October 12, 2023 by Crystal Lin
3D printing (3DP) is a type of rapid prototyping technology. It is a technology that uses adhesive materials such as powdered metal or plastic to construct objects by printing layer by layer based on digital model files.
How to make a stepper motor completely silent?
SpreadCycle
Although high subdivision can solve the low-frequency vibration in most cases; advanced current control PWM chopper mode such as TRINAMIC's SpreadCycle algorithm, these functions in hardware greatly reduce vibration and jitter, which also satisfies most requirements. It is also suitable for high-speed motion applications. However, there will still be audible noise and vibration in the chopper mode based on current control, mainly due to the desynchronization of the motor coil, the adjustment noise of a few millivolts on the sense resistor and the PWM time base. Errors, these noises and vibrations are not allowed in some high-end applications, slow running or medium-speed motion applications, and any noise and situations where noise is not allowed.
TRINAMIC's StealthChop algorithm is also implemented through hardware, fundamentally making the stepper motor silent. But how does the Stealthchop function affect the stepper motor? Why does the motor not produce noise and vibration? Stealthchop uses a voltage modulation mode based on current feedback. For example, SpreadCycle has a completely different approach. Instead, it uses a new technology based on voltage chopper mode, which ensures silent and smooth motion of the motor.
TMC5130 - a small, compact stepper motor drive control chip with StealthChop mode. TRINAMIC has improved the modulation mode. In order to minimize the impact of current fluctuations on dynamic performance, TMC5130 uses current feedback to control voltage modulation, which allows the system to adapt to the parameters and operating voltage of the motor. Small oscillations caused by the direct current control loop algorithm are eliminated.
The zero-crossing effect in StealthChop mode is perfect: when the current signal changes from positive to negative or negative to positive, there will be no transition area but a continuous crossing of zero. Because the current is modulated according to the PWM duty cycle It is controlled by Ratio. At 50% PWM duty cycle, the current is 0. StealthChop adjusts the PWM duty cycle to adjust the motor current. The PWM frequency is a constant. In contrast, the current-controlled chopper adjusts the motor by regulating the frequency. Current, the fluctuation of current here is relatively large. In addition, the fluctuation of current will generate eddy current in the permanent magnet rotor of the motor, which will lead to the loss of power consumption of the motor.
The sound emitted by these PWMs with changing frequencies is within the audible range and will emit a hissing sound, and the electronic stator will produce greater noise due to magnetostriction, which will in turn cause vibrations in the mechanical system. StealthChop A fixed chopping frequency will not have these problems. There is no change in chopping frequency except the change of the microstep phase sequence distributor when the motor is running.
In addition to the unavoidable sound of the friction of the steel balls in the motor bearings, StealthChop can drive the motor to work at an extremely fine sound, and can control the motor sound below 10dB decibels, and the noise is much lower than the traditional current control method. We It is known from physics that a 3dB decibel reduction will reduce the noise level by half. The following video is a performance comparison of TRINAMIC products TMC2100, TMC2130 and A4988
http://v.youku.com/v_show/id_XMzMzMzQxOTEyOA==.html?spm=a2h0j.11185381.listitem_page1.5!10~A
What has changed for stepper motors?
Nowadays, the stepper motor is still a very economical motor. It has been used for many years and still uses the same materials, production processes and assembly techniques as before.
But compared to the past, stepper motors are now driven by simpler control units, more advanced algorithms and more highly integrated microelectronics, allowing the original motor to unleash greater potential. There is more information in the drive circuit close to the motor It is acquired and processed in the drive current in real time to optimize motor control. StealthChop is a perfect example. Its algorithm is closely related to PWM chopper. In addition, this information can also be fed back to the higher application control layer, while traditional All of TRINAMIC's stepper drive solutions are one-way (pulse/direction), and all TRINAMIC's intelligent stepper motor drive solutions are two-way communication. These interfaces can also monitor different statuses and diagnostic information. This can increase the reliability of the system and provide system performance.
StealthChop silent drive technology is very suitable for 3D printing, desktop CNC, high-end CCTV, in vitro diagnostic equipment, medical testing equipment, etc.
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