Noise from VRM

[peronis]

Hi all,

We have a electrical noise coming from our VRM. The only component wired to it is the router.

We switched to another VRM we had, and the same problem exists. Is this a problem, or is it normal for the operation?

If it isn't normal, then I think it might be interference from our wire runs, since we have the wires from two motors and 3 solenoids all running in a bunch from one side of the robot to another. I hear it though even if the robot is disabled and no current is going through them. So, I ruled this out.

Thoughts or suggestions would be helpful.

Thank you

[Alan Anderson]

Originally Posted by peronis

We have a electrical noise coming from our VRM.

What connections are you seeing this noise on? How are you detecting it?

[ozrien]

How exactly is the robot not functioning? Is the robot itself misbehaving?

[crollison]

Have the same issue, it's a very high pitched electrical kind of sound. Unplug the router and it stops. Doesnt' seem to be effecting anything, but does bother me some.

[ozrien]

Hearing an audible whine is normal with the VRM. It's switching freq is near the audible range, and it's load dependent so removing the load will silence it.

[Tom Line]

Boost regulator? The old PDB used to whine. We always claimed we had a squirrel in the bot somewhere.

[peronis]

Thank you for the responses. Everything works fine on the bot. The noise is from the vrm itself. I was wondering if other teams had vrms without this happening?

Definitely the circuitry inside, just concerned about comms going down at some inopportune time, or the router not receiving a constant 5v

[philso]

It seems from your posts that you are concerned about an audible noise coming from the VRM rather than electrical noise that you are measuring with some instrument like an oscilloscope. It also seems that you are not seeing any failure or mis-operation of any sort. If this is the case, ignore the audible noise. It is common for components in circuitry like the VRM to emit audible noise while operating correctly. The presence or absence of the audible noise is not a reflection on the reliability of the VRM.