Subject: Generator 5 of 7



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(3543)   Sun 21 Jul 91 23:28                             
By: Don Kulha
To: All

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Use heavy bolts with lock washers to secure everything to the base.  
Be sure to get the alternator turning in the right direction.  
Electrically 
it makes no difference, but the alternator's fan is designed to suck 
air from the back of the alternator and to exhaust this air in front 
around the pulley.  If the alternator's fan is running backwards 
then the alternator will overheat when heavily loaded.

Use large wire to hook up the output of the alternator.  Something 
between 6 gauge and 2 gauge is fine, depending on the length of the 
runs.  Locate the motor/alternator as close as possible the 
batteries.  
This keeps power loss in the wiring to a minimum.  Consult the Basic 
Electricity article in this issue for details.

Control Systems
The first motorized charger we built worked fine, but we had 
problems 
controlling it.  We were using a stock car voltage regulator.  It 
wanted to charge the batteries far too quickly; in many attempts 
the large load stalled the motor.  We have experimented with many 
forms of control for the alternator and have finally arrived at 
several 
which work well.

All alternator controls work by limiting the amount of power 
supplied 
to the alternator's rotating magnetic field.  All alternator control 
starts with controlling the field's energy.

Car Voltage Regulators
Car voltage regulators will not work well in deep cycle 
applications.  
The regulator makes its decisions based only on the system's 
voltage.  
This is fine with the average car battery which is cycled to less 
than 1% of its capacity before being refilled.  The deep cycle 
battery, 
however, is almost empty when it is recharged.  The car voltage 
regulator 
attempts to instantly bring the system's voltage to about 14 volts.  
A 12 volt deep cycle lead-acid battery will not reach a voltage of 
14 volts until it is almost filled.  The net result is that the car 
regulator dumps the entire output of the alternator into the 
batteries 
until they are full.  This is most always too much energy too fast 
for a fully discharged battery.

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