MOONS’ offers several families of hybrid step motors with a different number of phases and step angles. Each has a combination of advantages that are better suited to specific applications.
• 2 Phase – 1.8 degree step angle
This is the most popular step motor. It has a great combination of torque, speed and accuracy. Due to their high volumes, drives for 2 phase motors are very common and economical.
The basic method of control is to have the motor make one full step as the drive applies full current to the motor windings. This causes the motor to move in full step increments. When the motor is stepped at different rates it may make a distinctive sound and can vibrate (resonate) at certain speeds. This is not a problem for most applications. If it is an issue, motors can be controlled with micro-stepping drives that smooth motor torque. And many times, resonate speeds can simply be avoided by programming the drive.
MOONS’ offers 2 phase 0.9 degree step motors, and three phase 1.2 degree step motors, for applications that need even more accuracy, or motion that is very smooth and quiet.
• 2 Phase – 0.9 degree step angle
Because each step moves only ½ the distance of 1.8 degree motors, these motors have higher accuracy and very smooth movement. The drive for this motor is exactly the same as the 2 phase, 1.8 degree motors. For the same speed, these motors must have a step rate that is 2 times that of a 1.8 degree motor. This higher step rate leads to less torque at high speeds.
However, for many applications high speed is not needed, or higher voltage drives can be used to increase torque at high speeds.
An example of a good application for 0.9 degree motors are security cameras. These motors allow the camera to be precisely moved without “camera shake” which causes the picture to vibrate. MOONS’ offers small encapsulated sizes that reduce camera package size, and helps withstand the outdoor environment.
• 3 Phase – 1.2 degree step angle
The use of three phases inherently helps to reduce torque ripple and smooth motor performance. 3 phase motors require a 3 phase drive that is different than the drive for 2 phase motors. As compared to the 1.8 degree two phase motors, the low speed torque is somewhat less. But design improvements introduced by MOONS’, minimizes this difference. High speed torque can also be comparable. In addition, MOONS’ size 24 three phase motors are available with PowerPlus technology, for maximon torque.
3 phase motors are used where maximum performance, and very quiet, smooth precise movement is need. An example of a good application for three phase motors is in performance lighting. These spotlights lights need quick movement, and quiet operation so as not disturb the performance.