Here's a mystery for you who are electronically inclined. You know who you are
I have recently resumed fighting the alternator whine war. I have identified the whine in the intecom as definitely coming from the alternator. As per Rotax recommendation, Van's included a 22,000 mfd capacitor in the fuse panel in parellel with the power bus to smooth the noisey output from the regulator/rectifier. I reasoned that if extra capacitance (another 22,000mfd cap) was installed right at the regulator output forward of the firewall the noise would be killed before it entered the avionics bay. I checked with Van's tech support and they didn't see any problems with this idea, in fact they asked me to report back results.
So I ordered and installed the extra capacitor, right at the firewall, with nice short leads. Negative side grounded to the firewall mounting bolt. Very proud of myself for the really neat and professional looking installation! Problem is, now there is NO alternator output!
Was aghast thinking I had ruined the regulator or worse, the alternator! Unhooked the new capacitor and operation returned to normal. Phew!
So, can anyone think of why the regulator doesn't like 44,000mfd instead of 22,000mfd across its ouput? I'm stumped. And oh yes, I'd still like to get rid of the whine before I have to listen to it all the way to Oshkosh!
BTW, I called Dean at Lockwood and he has no idea why this would happen either.
So I ordered and installed the extra capacitor, right at the firewall, with nice short leads. Negative side grounded to the firewall mounting bolt. Very proud of myself for the really neat and professional looking installation! Problem is, now there is NO alternator output!
So, can anyone think of why the regulator doesn't like 44,000mfd instead of 22,000mfd across its ouput? I'm stumped. And oh yes, I'd still like to get rid of the whine before I have to listen to it all the way to Oshkosh!
BTW, I called Dean at Lockwood and he has no idea why this would happen either.
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