So I am fairly new to using linear actuators and the pololu jrk motor controllers. I have a couple of questions. First off I was wondering if there is an option to stop power going to the motor if/when feedback is lost. Secondly if it is possible to cut power to the motor if the current exceeds a specified limit.
I am pushing an object and want it to stop if it gets too much resistance or if the feedback somehow gets disconnected.
Thank you in advance for any/all help you can provide.
Hello, JCrandall.
The Jrk controllers support both of the features you described. You can configure the settings on the Jrk G2 24v13 using the Jrk G2 Configuration Utility (which is available in the “Resources” tab of the product’s web page).
You can use the “feedback disconnect” feature by providing the 5V to the feedback potentiometer through the AUX pin on the Jrk and checking the “Detect disconnect with power pin (AUX)” option in the “Feedback” tab of the Jrk G2 Configuration Utility. A description of how this feature works can be found in the “Analog/frequency feedback handling” section of the Jrk G2 user’s guide.
The Jrk G2 has 2 options for monitoring and limiting the current: Hard current limit and Soft current limit; both are found in the “Motor” tab of the Jrk G2 Configuration Utility. The “Motor settings” section of that same user’s guide has information on both of these settings.
“Hard current limit" sets the hardware current limit for the Jrk’s motor driver circuit; when the motor current exceeds this value, the driver will actively limit it with current chopping.
“Soft current limit" sets the motor current threshold for the “Soft overcurrent” error. If the Jrk’s motor current measurement exceeds this value, and the “Soft overcurrent” error is enabled, then the Jrk will set the corresponding error flag, which will cause it to respond depending on the error response option configured. The available error response options can be found in the “Error handling” section of the user’s guide.
Brandon
