JGJ <jgjacobs DeleteThis @NOSPAMShotmail.com> wrote:
> Hey Peter, I agree with you, so why doesn't someone explain to me how
> the charging system on a motorcyle work. I have a problem with a
> cx650e, it is not the battery.
What the heck, I'm in a writing kind of mood, so I might as
well. However, I have no knowledge of the CX650E, but I can describe
how the charging system in a modern (i.e. alternator, not generator)
Harley-Davidson works. Yes, I realize "modern Harley-Davidson" is an
oxymoron, but humor me anyway! The charging system of most alternator
motorcycles should be somewhat similar to this.
First, there is the alternator. This is constituted of both
the stator and rotor. The stator is basically a round core, which is
wrapped with many, many turns of coated copper wire. On a Harley,
this is located behind the compensator sprocket (basically, bolted to
the engine case, around the sprocket shaft). As the name implies, it
is "static". It does not turn. The two ends of the wire windings
exit the engine case, on the left side, all the way to the front.
The rotor is basically a steel shell, with magnets glued to
its inner circumference. It does rotate (once again, the name is not
only clever marketing <g>). It goes over the stator. On an H-D, it
is splined to match the sprocket shaft, and, as such, turns with the
engine itself.
The alternator, once again, as the name implies, produces AC
current. However, your battery, and pretty much every electrical
component of your motorcycle, require DC current. Therefore, a
rectifier is needed. What is called a "regulator" on most modern
motorcycles is actually a regulator-rectifier, and it has two jobs.
The first one is to rectify the AC current to DC. This is
easily accomplished with a simple diode bridge, but explaining this
would be a little too detailed for this post (it's easy, trust me!).
Its second job is to rectify the voltage to something that won't boil
or fry your battery or other components. On a H-D, it accomplishes
this by actually sending all excess voltage right back to ground.
This is why a good ground on the regulator is so important.
Therefore, the path of the current on your charging system is
as follows:
AC DC
Alternator --------> Regulator -------> Battery
There are usually some easy tests to determine the culprit in
the charging system. Realistically, these can usually be done in just
a few minutes. Here's how.
To test the alternator, unplug the regulator from the
alternator output. Make sure you're measuring AC voltage, and measure
the output at the plug, with the engine running. There should be a
spec in the service manual as to what output should be. For a modern
H-D, this is usually about 16-20 VAC per 1000RPM.
Shut the bike back off. Measure resistance between the two
pins on the stator plug. There should be continuity. If there isn't,
the winding is open, and the stator is shot. Also, measure the
resistance between both pins and the bike's ground. If there is
continuity to ground (or anything besides an open), the stator is
shorted to ground, and needs to be replaced. This is an important
test that most people forget to do. The problem is that the stator
can be grounded and appear to be producing the correct output.
However, as soon as you put a load on it, it'll drop back to squat.
And you'll have changed a regulator for nothing...Ahem.
If the stator windings test out OK, but the output is too low,
the rotor is probably to blame.
If the alternator tests out all good, test for continuity
between the regulator body and ground. There *should* be continuity.
Then, make sure the regulator output is properly connected to the
circuit breaker/battery. If it's connected properly, make sure you're
measuring DC voltage, measure at the battery, and fire up the bike
again. The voltage should climb, up to a reasonable value (no more
than 14.5-15VDC, check your manual for actual specs).
If the alternator output is good, the regulator is grounded
properly, and the connection back to the battery is good, but there is
no charging, the regulator is to blame.
As mentionned, all the above is for a H-D, but most of it
should apply to other alternator systems. This also assumes a
two-phase alternator, the three-phase is almost identical, except with
an extra stator winding, and regulator that takes three inputs.
As usual, use at your own risk, YMMV, IMHO, etc...
Phil
--
AH#61 Wolf#14 BS#89 bus#1 CCB#1 SENS philb DeleteThis @total.net
<a style='text-decoration: underline;' href="http://ah61.com" target="_blank">http://ah61.com</a> EKIII rides with me. <a style='text-decoration: underline;' href="http://eddiekieger.com" target="_blank">http://eddiekieger.com</a>
"And even though I've tried my best, I still can't find no happiness" - P. Tosh<!-- ~MESSAGE_AFTER~ -->
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