Buzz Coil Condenser/capacitor

[Anonymous]

Here are a couple more simulations, using a transformer rather than a coil. The output graph in each case represents the output of the secondary. The inductance of the primary is 100µH as before, for the secondary 10mH, on the naive basis that the turns ratio is 100:1, and the mutual inductance is 600µH, implying a coupling coefficient of 0.6. Here's the picture for the basic transformer:

and for the capacitor with transformer:

No great surprises, bigger voltages all round! I'm not sure why the oscillation in the case with the capacitor/transformer appears to be truncated for a short period after the first oscillation. I suspect a limitation of the simulation. In the real world both the diode and transistor would have let out the magic smoke long before. It seems pointless trying to simulate a spark gap, so I'm not going to try. Instead onto the real world and I'll try some tests with my experimental ignition coil. I might get time this weekend as it looks like the weather is going to degenerate into showers, so no flying, , but that does mean more time for playing at engineering .

Regards,

Andrew

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Andrew Johnston on 02/08/2012 22:41:28:It seems pointless trying to simulate a spark gap, so I'm not going to try.

It is difficult to simulate the spark gap because of the negative resistance when the arc first starts but it is perhaps the most important component. After all, the object of the excersise is to put energy into the spark in order to ignite the mixture.

Some real world waveforms with a simplified explanation can be seen here

Have fun and keep your fingers away from the high voltages

Russell

[Martin WParticipant @martinw]

Hi

Russel the LT waveforms shown in the document you refer to, not surprisingly, look very similar to those in the article I referred in my earlier post; the only real difference being the voltages at various parts of the cycle which is to be expected for different system component values etc.

Andrew does your simulation software have anything like a neon tube/lamp as one of the elements. If so it may be possible to use this, especially if you can control the striking voltage, to roughly simulate the spark gap as this also exhibits the negative resistance characteristic when the gas ionises.

Cheers

Martin

Edited By Martin W on 03/08/2012 11:07:46

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