Hi all,
The kids just wired up the electronics for prototyping and such. The power distribution board seems to be emitting a high frequency noise, not unlike the CRT TV or monitor noise you hear sometimes, or even a bad bearing in a heatsink type noise. I am not familiar with the inner workings, but I am pretty sure last years board didn’t have this.
We disconnected all the connections to the board except the battery, and tried to narrow it down to maybe a bad snap action breaker to no avail.
I feel pretty worried that the board might be bad, or have a chance of failing at a bad time. Should I contact FIRST about this? Has anyone observed the same noise? Thoughts?
In case you didn’t find it yet, the power supplies on the PD can and do make some noise that is load related. When robot motors are running you will never hear it.
Al beat me to it, but I’ll also add just double check and make sure you are using the correct breakers.
Breakers are unrelated. Al is correct. This is a side effect of making the boost regulators burly enough to handle very low input voltages. During normal operation they don’t have much to do relative to their capability, so they whine out of boredom (discontinuous / burst mode operation).
The two possible causes are loose inductor coils, or the natural switching noise in the power supply circuit.
Both are harmless, but if it bugs you it doesn’t really hurt to use your old PD board (as far as I know). You’ll see this issue happen in Desktop PC power supplies, LCD/CRT displays, and all sorts of other electronics from time to time, it’s considered harmless (but kinda annoying).
Just to recap everything here with an historical footnote.
1st of all the noise is nothing to worry about. It will change under load and will get drowned out when you get your robot going.
Years ago when they first came out with switching power supplies it was common for them to make noise and annoy people. Back in the day there were devices I could hardly stand because of the high pitched switcher noise.
Over time, two things have happened. 1) switcher frequencies have increased, beyond the range of human audibility. 2) components have improved so that they don’t vibrate as much.
Bottom line - don’t worry about it.
re: 3) my ears have become less sensitive, one of the joys of getting old.
another thing about getting older is my nose doesn’t work so well anymore, meaning tasty junk food is less attractive and healthy food is more tolerable.
between better eating and staying active with robotics, I lost 40 lbs.
robotics is a great weight loss program., which has nothing at all to do with this thread.