Filtering current sense output from G2 18v17

Support Motor controllers/drivers and motors
1

I want to use the G2 18v17 to drive brushed DC motors with constant current control.

To implement this I need to get a current feedback to control a PWM source such as an LM3524.

The input to the PWM controller needs to be a DC signal proportional to the average motor current.

The CS (current sense) output of the 18v17 is a big noisy mess.
Even if I get rid of the noise, the current sense signal is a square wave synchronized with the PWM signal.

Before I go and try to discover the wheel myself of how to filter the CS output and get a clean DC signal I wanted to check if anyone has dealt with this problem before.

2

Hello.

Unfortunately, we do not have any additional suggestions for using the G2 High-Power Motor Driver 18v17 board’s current sensor output that way. As we mention on the product page, the CS output is only active while the H-bridge is in drive mode, so that aspect of the behavior you are seeing is inherent to how the current sense feature on this board works.

If you want to implement constant current control, I recommend adding a dedicated, in-line current sensor to your system, like one of the Hall effect-based current sensors we offer.

- Patrick