Not ALL brushless DC fans can be speed controlled via PWM, but the presence of a tach lead is a good indicator that a fan can use PWM. Sometime early last year I grabbed a fan at random from my parts bin (junk drawer) to test a PWM output for a LEGO robot and thought the output channel was not working (it was either on or off, no speed control). But it turned out that BLDC fan just was not compatible with PWM.
On Tue, Feb 2, 2021 at 2:17 PM Carl Nobile via TriEmbed < [email protected]> wrote: > Jon, that all sounds very logical, and had I thought about it a little > longer I would have realized that it wasn't a brushed motor, so I will > withdraw my comment. > > All brushless DC motors are actually AC synchronous motors with > electronics between the power and the motor that converts the DC into AC. > It looks like Pete's motor is 5V DC, not 12V DC, however. > > On Tue, Feb 2, 2021 at 2:01 PM Jon Wolfe via TriEmbed < > [email protected]> wrote: > >> yes, besides the electrical, and also audible noise, a brushed motor >> would wear out its brushes. any motor that's intended to be on most or much >> of the time, and have a long maintenance free service life, is going to be >> brushless. Most fans used in pcs are going to be brushless running off 12v. >> You can pwm the power supply to do speed control, its done all the time. >> >> On February 2, 2021 1:43:45 PM John Vaughters via TriEmbed < >> [email protected]> wrote: >> >> Computer fans are almost always brush-less, actually never seen a brushed >>> one. Because the electrical noise is too high. She 3 pin motors are simply >>> two power pins plus one tachometer pin, which you generally only want to >>> determine if the fan is failing. I could be wrong about this part, but I >>> expect that they are single voltage and reducing the voltage may or may not >>> affect the speed much and possibly could damage the fan over long use. >>> However, I seem to remember some schemes to make 3 wire fans speed >>> controlled. it's worth a look online I suppose. >>> >>> John Vaughters >>> >>> >>> >>> >>> _______________________________________________ >>> Triangle, NC Embedded Computing mailing list >>> >>> To post message: [email protected] >>> List info: >>> http://mail.triembed.org/mailman/listinfo/triembed_triembed.org >>> TriEmbed web site: http://TriEmbed.org >>> To unsubscribe, click link and send a blank message: mailto: >>> [email protected]?subject=unsubscribe >>> >> >> _______________________________________________ >> Triangle, NC Embedded Computing mailing list >> >> To post message: [email protected] >> List info: >> http://mail.triembed.org/mailman/listinfo/triembed_triembed.org >> TriEmbed web site: http://TriEmbed.org >> To unsubscribe, click link and send a blank message: mailto: >> [email protected]?subject=unsubscribe >> >> > > -- > > ------------------------------------------------------------------------------- > Carl J. Nobile (Software Engineer) > [email protected] > > ------------------------------------------------------------------------------- > _______________________________________________ > Triangle, NC Embedded Computing mailing list > > To post message: [email protected] > List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org > TriEmbed web site: http://TriEmbed.org > To unsubscribe, click link and send a blank message: mailto: > [email protected]?subject=unsubscribe > > -- [image: photo] *Shane D Trent* Patent Agent 919-348-0061 | [email protected] ShaneTrent.com | Skype: skype:shane.trent1 <#SignatureSanitizer_SafeHtmlFilter_> Raleigh, North Carolina <http://www.linkedin.com/in/shanetrent> <http://twitter.com/sdtrent> Create your own email signature <https://www.wisestamp.com/create-own-signature/?utm_source=promotion&utm_medium=signature&utm_campaign=create_your_own&srcid=>
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