LinkMeter blower???

[Jim Muoio]

Ok, quick trip to Radio Shack to get an assortment of electrolytic caps and stuck another 22uf 25v as Bryan suggested and paid attention to polarity as Ralph suggested and the fan kicked in at around 5%. Played with it a little and was happy with that. The fan does run a bit faster so I will need to throttle down on the max percentage.I also played with adding up to 80 or so uf and lower percentage response improved but the fan was humming at those lower rates. I will probably pull the 22uf out and replace with a 47. Does the voltage matter as I have in the assortment a 47uf 35V not 25v??

Bryan,

By the way this thing is awesome. I have already begun to dive into the code as well to see what I see as I was a software engineer in my previous life and still play around with C# for my robot when it is not in pieces adding the next wiz bang sensor. Have not done much arduino and only pretend to know linux but I was able to pull from GIT and partially build linkmeter and openwrt. Can I ask you what your development platform is or are you one of those emacs or vi guys who I just can't compete with!! Are you using Ubunutu or what?

 

[RalphTrimble]

any voltage at or higher than the original voltage will work for a capacitor...
Glad you got it working better. If the fan kicks in at 5% now that seems pretty good? I think it might be a good idea to set the min fan speed to match whatever speed the fan kicks in so the calculations are most accurate? (Bryan?) Perfection will come with trial and error....

 

[Bryan Mayland]

What Ralph said is right, any voltage higher than 25V is fine on the caps. If you add too much capacitance then the fan will just run balls out regardless of what percent it is supposed to run at so keep that in mind. The 22uF was worked out with trial and error for the suggested fan and measuring the RMS voltage that it produced.

I do most of my development on my Ubuntu "media center pc" with vi and screen. The rest is done on the RaspberryPi itself with just vi. The HeaterMeter part I do in Visual Studio with the awesome Visual Micro Arduino plugin which makes me incredibly productive. I am a C# and Delphi developer with a 20+ year background in C++. My dad was an electronics officer on a P-3 sub hunter for the Navy so I grew up with a bit of a fascination with circuits but no real understanding of them. It is really a golden age of learning now, with the amount of power you can get in a microcontroller for just a few bucks. It really just came down to the basic rule that if you want to learn something, start a project you are really interested in and go for it.