Mister_T,
An excited-field alternator is regulated just as Skip said.
The more powerful the magnetic field is in the alternator,
the more electrical current will be generated. More
electrical current is (generally) created at higher
alternator rpms. With the KLR's permanent magnet setup,
the electrical output can't be controlled by varying the
alternator's magnetic strength. The only solution that I
have found (in motorcycles) is to "bleed off" the excess
current by shorting it to ground & converting this excess
energy to heat. This is done by using special diodes that
only pass current to ground when a preset level has been
reached, kind of like a water pressure relief valve on a
water heater. This type of "voltage regulation" can fail
if the diodes always pass all current to ground or if the
diodes are always "open" (similar to a blown fuse). If the
regulator over-heats beyond it's design limits, one of these
failures will eventually occur, rendering your KLR with a
total-loss electrical system, or an unregulated system that
blows bulbs & cooks batteries.
The primary advantages to the permanent magnet setup is
simpler construction, increased reliability, no brushes to
wear out and lower cost.
The KLR's charging system is rated at 14 amps @ 8000 rpm with
14 volts, yielding a maximum of 196 watts maximum output
(10.5 amps, 14 volts @ 8k for the KLR600). You could use the
regulator as a wet socks dryer, but I wouldn't recommend it.
If Skip wants to contradict me, I hope he's in the right
"mode" & doesn't dig himself into too deep a hole (g).
I hope this makes some sense.
Professor A9 Federal Way, Wa. [USA]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--- Ted Palmer wrote:
> Fine for an alternator that actually has a controllable
> field coil. When you have an alternator that uses
> permanent magnets, how do you control it?
>
> Mister_T>
~~~~~~~~~~~~~~~
Skip Faulkner wrote:
> [...]
> > Jim, I believe you`re confusing the regulator with
> > something else. The old point regulators ( like on my
> > 72` Suburban) and many older aircraft work by
> > controlling the field current to the alternator (to a
> > preset limit) in effect taking the alternator off-line,
> > thousands of times a minute.
> > [...]