Evening star., 1953-02-23
Generator Regulator
Why's and Wherefors
Often Misunderstood
By Frederick c. Russell

S@9ANNee
car but it certainly can throw us
for a loop.
That's the average mechanics
opinion OF. the little device known
as the generator regulator.
Not only is there much misun-
derstanding Of the purpose and
the function of this relatively
modern control, but too often
the car owner encourages his re-
pair man to accuse the regulator
unjuStly. It looks so easy to
solve a lot of miscellaneous elec-
trical complaints by merely re-
placing the regulator.
So q fortune in discarded reg
ulators is the annual toll of a
new form Of waste. One owner
replaced three regulators before
1t was discovered that discharge
of the battery was due entirely
to q sub-hood light which failed
to go out when the hood was
closed.
A generator brush sticks and
some one says. Get a new regu-
lator."
Often owners tinker with the
old regulator only to ruin the
unit and throw every one way of
the course. One service manual
warns that if the metal cover
touches the terminals while re-
moving it, theren be a short"
and "finis" for the regulator.
Purpose Of Regulator.
While it has a lot Of wiring
and looks a bit wierd, the modern
regulator isn't so complicated IN
its main functions. Part Of it is
merely the cutout or circuit
breaker which used to be
mounted atop the generator.
This part Of the device merely
cuts out when the engine Is run
ming slowly or is off. and when
the battery might otherwise
discharge back into the gen.
orator to ruin it.
If the regulator is Of the sim
pier two-step type the second
portion is merely q control to
provide high generator output
when the battery is low and low
output when the battery Is up
to par. There is no actual in
crease in generator output be-
cause Of the regulator, q point
which should be carefully kept
In mind II the complaint u that
the battery runs down.
In q vibrating type OF regu-
lator the field circuit Of the gen.
orator is cut in and out with
the aid OF q resistance. This
provides q wide variation in
charging rates so as to meet q
wider variety Of operating con-
ditionS.
A feature Of this type Of regu-
lator is that there is limitation
of current output. Then there
is the combination type OF reg
ulator in which there are two
vibrating units. The two do not
operate simultaneously.
Tests of regulator operation
are made with q voltmeter and
an ammeter, and considerable
know-how. That is why 50.
many people are confused when
trying to change regulator ac-
ton or check it's misbehavior.
Gaps are sometimes set with
screws, sometimes with bending
tools. Contacts need cleaning.
This is done by filing the points
parallel with the length Of the
armature. Then there has to be
cleaning with carbon tetra-
chloride and drying with linen
tape.
When to Check.
There are just three abnormal
electrical conditions which JUS
tify looking into the action Of
the regulator:
# there Is no charging indi-
Gated by the ammeter, there may
be regulator failure, but here
again the trouble may be due to
. sticky generator brush holder.
q stuck brush, commutator
trouble or wiring breaks.
There may be continued high
charging when the battery shows
by constant need for water that
it Is being overcharged.
Finally there is the situation
where the charging rate and the
battery both are low.
How to Check.
Mechanics use a plain piece
of wire for preliminary checks.
First polarize the generator
match it with the battery by
running the wire from the regu-
lator posts marks Gen" and "B."
Touch just for an instant when
the engine is switched off. Now
if there is no charge or too low
charge, war mup the engine and
generator, and then with the
wire make temporary connec-
ton between the regulator body
and good ground.
If the regulator merely needs
q better ground this will show
it up should the charging rate
improve normally. But il you
wire from the "F" terminal to
q ground, and charging goes nor
NAL, the regulator really Is de-
fective.
Sometimes this and other tests
will fail to show improvement.
These mean that the trouble is
with the generator, the battery
or with the wiring.
In handling Q regulator make
sure you do not accidentally
bring the ''Bat" wire into contact
with the ground terminal. This
would damage the regulator.
Most regulators should be fas-
tened to the engine f1rewal be-
fore connections are made. To