[Milsurplus] Re: Arc-5 not so) Mobile

[J Forster]

Try some simple math:

I = C  dV/dT  so dV = I * dT /C

Assume the dyno draws 25A for 1/2 second while spinning up.

two 60,000 MFD = 0.12 F

dV = 25 * 0.5 / 0.12 = 12.5 / 0.12  or roughly 100 Volt drop on a 24 V supply.  No wonder at all !!

Best,
-John



Falls, Jim wrote:

> Thanks, Dave and all - Maybe I've been doing this wrong........I used a pair of 60,000 mF in PARALLEL w/a 12V/15A supply and it still kicked it OFF (little dyno pulls 3A loaded; spikes to 25A momentarily [0.5 sec] when winding up.). Maybe the caps are shot. Maybe I really need a 2F cap from a Low Rider...Cheapest stripped version I've found is around $60; bells and whistles is easily twice that. I can cobble together around 250,000 mF using all my "big cans", but will this even be worth the work?
>
> Jim Falls
> KG6FWT
> Eureka, CA
>
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