This section will focus on the building of the ignition circuit. This circuit can be found at the DIY Gas Turbine Forum on Yahoo Groups. There is a link from the main Jet Bike page to the groups. The ignition circuit is based on the 555 Timer IC, available anywhere electronics are sold. I bought my parts from Tanner electronics here locally. The circuit only serves to provide a pulse to an automotive ignition coil (or in my case a motorcycle coil) so that it can produce the high voltages needed to arc a spark plug

The completed circuit board for the ignition

I won't bore you to death with photos of me soldering parts, instead I will just show you the finished board. This is a breadboard, and unlike a normal circuit board with the etched wires on it, this one just has holes. The connections are made with jumper wires. It is a useful technique for prototyping and one off projects. You can see the 555 Timer in roughly the center of the board. At the top are the 2 transistors and large output capacitor. The rest of the circuit is made up of small capacitors and resistors to provide the timing for the circuit.

The power jack that will allow connection to the bike

You can see the board here soldered to the jack that was installed in the enclosure. The jack will allow the unit to be unplugged for easy servicing later.

The circuit board mounted securely in an enclosure

Here is the completed board mounted in the enclosure. The components are down in the box.

The completed ignition unit

With the lid attached it is a compact unit that should stand up to a bit of jostling around on the bike.

Testing the ignition unit

Here is the IPU (ignition pulse unit) connected to the battery and coil for testing. The wiring harness has four wires, red, black, orange, and brown. The red is battery positive, black is battery negative, orange is coil hot, and brown is coil ground. The spark plug makes a very noticeable sound when hooked up. It even tries to spark right into the concrete with no ground attached to it! There is a very noticeable arc and a loud sharp crack when it fires. Success by my standards. It works, but I did want something with a more constant spark. I will try other designs later if this one proves to not work very well, but for now it looks like it will do the trick.

The ignition unit with the schematic from the Yahoo DIY gas turbine group

Here is the completed IPU with the schematic I downloaded. I just took the schematic to Tanner's and they got everything I needed. Took me about an hour to solder everything together. Will it ignite an afterburner though?

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