The difficulty in what you want to create is the variability of it. Sorry for the plagiarism of your circuit diagram, but I am a visual person and it helps me to put it all together in one diagram like this to make sure I have everything right. Please read previous comments before asking a question. With many cycles happening within a second you can blow several transistors quite easily. However it lacks the power and amperage that is forced through the arc in welding applications. The output current could be measured by placing an ammeter in series with the output, or by measuring the voltage drop across a small resistor and calculating it using ohms law. Hi, I am looking to build a very small circuit to allow aftermarket rev counters to read a 12V square wave — effectively a miniture replica of the driver and primary side of an ignition circuit.

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Once a charge is built up in a coil and the primary circuit is switched off, what happens to the charge in the secondary winding if there is no path for it to discharge to? This would be true if it were possible to instantly stop the curent flowing in the inductor, but because of several factors, this can not happen. If one look at the datasheet for the mosfets, they have a certain energy they can tolerate after the zener in them lets go.

I have some links saved somewhere form when I designed an air cored inductor for something else, for which I also bought an inductance meter. This a mostly in regards to the destroyed transistors and what ate them. With the engine running, I am getting a reading of A larger capacitor will allow more AC current to pass through it.


Yeah, my box is pretty large, but if one want it more compact just use one coil and the driver, about as large as only the ignition coil and the battery. I have built the second circuit on this page using your signal generator which works great.

If a DC output is ok, then you could use the ignition coil to drive a voltage multiplier for increased voltage. Please be aware that the output from this terminal is highly dangerous and quite deadly.

You mention a diagram by dr strom, what is the post number of this diagram? It would be really cool.

DIY Homemade Ignition Coil Driver – RMCybernetics

The transformer will prrobably survive this sort of ignitiob if it is just intermittent, but if switching transistor is used for controling power to the coil, it will overheat and blow in a relativley short time.

What changes would be required to this circuit if a hall effect sensor and a igbt was used in place of T1 and T2? When the two sides meet, a conductive channel of air will exist between the electrode allowing more current to flow.

In fact, the metal can is untouchable after a few seconds of arcing. Most older ign coils are around 1. If the outputs are connected together they will operate as a single ignition coil would but with the potential to deliver 2x the current.

The driver must be square wave to work properly. The current limiting effect of a capacitor can be calculated as follows. Igintion basic idea is that you place a MOV between any two points to limit the voltage that appears there.


DIY Ignition Coil Driver

I was able to create a tiny arc 3 mm by adjusting the frequency and duty cycle, and the diode D1 got quite hot. Thanks a lot for your help. Also, if this is correct, it seems that a perfect square wave would produce an infinite voltage across the inductor, but this is obviously not true.

So the coil driver wire seems to be fine. I chose the 2n because it can carry more current than the and it should take less of them to do a larger job. Ones ignituon higher voltage ratings will be less likely to be damaged by spikes. How long can this thing work Continuously?

Your supply is likely to get damaged unless you are able to suppress the voltage spikes msfet. This cap is a high frequency type very similar to the one used on the points in a conventional ignition.

How well it works will depend upon the transformer, but it will need to have a reasonably low input impeadance. The is fine.

A larger one might be better though. A flyback may be a little more stable than an ignition coil, but if there is no load on the output you will still get some spikes induced back into your low voltage circuit.