RoboteQ AX500 Computer Hardware User Manual


 
General Operation
38 AX500 Motor Controller Users Manual Version 1.9b. June 1, 2007
User Selected Current Limit Settings
The AX500 has current sensors at each of its two output stages. Every 16 ms, this current
is measured and a correction to the output power level is applied if higher than the user
preset value.
The current limit may be set using the supplied PC utility. Using the PC utility is it possible
to set the limit with a 0.125A granularity from 1.625 to 15A
During normal operation, current limiting is further enhanced by the techniques described
in the following sections.
Temperature-Based Current Limitation
The AX500 features active current limitation that uses a combination of a user defined pre-
set value (discussed above) which in turn may be reduced automatically based on mea-
sured operating temperature. This capability ensures that the controller will be able to work
safely with practically all motor types and will adjust itself automatically for the various load
conditions.
When the measured temperature reaches 80oC, the controllers maximum current limit
begins to drop to reach 0A at 100oC. Above 100oC, the controllers power stage turns itself
off completely.
TABLE 3. Effect of Heatsink temperature on Max Amps Limit
Temperature Max Amps
Below 80 oC 15A
80 oC 15A
85 oC 10A
90 oC 7.5A
95 oC 2.5A
100 oC 0
Above 100 oC Both Power Stages OFF
Position Sensor
Gear box
Position Feedback
FIGURE 16. Motor with potentiometer assembly for Position operation