6347078B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a five-phase pulse motor with a pentagon drive system in which the current flowing through a plurality of windings that are excitation phases is always a constant current. This relates to the drive method.

Figures 1 to 3 idealize and explain the pentagon drive system of a five-phase pulse motor. FIG. 2 is a time chart showing the waveform of the winding current, and FIG. 3 is a time chart showing the waveform of the excitation signal of the transistor.

In Fig. 1, W1 to W5 are windings, Tr
1H to Tr5H and Tr1L to Tr5L
denotes a transistor, and A to E denote connection points of windings, respectively. Note that transistors marked with a circle indicate that they are in an on state, and transistors that are not marked with a circle indicate that they are in an off state. The windings W1 to W5 are connected to form a ring, and each node A, B, C, D, E is assigned a pair of transistors in a one-to-one correspondence. That is, transistors Tr1H and Tr1L are connected to node A, transistors Tr2H and Tr2L are connected to node B, transistors Tr3H and Tr3L are connected to node C, and transistors Tr3H and Tr3L are connected to node D.
Transistors Tr4H and Tr4L are assigned to the transistors Tr4H and Tr4L, and transistors Tr5H and Tr5L are assigned to the node E, and each node is connected to the midpoint of the corresponding pair of transistors. Transistor Tr1
The emitters of transistors H to Tr5H are connected to the power supply VCC, and the emitters of transistors Tr1L to Tr5L are grounded. Although not shown, each transistor Tr1H, Tr2H, Tr3H, Tr4H, Tr
There is a flyback between the emitter and collector of 5H.
A diode is provided, as well as each transistor
Flyback diodes are also provided between the emitters and collectors of Tr1L, Tr2L, Tr3L, Tr4L, and Tr5L.

In FIG. 1A, transistor Tr1L is on, transistors Tr2H and Tr3H are on,
Transistor Tr4L is on, transistor Tr5
H is on and the other transistors are off. Under such on/off states of the transistor, current flows in the positive direction (clockwise) in the winding W1, no current flows in the winding W2, and current flows in the negative direction in the winding W3. Current flows in the positive direction through the winding W4, and current flows in the negative direction through the winding W5.

When a certain period of time has elapsed since the state shown in FIG. 1A is reached, the transistor Tr3H is turned off, and the transistor Tr3L is turned off. Then, the state shown in FIG.
maintains the original current, but current begins to flow in the negative direction through winding W2, and the current in winding W3 is turned off.

When a certain period of time has elapsed since the state shown in FIG. 1B is reached, the transistor Tr4H is turned on and the transistor Tr4L is turned off. Then,
Windings W1, W2, and W5 retain their original current, but
Current begins to flow in the winding W3 in the positive direction, and the current in the winding W4 is turned off. This state is shown in FIG. 1C.

When a certain period of time has elapsed since the state shown in FIG. 1C is reached, the transistor Tr5H is turned on and the transistor Tr5L is turned off. Then,
Windings W1, W2, and W3 retain their original current, but
Current begins to flow in the winding W4 in the negative direction, and the current in the winding W5 is turned off. This state is shown in FIG. 1D.

FIG. 2 is a time chart showing the waveform of the winding current, and FIG. 3 is a time chart showing the waveform of the excitation signal to the transistor.

A, B, C, and D in Figures 2 and 3 correspond to A, B, C, and D in Figure 1, and in Figure 3, the transistor is on when H is on, and the transistor is on when it is L. is assumed to be turned off.

By the way, it is necessary that the magnitudes of the currents flowing through the four excited windings are equal and always constant. Various means can be considered to make the current flowing in each of the four excited windings a constant current, but it is possible to make the current in these windings a constant current with the simplest possible circuit configuration. This is required from the viewpoint of cost and reliability.

The present invention satisfies the above-mentioned requirements, and uses a simple circuit configuration to determine the current flowing through each of the four excited windings in the pentagon drive system of a five-phase pulse motor. The object of the present invention is to provide a drive system for a five-phase pulse motor that can be driven by current. Therefore, the drive system of the five-phase pulse motor of the present invention consists of five windings connected in a link shape, and five pairs of transistors whose junction point is connected to one of the junction points of the windings. , a power supply connected to one of the five transistor pairs, a current detection resistor connected to the other of the five transistor pairs, and a current detected by the current detection resistor as a reference value. An excitation signal to be supplied to the comparison circuit to be compared and the transistor on the power supply side or the transistor on the current detection resistor side of the five transistor pairs is input to one input terminal,
The other input terminal includes five gate means into which the output of the comparison circuit is input, and an excitation signal supply circuit that supplies excitation current to the transistors constituting the five transistor pairs, and the excitation signal The supply circuit turns on only one of the transistors in each transistor pair, and in a certain cycle, puts two transistor pairs connected to both ends of one winding in the same state,
The two transistor pairs on both sides of the transistor pair in the same state are set to different states, the remaining transistor pair is set to the same state as the two transistor pairs in the same state, and in the next cycle, the same state is set. In a drive system for a five-phase pulse motor configured to output an excitation signal so as to invert the state of one of the two transistor pairs that take the state, both ends of one winding Current is supplied to the winding at the point when the state of one of the two transistor pairs, which are connected to each other and take the same state, is reversed and current begins to flow through the winding, which had no current. The excitation signal generation circuit outputs an excitation signal to turn off transistors other than the transistors involved. Hereinafter, the present invention will be explained with reference to the drawings.

Figures 4 to 6 explain one embodiment of the present invention, and Figure 4 shows the circuit configuration of a five-phase pulse motor drive system that employs constant current control, which is the basis of the present invention. FIG. 5 is a time chart showing the excitation signal waveform for the transistor in the present invention, and FIG. 6 is a diagram showing an embodiment of a circuit for creating the excitation signal as shown in FIG.

In Fig. 4, R is a current detection resistor;
COMP indicates a comparison circuit, and G1 to G5 indicate AND gates. Note that the same reference numerals as in FIG. 1 indicate the same parts.

In the state shown in FIG. 4A, current flows in the forward direction through the windings W1 and W4, current flows in the opposite direction through the windings W3 and W5, and no current flows through the winding W2. In addition, transistors Tr1L, Tr2H, Tr3
The excitation signals for H, Tr4L, and Tr5H are on signals, and the other transistors are turned off.
A current I is applied to each of the windings W1, W3, W4, and W5.
If , then a current of 4I flows through the resistor R. When the voltage across the resistor R is greater than the reference voltage Verf, the comparison circuit COMP outputs logic "0",
As a result, all gates G1 to G5 are closed. When the voltage across the resistor R is lower than the reference voltage, the comparator circuit COMP outputs logic “1” and the gate G
All from 1 to G5 open.

Next, in order to rotate the motor one step, it is assumed that the state shown in FIG. 4B is set. The only change in the state of the transistor group at this time is that the transistor Tr3L is turned on and the transistor Tr3H is turned off. As a result, the current in the winding W3 decreases at a rate determined by the circuit time constant, current begins to flow through the winding W2, and this current increases at a rate determined by the circuit time constant. Even during such phase excitation switching transition period, there is no change in the excitation signals for the windings W1, W4, and W5, and the reference value of the comparison circuit COMP is 4I, so the current in the winding 3 falls and the winding While the current in W2 is about to rise, the current values in the windings W1, W4, and W5 increase to satisfy the reference value 4I of the comparison circuit COMP. Therefore, when the transition period ends and a stable state is reached, the current value of the winding W2 from which the current newly started does not reach I, and the current value of the other winding W2 does not reach I.
A current greater than I flows through 1, W4, and W5. Such unbalance between the windings increases each time the excitation phase is switched, and has an adverse effect on the smooth rotation of the five-phase pulse motor. An object of the present invention is to prevent such imbalance of current between the excited windings. To achieve this purpose, transistors unrelated to the windings that newly start flowing current during the above-mentioned transient period are temporarily turned off to prevent the current from increasing in the windings that continue to flow the current from the previous excitation, and are constantly energized. Allow equal current to flow through each winding. Each transistor Tr1H, Tr1L...Tr5H, Tr
The excitation signal given to 5L is as shown in FIG. The transistors whose excitation signal is on during the period indicated by ○A in Figure 5 are Tr1L, Tr2H, and Tr.
3H, Tr4L, and Tr5H, but since it is the transistors Tr2H and Tr3L that are related to the winding W in which the current starts to flow during the period indicated by ○ in FIG. 5, the other transistors Tr1L, Tr4L,
Tr5H is temporarily turned off, and windings W1, W4,
Prevents W5 current increase.

FIG. 6 shows one embodiment of a circuit for generating an excitation signal for a transistor such as that shown in FIG. In Figure 6, CONT is a counter, M
indicate read-only memories, respectively. A clock and a direction designation signal are input to the counter CONT. The direction designation specifies whether the counter should operate as an up counter or a down counter. counter
The count value of CONT is input to the read-only memory M as an address, and as a result, 10-bit data is output. Of the 10-bit data output from read-only memory M, bits 1 to 5 serve as excitation signals for transistors Tr1L to Tr5L, and bits 6 to 10 serve as excitation signals for transistors Tr1H to Tr5H.

Next, the operation of the circuit shown in FIG. 6 will be explained. Now, when the content of the counter CONT is 10, the transistor Tr
Turn off the excitation signal for 3H, turn off the transistor Tr
Assume that the excitation signal for 3L should be turned on. In this case, when the content of the counter CONT is 9, transistors Tr1H, Tr1L...Tr5H,
When the excitation signal to Tr5L becomes "0010100000" and the content of counter CONT is 10,
When the value becomes "0010010000" and the counter CONT is 11, the read-only memory M is configured so that it becomes "0110010110". At this time, the clock given to the counter CONT is the ON time required for each Tr.
It is assumed that the pulse width corresponds to the OFF time.

As is clear from the above description, according to the present invention, in the pentagon drive system of a five-phase pulse motor, the currents of the plurality of windings through which the excitation current flows are made equal and constant by a simple circuit configuration. I can do it.

[Brief explanation of the drawing]

Figures 1 to 3 idealize and explain the pentagon drive system of a five-phase pulse motor. Figure 2 is a time chart showing the waveform of the winding current; Figure 3 is a time chart showing the excitation signal waveform of the transistor; Figures 4 to 6 are diagrams showing the present invention. Fig. 4 is a diagram showing a circuit configuration of a drive system of a five-phase pulse motor that employs constant current control, which is the basis of the present invention, and Fig. 5 is a diagram illustrating an embodiment of the present invention. FIG. 6 is a diagram showing an excitation signal waveform for a transistor in FIG. 6, and shows one embodiment of a circuit for creating an excitation signal as shown in FIG. W1 to W5...Winding, Tr1H to Tr5
H and Tr1L to Tr5L...transistor, A to E...winding connection point, R...current detection resistor, COMP...comparison circuit, G1 to G
5...AND gate, CONT...counter, M...
...Read-only memory.

Claims (1)

[Claims] 1. Five windings coupled in a ring, five transistor pairs whose junctions are connected to one of the coupling points of the windings, and one of the five transistor pairs. A power supply, a current detection resistor connected to the other of the five transistor pairs, a comparison circuit that compares the current detected by the current detection resistor with a reference value, and a power supply for the five transistor pairs. an excitation signal to be supplied to the transistor on the side transistor or the transistor on the current detection resistor side is input to one input terminal, and the output of the comparison circuit is input to the other input terminal; five sets of transistors; an excitation signal supply circuit that supplies excitation current to the transistors forming the pair, the excitation signal supply circuit turning on only one transistor in each transistor pair;
In a certain cycle, two pairs of transistors connected to both ends of one winding are in the same state, and two pairs of transistors existing on both sides of the pair of transistors in the same state are in different states, The remaining transistor pairs are brought into the same state as the two transistor pairs taking the same state, and in the next cycle, the state of one of the two transistor pairs taking the same state is reversed. In the drive method of a five-phase pulse motor configured to output an excitation signal, 1
At the point in time when the state of one of the two transistor pairs connected to both ends of the winding and having the same state is reversed and current begins to flow through the winding which had no current, A drive control system for a five-phase pulse motor, characterized in that the excitation signal generation circuit outputs an excitation signal to turn off transistors other than those involved in supplying current to the windings.