chill wrote: > I was interested to see how to control a simple fan in software. To > date my RPi4 seems to run comfortably cooler than the throttling > temperature, but having developed a way to mount a fan in my 'stack' > inside my amplifier, I was keen to see if I could leave it permanently > connected but only have it running when needed. > > My simple 2-wire fan draws about 45mA on 3.3V, which is too much to > drive directly from a GPIO pin. So I wired up a little transistor to > switch the GND side of the fan according to the state of a GPIO pin. I > made it so that it simply plugs into the existing fan wiring. > > [image: > http://www.cjh.me.uk/MyPhotobucket/cache/DIYHifi/Transistor%20wiring_480.jpg] > > [image: > http://www.cjh.me.uk/MyPhotobucket/cache/DIYHifi/Transistor%20fan%20control_480.jpg] > > Then I made a script to turn the fan on and off according to > temperature. I set the 'off' temperature one degree below the 'on' > temperature to reduce the frequency that it turns on and off. > > Here's the result from an idling pCP (no LMS, no Squeezelite) in the > open air. When running at 3.3V the fan takes about 5 minutes to pull > the temperature down from a resting 56 degrees to the 40 degrees that I > set, then it sits at that temperature, with the fan coming on and going > off as necessary. It struggles to get much below that. Running on 5V > it cools faster and lower, but it becomes audible. > > [image: > http://www.cjh.me.uk/MyPhotobucket/cache/DIYHifi/Fan%20with%20GPIO%20control_480.jpg]
Nice Job ! *Players:* SliMP3,Squeezebox3 x3,Receiver,SqueezeLite-X,PiCorePlayer x3 *Server:* LMS Version: Latest Nightly on Centos 7.6 VM on ESXi 6.5.0U3 on Dell T320 *Plugins:* AutoRescan/BBCiPlayer/PowerSave/PowerSwitchIII/Squeezecloud/Spotty/Player Groups *Remotes:* iPeng9/Orangesqueeze/PC/Jivelite/SqueezeLite-X *Music:* 522GB,1.5K albums with 25K songs by 5K artists mostly FLACs *Want a webapp ?* See http://forums.slimdevices.com/showthread.php?104305-Webapp-for-LMS ------------------------------------------------------------------------ Jeff07971's Profile: http://forums.slimdevices.com/member.php?userid=49290 View this thread: http://forums.slimdevices.com/showthread.php?t=110690 _______________________________________________ discuss mailing list discuss@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/discuss
