https://youtu.be/FSwZQtqWyHw Can that whining noise be easily eliminated? I am assuming its origin is easy for some to guess. It uses brushless motors controlled by an "electronic speed control" (ESC). There is a large cap across each ESC supply plus and minus. I tried adding a 1000 �F low ESR capacitor on the battery input but that didn't help. Thanks.
How to stop electrical whining noise?
Started by ●December 26, 2018
Reply by ●December 26, 20182018-12-26
The blades. Also, emitting a shitload of sound is inefficient. Anything that makes unwanted motion or energy is wasting. Yeah they probably want me to teach greengineering but fuck all that. What you hear is the fans' blades interacting with the air, but which then the sound is transmitted to you. And others, who might bitch. Bottom line, the sound is not coming from the motors.
Reply by ●December 26, 20182018-12-26
On 2018-12-26, John Doe <always.look@message.header> wrote:> https://youtu.be/FSwZQtqWyHw > > Can that whining noise be easily eliminated? > > I am assuming its origin is easy for some to guess. > It uses brushless motors controlled by an "electronic speed control" > (ESC). There is a large cap across each ESC supply plus and minus. I > tried adding a 1000 µF low ESR capacitor on the battery input but that > didn't help.my guess it that it's coming from the motors. -- When I tried casting out nines I made a hash of it.
Reply by ●December 26, 20182018-12-26
On 26-12-2018 5:02, John Doe wrote:> https://youtu.be/FSwZQtqWyHw > > Can that whining noise be easily eliminated? > > I am assuming its origin is easy for some to guess. > It uses brushless motors controlled by an "electronic speed control" > (ESC). There is a large cap across each ESC supply plus and minus. I > tried adding a 1000 �F low ESR capacitor on the battery input but that > didn't help. > > Thanks. >maybe magnetically induced noise? Bigger caps cannot cure that.
Reply by ●December 26, 20182018-12-26
On Wed, 26 Dec 2018 04:02:07 -0000 (UTC), John Doe <always.look@message.header> wrote:>https://youtu.be/FSwZQtqWyHwThe video is from 2005.>Can that whining noise be easily eliminated?Maybe. Propeller tip vortexes and cavitation are making the noise. The only way to reduce that is to reduce RPM's, which means you'll need larger diameter props, or by clever prop design. Some manufacturers offer low-noise props. I've never tried any, so I have no clue if they actually work. <https://airbuzz.one/why-i-dont-use-the-low-noise-propellers-anymore/> I couldn't find any for Walkera, just DJI: <https://www.amazon.com/Anbee-Low-Noise-Propeller-Quick-Release-Platinum/dp/B07795ZT1P> Various low-noise propeller tests: <https://www.youtube.com/results?search_query=low+noise+propeller>>I am assuming its origin is easy for some to guess.I never guess when I can also test. 1. Take a vinyl hose and cram one end in your ear. Use the other end to determine the source of the noise. I think you'll find that it makes the most noise near the tips of the props. 2. Remove the props from all the motors. Run the quadcopter without the props. What's left is the contribution made by the brushless motors, which I think you'll find isn't very much.>It uses brushless motors controlled by an "electronic speed control" >(ESC). There is a large cap across each ESC supply plus and minus. I >tried adding a 1000 �F low ESR capacitor on the battery input but that >didn't help.Filtering the DC power inputs isn't going to do anything useful. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●December 26, 20182018-12-26
On 12/26/2018 12:13 AM, Jasen Betts wrote:> On 2018-12-26, John Doe <always.look@message.header> wrote: >> https://youtu.be/FSwZQtqWyHw >> >> Can that whining noise be easily eliminated? >> >> I am assuming its origin is easy for some to guess. >> It uses brushless motors controlled by an "electronic speed control" >> (ESC). There is a large cap across each ESC supply plus and minus. I >> tried adding a 1000 µF low ESR capacitor on the battery input but that >> didn't help. > > my guess it that it's coming from the motors. > >Does the noise stop when you turn it off? Right. well. There's yer problem
Reply by ●December 26, 20182018-12-26
On 12/26/2018 12:58 AM, Jeff Liebermann wrote:> On Wed, 26 Dec 2018 04:02:07 -0000 (UTC), John Doe > <always.look@message.header> wrote: > >> https://youtu.be/FSwZQtqWyHw > > The video is from 2005. > >> Can that whining noise be easily eliminated? > > Maybe. Propeller tip vortexes and cavitation are making the noise. > The only way to reduce that is to reduce RPM's, which means you'll > need larger diameter props, or by clever prop design. Some > manufacturers offer low-noise props. I've never tried any, so I have > no clue if they actually work. > <https://airbuzz.one/why-i-dont-use-the-low-noise-propellers-anymore/> > > I couldn't find any for Walkera, just DJI: > <https://www.amazon.com/Anbee-Low-Noise-Propeller-Quick-Release-Platinum/dp/B07795ZT1P> > > Various low-noise propeller tests: > <https://www.youtube.com/results?search_query=low+noise+propeller> > >> I am assuming its origin is easy for some to guess. > > I never guess when I can also test. > 1. Take a vinyl hose and cram one end in your ear. Use the other end > to determine the source of the noise. I think you'll find that it > makes the most noise near the tips of the props. > 2. Remove the props from all the motors. Run the quadcopter without > the props. What's left is the contribution made by the brushless > motors, which I think you'll find isn't very much. > >> It uses brushless motors controlled by an "electronic speed control" >> (ESC). There is a large cap across each ESC supply plus and minus. I >> tried adding a 1000 µF low ESR capacitor on the battery input but that >> didn't help. > > Filtering the DC power inputs isn't going to do anything useful. >Right the noise is mechanical, not electrical. Parts that are rotating and making sound. If it were a jet engine OP would be looking for some kind of "hush kit"
Reply by ●December 26, 20182018-12-26
It sounds to me like it is switching noise from the motor drive, which causes movement of the motor windings It sounds to be a steady noise frequency which it won’t be if it is related to the blades No way to change it, except to change the motor control SW or filter the output to the motor to reduce the switching current ripple Cheers Klaus
Reply by ●December 26, 20182018-12-26
Jeff Liebermann <jeffl@cruzio.com> wrote:> John Doe <always.look@message.header> wrote: > >> https://youtu.be/FSwZQtqWyHw > > The video is from 2005.The video is from 2015. I thought about posting a disclaimer after clicking Send, but it's not necessary. The video is a concise and accurate example of the same noise from the same model drone. I already have some third-party props to try. I just need to grind the nuts for them.>>Can that whining noise be easily eliminated? > > Maybe. Propeller tip vortexes and cavitation are making the noise. > The only way to reduce that is to reduce RPM's, which means you'll > need larger diameter props, or by clever prop design. Some > manufacturers offer low-noise props. I've never tried any, so I have > no clue if they actually work. > <https://airbuzz.one/why-i-dont-use-the-low-noise-propellers-anymore/> > > I couldn't find any for Walkera, just DJI: > <https://www.amazon.com/Anbee-Low-Noise-Propeller-Quick-Release-Platinum/dp/B07795ZT1P> > > Various low-noise propeller tests: > <https://www.youtube.com/results?search_query=low+noise+propeller> > >>I am assuming its origin is easy for some to guess. > > I never guess when I can also test. > 1. Take a vinyl hose and cram one end in your ear. Use the other end > to determine the source of the noise. I think you'll find that it > makes the most noise near the tips of the props. > 2. Remove the props from all the motors. Run the quadcopter without > the props. What's left is the contribution made by the brushless > motors, which I think you'll find isn't very much. > >>It uses brushless motors controlled by an "electronic speed control" >>(ESC). There is a large cap across each ESC supply plus and minus. I >>tried adding a 1000 �F low ESR capacitor on the battery input but that >>didn't help. > > Filtering the DC power inputs isn't going to do anything useful. >
Reply by ●December 26, 20182018-12-26
On 12/26/2018 02:30 AM, Klaus Kragelund wrote:> It sounds to me like it is switching noise from the motor drive, which causes movement of the motor windings > > It sounds to be a steady noise frequency which it won’t be if it is related to the blades > > No way to change it, except to change the motor control SW or filter the output to the motor to reduce the switching current ripple > > Cheers > > Klaus >I hear it now. Had to put on headphones, on laptop speakers I only hear the lower pitched blade noise
