PLUS+1 User Forum

PLUS+1™ Hardware => Controllers => Topic started by: sverreo on May 04, 2021, 08:43:54 PM

Title: Read PWM current signal
Post by: sverreo on May 04, 2021, 08:43:54 PM
Hi,

Does anybody know how to read a PWM current signal on an MC050-110?

There is an external ECU running a coil with a current output, and i want to know what the output is in percent in my software.
I'm an electric novice, but i think i need a RC filter before the MC50 input and read the signal as voltage? Anybody know how to calculate this or to get a stable signal?

I found out that the PWM signal is 1kHz, and from 600mA -> 2000mA.

When i now read the voltage or duty on the input it is not stable at all, and i tried filtering it in Guide using low-pass filter, but i can't get a stable signal...
Title: Re: Read PWM current signal
Post by: FluidPowerTom on May 05, 2021, 07:43:00 PM
There's no way for you to read this accurately by connecting the PLUS1 controller directly.  Even if you splice into the signal to read the PWM duty cycle you're then just siphoning off some of the current to the valve and potentially disrupting operation.  You'll need to look into a current measuring device that can go in series (so that it's not splicing out some of the current) that has a voltage or other type of output.  There's probably something out that that'll convert a 0 - 2A or 0 - 3A signal into 0 - 10V, but you might be hard pressed to find one that just goes in series and allows the current to pass through to the valve.
Title: Re: Read PWM current signal
Post by: FluidPowerTom on May 05, 2021, 07:44:32 PM
For just temporary monitoring you'd just want to put a multimeter in series with the valve coil and read the current that way.