I would like to drive CW and CCW (100% duty cycle) a 12v 5A linear actuator. I am looking at the G2 High-Power Motor Driver 18v17. Is this the right Pololu motor driver for this application? If yes, what capacitor (if any) should I place across the motor supply and ground?
Hello.
If your actuator uses a brushed DC motor and the 5A figure is the maximum current draw, the G2 High-Power Motor Driver 18v17 should work fine. As mentioned on the product page, we generally recommend using a capacitor of at least a few hundred μF.
You might also consider the VNH5019 carrier.
Brandon
Thank you for your reply. After posting my question, I also came across the VNH5019 carrier. Maybe I should buy both The capacitor makes sense for smoothing a PWM signal, but not sure why it would be needed on a DC (100% application) application. I am going to do more research on the topic and any insights you can provide would be appreciated. I assume both motor drivers would need the capacitor (let me know if I am wrong on the VNH5019).
For several years now, I have been using the VNH5019 module for 12V, 5A linear actuators operating greenhouse windows, without problems.
The reason for the capacitor across the driver module motor power inputs is to dampen high voltage spikes in power leads, described here: Pololu - Understanding Destructive LC Voltage Spikes
Thank you for the recommendation based on real world experience and the link. I am planning on adding a 1000uF 25V Aluminum Electrolytic Capacitor. Is that what you use in your circuit? Thank you again.
I use various values, like 330 or 470 uF, but 50V for an added safety factor.
For a DC application, those values sound about right.