QSH5718-41-30-047 TRINAMIC, QSH5718-41-30-047 Datasheet - Page 8

• Manufacturer Part Number: QSH5718-41-30-047
• Description: STEPPER MOTOR, 1.8DEG, 3.0A, 0.47NM
• Manufacturer: TRINAMIC

Specifications of QSH5718-41-30-047

• Torque Max: 47N-cm
• Current Rating: 3A
• No. Of Phases: 2
• Resistance: 600mohm
• Inductance: 1.5mH
• Inertia: 77g-cm2
• External Depth: 57mm
• External Length / Height: 41.0mm
• External: RoHS Compliant
• Coil Type: Bipolar
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes

5 Considerations for Operation
The following chapters try to help you to correctly set the key operation parameters in order to get a
stable system.
5.1 Choosing the best fitting Motor for an Application
For an optimum solution it is important to fit the motor to the application and to choose the best mode
of operation. The key parameters are desired motor torque and velocity. While the motor holding
torque describes the torque at stand-still, and gives a good indication for comparing different motors, it
is not the key parameter for the best fitting motor. The required torque is a result of static load on the
motor, dynamic loads which occur during acceleration / deceleration and loads due to friction. In most
applications the load at maximum desired motor velocity is most critical, because of the reduction of
motor torque at higher velocity. While the required velocity generally is well known, the required torque
often is only roughly known. Generally, a longer motor and a motor with a larger diameter delivers a
higher torque. But, using the same driver voltage for the motor, the larger motor earlier looses torque
when increasing motor velocity. This means, that for a high torque at a high motor velocity, the smaller
motor might be the better fitting solution.
Please refer to the torque vs. velocity diagram to determine the best fitting motor, which delivers
enough torque at all desired velocities.
Hints:
5.2 Motor Current Setting
Basically, the motor torque is proportional to the motor current, as long as the current stays at a
reasonable level. At the same time, the power consumption of the motor (and driver) is proportional to
the square of the motor current. Optimally, the motor should be chosen to bring the required
performance at the rated motor current. For a short time, the motor current may be raised above this
level in order to get increased torque, but care has to be taken in order not to exceed the maximum
coil temperature of 130°C respectively a continuous motor operation temperature of 90°C.
Copyright © 2006, TRINAMIC Motion Control GmbH & Co. KG
Percentage of
Q: How to determine the maximum torque required by your application?
A: Just try a motor which should roughly fit. Take into consideration worst case conditions, i.e.
minimum driver supply voltage and minimum driver current, maximum or minimum environment
temperature (whichever is worse) and maximum friction of mechanics. Now, consider that you want
to be on the safe side, and add some 10 percent safety margin to take into account for unknown
degradation of mechanics and motor.
rated current
150%
125%
100%
85%
75%
50%
38%
25%
0%
Percentage of
motor torque
see detent
≤150%
torque
125%
100%
85%
75%
50%
38%
25%
Table 3: Motor current settings
motor power dissipation
= 2 * I
Percentage of static
RMS_RATED
225%
156%
100%
72%
56%
25%
14%
6%
0%
* R
COIL
Comment
Limit operation to a few seconds
Operation possible for a limited time
Normal operation
Normal operation
Normal operation
Reduced microstep exactness due
to torque reducing in the magnitude
of detent torque
-“-
-“-
Motor might loose position if the
application’s friction is too low