Stepper motor 12 features, which do you know?
Stepper motor 12 features, which do you know?
(1) Even if it is the same stepper motor, when using different drive schemes, the characteristics of the moment frequency vary greatly.
(2) When the stepping motor is in operation, the pulse signal is added to the windings of each phase in turn according to a certain sequence (the way in which the winding is controlled by the annular distributor in the driver to turn off and on).
(3) Stepping motor is different from other motors. Its nominal rated voltage and rated current are only reference values; because the stepping motor is powered by pulse, the power supply voltage is its highest voltage, not the average voltage, so stepping The motor can work beyond its rated value. However, the selection should not deviate too far from the rated value.
(4) Stepper motor does not accumulate error: The accuracy of a typical stepper motor is 3 to 5 percent of the actual step angle and does not accumulate.
(5) The maximum allowable temperature of stepper motor: If the temperature of stepper motor is too high, the magnetic material of the motor will be demagnetized firstly, which will cause the torque to drop even if it is out of step. Therefore, the maximum temperature allowed by the appearance of the motor should depend on the magnetic material of different motors. The demagnetization point; In general, the demagnetization point of magnetic materials are above 130 degrees Celsius, and some even as high as 200 degrees Celsius or more, so the external temperature of the stepper motor is completely normal at 80-90 degrees Celsius.
(6) The torque of the stepping motor will decrease with the increase of the rotation speed: When the stepping motor rotates, the inductance of each phase winding of the motor will form a back electromotive force; the higher the frequency, the larger the back electromotive force. Under its effect, the phase current of the motor decreases with increasing frequency (or speed), resulting in a decrease in torque.
(7) The stepping motor can operate normally at a low speed, but if it is higher than a certain frequency, it cannot be started and it is accompanied by howling. The stepper motor has a technical parameter: no-load starting frequency, that is, the pulse frequency of the stepping motor can start normally under no-load conditions. If the pulse frequency is higher than this value, the motor cannot start normally, and losing steps or stalling may occur. In the case of a load, the starting frequency should be lower. If the motor is to be rotated at a high speed, the pulse frequency should have an acceleration process, that is, the starting frequency is low, and then it is increased to a desired high frequency at a certain acceleration (the motor speed is raised from low speed to high speed).
(8) The power supply voltage of the hybrid stepping motor driver is generally a wide range (for example, the power supply voltage of the IM483 is 12 to 48 VDC), and the power supply voltage is usually selected according to the operating speed and response requirements of the motor. If the motor operates at a higher speed or responds faster, then the voltage value is also high, but note that the ripple of the supply voltage must not exceed the maximum input voltage of the driver, otherwise the driver may be damaged.
(9) The power supply current is generally determined based on the output phase current I of the driver. If a linear power supply is used, the supply current may generally be 1.1 to 1.3 times the I. If a switching power supply is used, the supply current may generally be 1.5 to 2.0 times I.
(10) When the offline signal FREE is at a low level, the current output from the driver to the motor is cut off and the motor rotor is in a free state (offline state). In some automation equipment, if it is required to directly rotate the motor shaft (manual mode) when the drive is not powered, the FREE signal can be set low to take the motor offline for manual operation or adjustment. After the manual completion, set the FREE signal again to continue automatic control.
(11) Use a simple method to adjust the direction of rotation of the two-phase stepper motor after power on. Simply swap the A+ and A- (or B+ and B-) motor and driver connections.
(12) Four-phase hybrid stepper motors are generally driven by two-phase stepper drives. Therefore, four-phase motors can be connected in two phases using series connection or parallel connection. Serial connection method is generally used when the motor rotates at a low speed. The output current of the driver needed at this time is 0.7 times of the motor phase current, so the motor heat is small. The connection method is generally used when the motor rotates at a high speed (also called high speed connection). Actually, the required driver output current is 1.4 times the motor phase current, and thus the stepper motor generates a large amount of heat.
