SU1295502A1 - Control device for four-phase stepping motor - Google Patents

Abstract

The invention relates to electrical engineering, to the control of electrical machines .; The goal is to increase reliability and efficiency. The device contains a control unit 1 that sets the required sequence of switching keys 7-10 and pulses the average value of the current in the phases of the electric motor 2 according to a signal from the current sensor 12 connected between the junction points 4, 6 and 3, 5 connected to each pair keys 8, 10 and 7, 9, by controlling the even and odd switch keys. To test the next step by the electric motor, the control unit 1 closes the key 8 and opens the key 10. The current in the winding 4 drops as it flows along the circuit containing elements 14 4, 12, 3, 7. At the same time, the current in the winding 6 rises, passing along the circuit containing elements 11, 10, 6, 12j 3, 7. The current in the winding 3 is maintained at a predetermined level without a circuit by the control circuit 1 and the key on the signal C of the current sensor 12, which increases reliability and efficiency. 1 il. (L with Е & 0 К ii 51 X with f ff 10 with СД СП СП ю

Description

The invention relates to the control of electric machines and can be used to create electric drives with stepper motors.

The purpose of the invention is to increase reliability and efficiency,

The drawing shows the functional diagram of the device.

The device consists of a control unit 1 of a stepper motor 2, the phase windings 3-6 of which are connected via switches 7-10 to a power supply 11, a resistive current sensor 12 and reverse diodes 13-16. Moreover, the keys 7-10 are divided into pairs 8, 10 and 7, 9, which are connected to different poles of the power source 11. A resistor current sensor 12 is connected between the connection points of phases 4, 6 and 3, 5 connected to each pair of keys 8, 10 and 7, 9, respectively, as well as diodes 13-16 ,. connecting common points of phases 3-6 and keys 7-10 with the poles of the power source 1 1.

The device works as follows.

Control unit 1 sets the required switching sequence

keys 7-10 and pulses jg is set depending on the need to stabilize the average current in the phases of motor 2 by a signal from the resistive current sensor 12 by controlling the even or odd switch keys.

In describing the operation of the device, for definiteness, it is assumed that the function of the current regulator performs odd keys, although this is not critical for the operation of the switch, since the circuit is symmetrical with respect to the current sensor.

Let, for example, at the first moment of time switches 7 and 8 be turned on. In a circuit containing elements 11, 8, 4, 12, 3 and 7, an increasing current arises. As soon as the current reaches a predetermined value, the control circuit 1 by the signal from the resistive current sensor 12 closes the key 7.

The current due to the energy stored in the inductance of the windings 3 and 4 flows through the circuit containing elements 8, 4, 12, 3 and 13. After some time, the current decreases to a value where the control circuit 1 turns on the key 7 again, the current in the windings Zi4 begins to grow. Further, the processes are repeated in the windings of the electric motors.

The heater is maintained at a predetermined average current.

For testing by the electric motor 2 of the next step, the control unit 1 closes the key 8 and opens the key 10. The current in the winding 4 drops as it flows through the circuit containing elements 14, 4, 12, 3 and 7. At the same time, the current in the winding 6 increases the passage along the circuit containing elements 11, 10, 6, 12, 3 and 7. The current in the winding 3 is maintained at a predetermined level by the control circuit 1 and the key 7 according to a signal from the resistive current sensor 12.

For processing by the motor 2 of the next step, the control unit 1 closes the key 7 and opens the key 9. The functions of the current regulator are then executed by the key 9, The processes of rise and fall of the current in the motor windings proceed in the same way as described.

For processing by the motor 2 in the following steps, the control unit 1 closes the key 10 and opens the key 8, then closes the key 9 and unlocks the key 7. Then all the processes are repeated. Key Switching

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direction of rotation of the electric motor.

Thus, the inclusion of a current sensor between the windings of a step electric motor, connected to one and the other terminals of the power source, made it possible to eliminate current surges through the winding and the key when switching windings and thereby increase the reliability and efficiency of the device.

Claims (1)

Invention Formula A device for controlling a four-phase stepper motor in a pair-switching mode, containing a power source, a control unit, keys connected to the motor phases j, connected in pairs to the power supply poles, a current sensor and diodes connecting the common points of the phases and the keys to the poles power supply, and the phases connected to one pair of keys are connected between their own, characterized in that, in order to increase reliability and efficiency, a resistive current sensor is connected between the connection points of the phases connected to each pair keys.