Hot Tubes Igniters Low Coils Summary Disclaimer
Low Mags Buzz Coils High Mags Comments EXIT

If the ends of two wires forming part of an electric circuit are brought in contact, closing the circuit and then quickly separated, a bright spark will be produced as the contact is broken. This phenomenon underlies the operative principle of what is known as the MAKE and BREAK system of ignition. In old stationary gas engine practice, the simplest kind of igniter used city lighting direct current, with an incandescent lamp in series in order to prevent the current from being too strong.

Drawing of Gas Engine Igniter

An igniter is made up of a set of mechanical points, much like the points in early vintage automobiles, except they are located INSIDE the combustion chamber. One side is insulated, the other side is at frame ground and they are mounted to an assembly that PROTRUDES INTO the combustion chamber. A capacitor (condenser) is NOT used across these points because sparking across the points is WANTED, unlike in a car where the heat and metal consumption of sparks would wear away the surface of the points needlessly. When the igniter points "make" or close, a current will build up in an inductive coil that is in a series circuit. Then at the appropriate time, the points "break" and an inductive "kick" causes an arc to draw across the opening points. The gap opening is about 1/16". Even battery voltage itself will cause a small spark, but the more coil inductance that is in series with the points and battery, the hotter and bluer the arc created.


Hot Tubes Igniters Low Coils Summary Disclaimer
Low Mags Buzz Coils High Mags Comments EXIT

There's a WHOLE LOT more to this site so click and cruise around!
The Collector's Shelf!

SCRAM back to Harry's Home Page!

Published by Harry Matthews © 1995 - 2007. ALL RIGHTS RESERVED!

Valid XHTML 1.0 Transitional