CDI Ignition Box??

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jmadden91
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Thu Nov 05, 2009 9:22 am

Hey guys im completely in the dark here, just wondering if something like this

Image

would work in a similar way to launch potato's ignition circuit? Or could be modified to do so?

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jrrdw
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Thu Nov 05, 2009 9:38 am

You will need a triggering device and a power supply. Probly more trouble then it's worth.
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jmadden91
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Thu Nov 05, 2009 9:41 am

So your not just talking a 12v battery and a momentary switch?
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Technician1002
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Thu Nov 05, 2009 12:07 pm

CDI ignition modules do not contain the high voltage (spark voltage) side of the circuit. They contain an inverter and a SCR for the switch to power the Primary of an ignition coil.

A standard ignition works by turning on 12 volts to the coil to get a current flowing. This is the Dwell portion where the points are closed. When the points open the current that was flowing through the points now flow into the condenser. The condenser quickly charges to a high voltage and slows the current in the coil. The rapid magnetic field change makes the high voltage output to fire the plug. (yes it makes the spark when the power is shut off)

CDI simply charges a cap to that high voltage and dumps it into the coil (usualy about 300V) and the rapid rise in current creates the high voltage for the spark. CDI sparks when the power is switched on. CDI stands for Capacitive Discharge Ignition. The module in the photo above is simply missing the coil.

MSD is multi spark ignition, which fires a quick sequence of capacitors to make a short burst of sparks.
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jrrdw
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Thu Nov 05, 2009 2:47 pm

Stungun is the easy way to go. :wink:
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jmadden91
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Thu Nov 05, 2009 7:11 pm

Awesome thanks for the help guys, knowledgeable as ever Tech. Stunguns are out cause im in Aus jrrdw. Ill just stick to the humble electronic bbq igniter. Thanks again guys
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