>There's nothing exotic about it. The diesel and alternator are bolted
>to a pair of steel rails made from a highway sign post. The rails are
>bolted to a wooden base plate. A short (about 30") serpentine belt
>wraps around the flywheel and the 6 ribbed pulley on the alternator.
>That's it.
>If you use a operative 1 wire alternator it has all the regulation
>necessary to control the charge on the battery. Since I buy junk
>alternators, that circuitry is usually broken. Sometimes I can salvage
>the 6 diode bridge. If not I furnish an external one.
A true one wire alternator isn't a good choice because the output voltage is set
high
to compensate for the inadequate wiring the mfrs assume will be used. I've yet
to
measure one that output less than 14.1 volts.
>I use a DC power supply to excite the armature and control the output
>voltage with the alternator current. Right now the output goes to a
>Blue Sky charge controller and from there to my 10 battery bank.
>I'm working on a controller circuit that monitors voltage, current to
>the battery and temperature at the post. Rather than using an exotic
>MOSFET circuit to chop up the output I'll use a simple low current
>circuit to control the armature current (typically about 1 amp). Then
>engine runs at about a constant 1000 rpm.
My Rev 1.0 digital controller for my Cordless Battery Charger goes one step
better.
It has a mosfet driven by the PWM output of the PIC (yaaa, exotic, one
transistor and
one PCB trace :-) to drive the field but the main regulation is done via a
stepping
motor on the throttle. I vary the engine speed to regulate charge rate. I have
to
vary the field some too, to account for the loss of torque at lower engine
speeds but
I think I can work around that in Rev 2. The advantage of varying the engine
speed
is, of course, lower fuel consumption and a LOT less noise.
Most gas engines achieve the best BSFC with the throttle wide open and operated
at
MBTP, something my controller achieves whenever possible. With your diesel, all
you'd have to do is regulate the fuel and field to operate at the most efficient
point. Also, for Rev 2.0 I'm going to use an RC servo on the throttle instead
of a
homemade one. They're so cheap and reliable that it doesn't make sense to go any
other way.
John
---
John De Armond
See my website for my current email address
http://www.neon-john.com
Cleveland, Occupied TN
Remember, Amateurs built the Ark. Professionals built the Titanic.
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>to a pair of steel rails made from a highway sign post. The rails are
>bolted to a wooden base plate. A short (about 30") serpentine belt
>wraps around the flywheel and the 6 ribbed pulley on the alternator.
>That's it.
>If you use a operative 1 wire alternator it has all the regulation
>necessary to control the charge on the battery. Since I buy junk
>alternators, that circuitry is usually broken. Sometimes I can salvage
>the 6 diode bridge. If not I furnish an external one.