Were resistor plugs around when the points saws were made?
I thought resistor plugs were something to do with radio interference and wondered what that had to do with chainsaws.
Resistor plugs were designed in the 40s, to cut down on radio interference. Back then, all ignition wire was solid metal. In later years, the manufacturers designed resistance wire, made from carbon impregnated cloth. The wire, was designed to have approximately the same resistance, approximately 5,000 ohms, as the resistor in the plug, and thus eliminating the need for the extra cost of building a special spark plug.
I was taught that the ignition resistance had virtually no effect on the operation of the ignition system.
You can calculate the voltage needed for electricity to jump across a spark gap with a simple formula: voltage equals the air gap length in centimeters times 30,000.
I don't have my calculator handy, but assuming the gap is .035 in:
0 .035 in x 2.54 cm/in x 30,000 = required voltage to fire the plug = 2,667 volts
I could not find any information regarding how much the resistance in the plug or the wire changes the voltage required to fire the plug.
Whether it is a point triggered standard ignition or an electronic ignition, would not change the voltage. The difference with an electronic ignition is, that the higher secondary voltage of the electronic ignition, reduces the total current draw in the system.
In automotive use 12v system..... normal draw equals approximately 2 amps.
electronic system, primary voltage 400 v, and current drain equals approx .1 amp
The lower amount of current in the electronic, CD, system, is why the plugs live longer.
Been busy unbagging parts...
