" Hows this: "
____ That's pretty-much the best rect.block you'll find at any price !
You'll possibly find a use for as many as 3 of those bridge-units.
" While I'm ordering parts, what size capacitor do I need? "
____ At that same w.site, you could get these...
http://www.allelectronics.com/make-a-st ... TOR/1.html ;
http://www.allelectronics.com/make-a-st ... TOR/1.html ,, and as CHEAPly-priced as they are, I suggest that you ought to purchase at-least one of each (just in case you can't get one that's better suited) ! _ Cuz at just "$2.50" & "$4.75", they are relatively great bargains !
Although however, neither of those two cap.units has the best suited specs, which ought to be more like 6k.uf with nearer to 25working-DC.volts, (rather than their stated 13k.uf @ 15v, & 33k.uf @ 50v).
__ Normally it would be reasoned that the larger (upwards towards 75k.uf), the cap.size, the better it would be more like a storage-battery. _ However after a cap.unit that large becomes discharged, you'd then have to kick-over the motor a number of times (with the ign.switch not yet turned-on), before the capacitor would get a chance to build-up it's stored alt.power-pulses and become charged-up enough to allow the ign.coil to become subjected to sufficient voltage, (when the ign.switch is then-next turned-on).
Conversely on the other-hand,, a cap.size that's too small won't be able to store-up all the pulses of alt.power-juice that the alt.circuit provides. _ But somewhere between 3k & 8k.uf ought to be about the best compromise, so as to fully supplement the 'timed' power-pulse well enough for your ign.system, (without also competing against the ign.coil for alt.power-juice supply, [just during start-up] ).
For twin-cylinder Brit.bikes, Lucas came-up with a cap.size of 6400uf, but whether or not they had actually done their homework-figuring to the Nth-degree, others still reason that at least 15k-uf is 'better'.
But to be BEST, ya need TWO capacitors of DIFFERENT cap.sizes ! _ (Which is what I always chose to do when making-up my-own battery-eliminator circuit... usually using one 3k-uf & one 8k-uf, with 15 to 30 working-volts.) _ Here's a better than suitable 8k-uf cap.unit for about half-price...
http://www.ebay.com/itm/Cornell-Dubilie ... 0281489660__ Here are places with a wider-selection, but at full-retail prices...
http://www.tedss.com/Capacitors/Browse/ ... uter-grade http://compare.ebay.com/like/1406136123 ... s&var=sbar Whereas THIS-place has fairly FAIR-retail prices...
http://www.mouser.com/Search/Refine.aspx?Keyword=8000UF So now you ought-to realize how fairly-low the prices are for those two cap.sizes at that place which YOU had found.
____ Please note that I've finally fully-finished my (DCT-Bob)post on the previous-page !
Dukaddy-DUKEs,
-Bob