__ Because it seems that these two posts are rather out-of-place in THAT thread, I've thus determined them both worthy of 'quoting'-forthward into THIS more suitably titled thread, for me (& whoever-else -[hopefully at-least 'Ducwiz']) to respond to.
____ I have no issues with any of Jim's post-wording,, other than he has left-out a useful comma, thus leaving his wording to seem as-if stating a 12v.system requires "larger gauge wires", (which at-least I-MYSELF happen to know he didn't actually mean).JimF wrote:I don't know Mototrans bikes but converting to 12-volts can be challenging. There are many threads in this forum about doing it with your existing alternator at one end of the spectrum and then at the other end of the spectrum there are aftermarket alternators that might get you a few extra watts of power for the change-over but they are expensive.
You'll have to remember that if you upgrade you have to change all your light bulbs, your horn, your regulator, your battery and possibly (probably) your ignition coil too.
Power is power, regardless of whether or not it comes in 6-volt or 12-volt flavor. What I am saying is that 50 watts in a 12-volt system is the same as 50 watts in a 6-volt system. There is absolutely no difference.
Some reasons to change are perhaps 6-volt consumables like light bulbs might only get harder and harder to find. In a 6-volt system the current (amperage) is doubled over that demanded by a equal 12-volt system requiring larger gauge wires, but wire is relatively cheap.
Six volt systems suffer more easily from power loss in poor (resistive) interconnections, but we should not have any poor connections anyway.
Jim
Many of us type of people already realize that the higher current-flow which SIX-volt systems have (for an equal amount of power @12v), should also have correspondingly HEAVIER-gauge wire to better cope with the DOUBLED current-flow. _ So 12v.systems are the systems which can more easily get-by with thinner gauged wiring.
____ I note that many writers & readers don't properly make use of commas, which makes it a bit more work for the reader to figure-out what the writer is actually meaning to convey, and thus possibly either lead-to misinterpretation, or just confusion (which the reader thus-then chooses to bypass & overlook).
__ I-MYSELF use a single comma for the std.normal reasons, and a double-comma to make-SURE that the reader doesn't overlook & ignore the camma's intended-purpose (whenever it's MOST needed). _ Comma-placement can really make a significant-difference in how a sentence is to be interpreted, so they ought-not be ignored (as too-many writers seem to do these-days) !
__ Also,, I-MYSELF also add 'hyphens' -(these marks: - ), which are intended to have the OPPOSITE-effect of a 'comma', which also helps to guide the reader away-from otherwise possible wording miss-association, (so-as to also help avoid confusion.)
StewartD wrote:Syruphead, Jim,
I converted my 450 Desmo to 12 volts and the 6 volt horn was left as it was. It really screamed but it lasted for the 10 years I rode that bike. I didn't use the horn that much though. I am doing the same on my Mach 1 that I have only just got back on the road. Will the life of the horn be shortened? Also I'm wondering if a relay for the horn button would be desirable.
On the issue of power from a 6 volt versus 12 volt conversion, I thought that current induced in a coil by a permanent magnet is determined by the strength of magnetic field and the number of coils of wire. I couldn't find anything on the net to confirm this. It is something I remember from long ago in Technical College.
Wikipedia has the following on voltage produced by a permanent magnet alternator:
"....Since the permanent magnet field is constant, the terminal voltage varies directly with the speed of the generator."
The standard Ducati regulator limits the voltage to 6 volts and a conversion such as mine, will limit the voltage to 12 volts, by using a zener diode.
So if current is the same and if the system voltage is changed from 6 volt to 12 volts, the power output is doubled. My experience with the 450 seemed to confirm this. I used higher wattage globes and never had problems with batteries going flat. The 450 was my only transport for much of the 10 years I had it, and it did lots of work at night.
This sounds too good to be true; am I missing something here?
Cheers,
Stewart
quote= StewartD...
" I converted my 450 Desmo to 12 volts and the 6 volt horn was left as it was.
I am doing the same on my Mach 1 that I have only just got back on the road. Will the life of the horn be shortened? "
____ Yes, but only if you keep your horn-button pressed too-long. _ If it doesn't get any chance to overheat,, then electrically, it should last about the same. _ Mechanically though, it's heavier blast-vibration may whack it out of life sooner,, (but as you've already proven for yourself, that's evidently not much of a concern).
" Also I'm wondering if a relay for the horn button would be desirable. "
____ When the contacts of the horn-button are not easily able to conduct ALL the current-demand of the horn, (which is more likely in 6v.systems), then a horn-relay is useful for getting a horn started & blasting louder. _ Since your 6v.horn will draw even MORE current with your 12v.system,, a horn-relay would thus-then be even more useful for allowing the extra current-draw to fully pass-through the horn, (instead of being somewhat curtailed by passing-through the 'bottle-neck' horn-button).
However, the extra efficiency which the relay-switch would provide, would likely not-only allow your 6v.horn to pass more power-juice,, but also, that possible extra current-flow would likely also help to cut-down your horn-life, as well.
So if you're content with your horn's operation as it is, then you might-as-well leave it's switch-setup as-is.
__ Many of those of us who have experienced how meagerly-faint our 6v.system horns can become (when any of it's circuit-parts have become weakened), ought-to consider a horn-relay setup (so that their horn can THEN get fed most-ALL of the available 6-volts).
Since so much of the voltage can become absorbed within the circuit-connections & rather thin-wiring (on 6v.models), it's too-bad that horn-manufacturers don't offer 4v.rated-horns for sale !
" On the issue of power from a 6 volt versus 12 volt conversion, I thought that current induced in a coil by a permanent magnet is determined by the strength of magnetic field and the number of coils of wire. "
____ That's pretty-much basically true...
__ To elaborate on that...
First I should point-out that I-myself am not one to 'dumb-down' aspects of such electrical-topics, so it's possible that anyone with mere BASIC-electrical training may think that they disagree with that which I claim, but any such possible disagreement has more to do with their learned basic misuse of related terminology,, (such as what the term 'voltage' is supposed to actually represent).
__ As I understand it, it's not the number of 'turns' so much as it is the 'length' of wire that can be fit (in any organized way) within the space where the magnetic-field/flux-strength is concentrated. _ Coils just do that job best.
__ The moving magnetic-field merely induces electrical 'tension' -(pressure, [which can be measured in 'voltage']), and 'current' can only come-into resulting-existence when a connected circuit allows that tension to bleed-down, (thus-then lowering the intensity of the built-up tension).
" Wikipedia has the following on voltage produced by a permanent magnet alternator:
____ That's also fairly-true but, I'd prefer it worded like: Since the magnetic-field is permanently-established as-is, any resulting 'tension' varies-accordingly with the speed of it's flux-lines passing through the stator-winding, - (as related to our DUCATI-alternators).Since the permanent magnet field is constant, the terminal voltage varies directly with the speed of the generator.
(They can justifiably get-by with stating "voltage" [rather than 'tension'] because, they had stated: "terminal voltage", which indicates measuring a reading-level, [which is only done in 'voltage' readings].)
" The standard Ducati regulator limits the voltage to 6 volts and a conversion such as mine, will limit the voltage to 12 volts, by using a zener diode. "
____ That's not an actually accurate statement... As the Ducati regulator-circuits, (both n-c & w-c types), don't directly-limit 'voltage' (to 6-volts), like a Zener-diode is able to-do. _ Rather, they regulate current-flow instead, which thus keeps voltage from being able to build-up. _ So unlike a Zener-diode voltage-regulator circuit, the Ducati-regulators actually depend on the battery to keep the system voltage-level down to the battery's set-level.
__ I, for-one, would like to have you explain pretty-much exactly how you have your particular 12v.system all set-up.
" So if current is the same and if the system voltage is changed from 6 volt to 12 volts, the power output is doubled. "
____ Well THAT statement, just as you happen to have it worded, would of-course indeed be true,, however, not only have you made your power-supplies '12-volts', you must've ALSO made your (rather constant) power-loads '12-volts', as well ! _ Right ?
And that being the case, the resulting 'current' is NOT "the same", and is consequently cut-down in-HALF,, so-thus, the 'power' (which is both 'voltage' & 'current' combined), remains the same !
__ So if what Jim had stated about this 'power' related matter, is that which you were not quite in concert with,, then now you should no-longer be overlooking the actual-fact.
" My experience with the 450 seemed to confirm this. I used higher wattage globes and never had problems with batteries going flat.
This sounds too good to be true; am I missing something here? "
____ Yes, I expect that's probably the case but, to figure-out exactly what was actually responsible for the particular high-function of your 12v.system, we need to know what-all rectification-component types you employed.
I'd much like to know, so I can then explain what processes your 12v.system was taking advantage of.
Duke-Cheers,
-Bob
