Tuesday, January 12, 2010

The Smell of Ozone

As I mentioned in my previous post, I tried out several different spark ignition systems as potential replacements for the C&H CDI box I have been using.

From left to right are a spare coil for my '76 Ford Pickup, a Tecumseh small engine coil, an AC Delco "coil near plug" module, and the RCEXL CDI System. The first three are all designed to be used in inductive discharge, or Kettering, ignitions systems. Most of the testing I did was at 100 sparks per second. I did not measure spark energy or current as I don't have the equipment necessary.

Ford Can Coil

This is a fairly standard coil used on almost any older car with a distributor and points setup. One can get a coil like this at any automotive parts store by asking for a coil for a random car built before 1975 or so. It is easy to drive with almost any transistor per advice from Thomas McNeill. I actually used a power MOSFET that I have been using to control solenoid valves. I tried this coil while I was waiting for others to ship because I had it already on the shelf. I wouldn't recommend using it otherwise. It generated the weakest spark at the lowest cost of the four options.

Tecumseh Coil

This coil was tested by the folks over at the Rocket Work Bench website (PN# 30560A). It was inexpensive and gave fairly good results so I thought I'd give it a try. As was noted before, it gets fairly warm, especially running at 100 sparks/second. That is not really surprising as it was probably designed for around 3000 RPM or 25 sparks/second. It does seem to produce a fairly energetic spark and is triggered the same as the can coils.

I'm going to make this a multi-parter because its late and I'm being paged.

To be continued ...

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