Zeitgeist wrote: > Not sure why tantalum was chosen over electrolytics, but here's my source > article: >
IIRC, tantalum caps have a wider temperature range and narrower tolerances. (Electrolytics are usually no better than +/- 10%, with +20/-10% not being uncommon.) Electrolytics also have a limited life span -- eventually they dry out. Finally, they're less compact. All Electronics has tantalums, but I think they have a minimum order: http://www.allelectronics.com/cgi-bin/category/140800/Tantalum.html Digi-Key has been aggressively removing items from their catalog that contain heavy metals and toxic substances, so that's probably why you can't find them there. There's a big push in the electronics industry to use less toxic materials, especially in Europe, where companies are required to take devices back for recycling. > http://www.benplace.com/vanagon_intermittent_syndrome.htm > It looks like they're using the capacitor as a filter to shunt noise to ground. The value is probably non-critical. I'm not sure why they don't want you to use an electrolytic. This seems like a classic application for one. It may be the engine compartment is too hot for them. I always kind of suspected the underlying problem was that the mechanical AFMs would get worn spots where the signal would get "noisy," kind of like a scratchy volume control. I never had a van with "Vanagon syndrome," or I'd have attached an oscilloscope and found out.
