bbiandov
Member
Hello,
For years I have assumed that what the MB sensors and monitor application report is actualy true - that is in terms of CPU and chasis fan RPM. The numbers that I have seen range from 3000 to 6500 RPM. Today however I was hooking up one of those DC brushless fans to AVR project that I am working on and my software was counting 150 RPM. I though I was wrong but then I hooked up the fan to my HP freq counter and what do you know - 300Hz come out of the RPM sensor wire (knowing a pusle is produced every time the field is switched, devide by 2 and you get RPM). So then I though the fan is bad, hooked up another one and got close numbers? What is going on? Am I seeing DA TRUTH or do those little fans actually go to 4000+ RPM and if yes, how can I explain my measurements? THanks
For years I have assumed that what the MB sensors and monitor application report is actualy true - that is in terms of CPU and chasis fan RPM. The numbers that I have seen range from 3000 to 6500 RPM. Today however I was hooking up one of those DC brushless fans to AVR project that I am working on and my software was counting 150 RPM. I though I was wrong but then I hooked up the fan to my HP freq counter and what do you know - 300Hz come out of the RPM sensor wire (knowing a pusle is produced every time the field is switched, devide by 2 and you get RPM). So then I though the fan is bad, hooked up another one and got close numbers? What is going on? Am I seeing DA TRUTH or do those little fans actually go to 4000+ RPM and if yes, how can I explain my measurements? THanks