Page 2 of 2
Posted: Thu Nov 29, 2007 2:39 pm
by Paradigm
cipher_nemo,
I haven't seen a DC fan that can't be PWM controlled. It's just a matter of frequency. Get it well over 20KHz and you won't have any possibility of a human hearing it. Of course there are a few other tricks to help too, but I wouldn't want to give away all of our secrets
Posted: Thu Nov 29, 2007 3:02 pm
by NeilF
Paradigm wrote:No, you're not hearing things. Our previous motor controller did use pulse control, however it did it at a much slower rate. The result is that there are artifacts within the audible range. On some fans, you really couldn't hear it. On others, you definitely could.
If we do go pulse control on this next one, it will be in the order of 1000 times faster. This would push any artifacts, or harmonics there of, way out of the realm of human hearing.
The one benefit of pulse (on your previous units) was the 'strobe' effect.
On my unit my fans appear to either be still or turning VERY slowly... Looks VERY cool!
Posted: Tue Apr 22, 2008 5:15 pm
by chunkywolf
Is there any estimate of when this will be coming out?
Posted: Tue Apr 22, 2008 8:57 pm
by Henry
The prototype PCB arrived today, and code work begins tomorrow, so if all goes well there might be pics by the end of the week.