TMCM-111-56 Manual
15
Copyright © 2006, TRINAMIC Motion Control GmbH & Co. KG
5.8 Continuous Current restrictions
The module is designed as a microstepping module, with sine wave currents (sine and cosine) driving both
coils. The current peak of the sine wave can be as high as 7.1A, when the RMS current is set to 5A. The
mean motor current (RMS) is calculated by dividing the peak current by 1.41.
The compact design of the module does not allow to continuously drive the full current unless forced air
cooling is used to keep the board temperature below 105°C, because of excessive heat generation. However,
since continuous maximum current operation also shortens the lifetime of the motor, this is in most cases
no restriction.
Operation at or near the limiting values for an extended period of time should be avoided.
Please also refer to the comment on the thermal protection feature.
The following limits apply:
Environment conditions
Mounting conditions
RMS current @
24V supply
RMS current @
36V supply
free air convection possible
(env. Temp. max 45°C)
Module operating in free
air, no housing
4A or
5A at 50%
operation duty
cycle
3A or
5A at 40%
operation duty
cycle
Temperature at cooling
plane < 70°C
Housing mounted to metal
part
5 A
5 A
Temperature at cooling
plane< 85°C *)
Housing mounted to motor
back bell
5A 4A
Table 5.2: Continuous current restrictions
*) max. motor operating temperature is 85°C. Limit motor current if the motor temperature is higher than
85°C (reduce duty cycle).
