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Japanese Bikes / Re: Honda cb175k6, 1972 re-build
« on: September 25, 2020, 10:44:04 AM »
That sounds like late 6 volt Lucas systems fitted to British bikes with alternators. The alternator can only produce alternating current (AC) by design and batteries must have direct current (DC) to charge so the designers make the alternator feed all the rest of the electrical system via a rectifier which turns AC into DC. The variation in output as alternator speed rises isn't very great on a 6v system so the bulbs and horn can cope with the small potential over-voltage. This is doubled in a 12 v system so more likely to blow bulbs and boil batteries, therefore the need for a regulator to prevent over charging. Designers could use a CVC (Compensated voltage control) box as on cars of the era but these were better suited to dynamo systems as well as expensive and don't really like being in the hostile environment of a motorcycle! Semiconductor electronics had yet to arrive of course. So they did it on the cheap by balancing load to supply and losing the excess current as heat via the battery and bulbs.
Warning! Some parts of this explanation have been simplified!
REgards, Mark
Warning! Some parts of this explanation have been simplified!
REgards, Mark