AUTO SPARKERS

By Staff
Published on November 1, 1978

641 Park Avenue, N. Mankato, Minnesota 56601

I am a partner with John P. Hiniker in restoring and saving old
tractors and gas engines. John sells decals for some tractors and
engines. We have 40 tractors and 30 gas engines, plus several
separators, binders, and equipment of bygone days. Our biggest
tractor is a 35.-70 Minneapolis Cross mount weighing 12 tons. The
biggest engine is a 16 HP Eagle single cylinder. John can take a
piece of pure junk and make it look and run like it had never been
used!

My wife, Lorraine, boys, Nick and Chris, and girls, Cathy and
Liz, also take a great interest in these old machines. We all have
been reading G.E.M. from the start.

A few years ago Glenn Karch, R.R. 2, Haulstadt, Indiana, wanted
information on auto sparkers. I have a book called ‘The
Practical Gas Engineer’ that shows and tells about them. This
was written June 1, 1901.

An auto sparker is really a D.C. (direct current)
dynamo…something like a modern day generator with a governor to
control the speed. The dynamo depends on its fields from which its
current is generated. The rapidly revolving armature between the
wound fields of the dynamo excites them and a current is generated.
A magneto that we are familiar with depends on permanent magnets
for the generating of its current. The armature revolving rapidly
between permanent magnets generates a current.

The dynamo, or auto sparker, is a small generator constructed on
principles similar to a dynamo or generator used for electric
lighting purposes – a miniature machine with current capacity only
sufficient to produce a good strong igniting spark at all times.
Storage and other batteries are used in connection with some of
these dynamos for starting purposes. They require a certain speed
before they will generate an igniting current. This speed must not
vary to any great extent. If much below the normal, the current
will be too weak for igniting purposes. If speed runs above normal,
there is danger of burning out the field winding. Therefore, if the
dynamo were set at a speed to generate an igniting current, when
the engine is turned over by hand, it would quickly burn out its
field coils under full speed of engine, unless some governing
device were used. Consequently, the engine is started from a
battery current, and when the dynamo has gained a generating speed
which is attained at full speed of the engine, its current is
switched onto the engine and the battery current is cut out.

Another thing that might be of interest to readers is how to
test an auto sparker. All old machines, large or small, should be
taken apart, cleaned and checked and overhauled first.

Then the current from a dynamo or auto sparker igniter is
tested, while the dynamo is running at its rated speed by taking a
piece of wire about 2 feet long with insulation stripped off both
ends. Place one end onto one of the binding posts of the machine
and snap the other end off the other binding post. This will
produce a faint spark if a current is generating. By placing a
spark coil in the circuit-that is, by taking two wires as above
described and connecting one end of each to a binding post on the
coil and using the other ends to make and break the current on the
dynamo binding post – you get the full benefit of the current and
can judge of the igniting qualities by the size and color of the
spark.

The fields of a dynamo should not become overheated, but should
remain cool. The bearings should be oiled properly and the brushes
and commutator should have regular attention. It should be kept
absolutely clean.

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