Fly-swatter Ignition

[CpTn_lAw]

Hey there,
Been doing some spudgunning these days. So I took the old combustion out, and saw it needed another ignition since the previous one was missing.
This topic is about what I did to build this new ignition system.

The very simple idea behind this is "2kV from two 10nF capacitors in parallel, dumped into a LED".

I don't have pictures yet but here are some very simple steps to make it:

1) Grab an electric flyswatter. (they sell for a couple of bucks)
2) Grab multiple normal sized LEDs in case you break a few in the process (neither the flat ones, nor the very thin ones)
3) Open the electric flyswatter and solder a second capacitor of the same rating as the already existing one (A big flat cap, next to the wires that go to the electrified grid)
4) Remove the grid from the flyswatter and solder one wire from the circuit board (the ones closest to the capacitor) to one pin of the LED, keep the other wire as is.
5) Activate the flyswatter and let a second pass, then discharge the capacitors through the LED by touching the left alone wire with the second pin of the LED.
6) with cutting plier, gently cut the LED to where the little reflector ends (cut through the plastic)
7) Solder the second wire to the second pin of the LED

You're done.


It works like this:
The first discharge vapourises the thin wire inside the LED aswell as the little crystal causing it to leave a very thin gap between the electrodes, and building a small over pressure inside, cracking the plastic.
Everytime you press the button of the flyswatter now (while it being soldered to the LED) the voltage across the electrodes builds up, and when it reaches a high enough value, current is allowed to pass through the little bright arc that is generated.
I tried it in my 6L combustion chamber. The current going through the arc is high enough that a tiny plasma volume is created, generating a shock and igniting the flammable gas mixture.
Further testing needed to prove durability of the system, but I can certify that for now it has already been working all afternoon.
Depending on the spacing of the electrodes in the LED, the sparking frequency varies.


You're very welcome.

[jackssmirkingrevenge]

Look who's still burning gas

Great tutorial, looking forward to pics and videos!

[Labtecpower]

I once tried this with wood screws as the spark gap, didn't work for me..

I'm gonna try this one out, sounds like a good idea for a convenient ignition system

[mark.f]

With the LED, you're basically using the gap between the two anvil posts as a very small spark gap... so I guess my question here is why not fashion a small spark gap that's adjustable and with replaceable parts? Not trying to be snide or anything, just curious.

Also, here's a simple modification you can do with your current rig that I think you will enjoy thoroughly.

[CpTn_lAw]

Mark that's exactly how it works.

However, i don't have an ignition coil in hand right now, I only have two flyback transformer i used to build a plasma speaker.
I tried to hook them up to the flyswatter and well, it works, but i get a 4 inch spark and i get a little shock every time. The electric field is so intense that everything ferrous around aligns itself on the field lines. (some left over iron dust was on the ground of my room and jumped as i activated the circuit.)

I think what you're suggesting is to transform this basic setup into a sparkgap switch to trigger a much bigger spark between interchangeable electrodes. (A stungun per say)

This might very well work but as I said, I don't have a step-up transformer suitable for this design.
I might add that current might flow back in the flyswatter circuit, unless I use a Fast diode rated at the required voltage.

Great advice though, thanks a lot. I'll make a video today if I get the time.

[mark.f]

However, i don't have an ignition coil in hand right now, I only have two flyback transformer i used to build a plasma speaker.
I tried to hook them up to the flyswatter and well, it works, but i get a 4 inch spark and i get a little shock every time. The electric field is so intense that everything ferrous around aligns itself on the field lines. (some left over iron dust was on the ground of my room and jumped as i activated the circuit.)

I think I just got a semi.

EDIT:

This might very well work but as I said, I don't have a step-up transformer suitable for this design.
I might add that current might flow back in the flyswatter circuit, unless I use a Fast diode rated at the required voltage.

You could try wiring a simple 1n4001-7 diode in parallel with the load (coil) with the cathode positive as a flyback diode and seeing what happens. You can find rectifier diodes like that in pretty much any power circuit (CFL bulbs have them in the base).

[CpTn_lAw]

You got a semi? Didn't get that one.

I have a few 4007 diodes from the plasma speaker circuit.
I could have just built a simple 2n3055 + flyback igniter... but I already knew it worked so I wanted to try something else.

I just did a blank fire with a simple alimentary film burst disc. I forgot how loud this thing is... A 6L combustion with 2" barrel.

It ignites on the first try. I use syringe metering from a butane/propane bottle.

[jackssmirkingrevenge]

You got a semi? Didn't get that one.

I think he means that what you said provoked a state of semi-arousal in his genital area.

You know, when it's not quite turgid enough but you poke it in anyway, hoping it will get better as you go along

Of course I assume he was speaking figuratively

It ignites on the first try. I use syringe metering from a butane/propane bottle.

Amen brother!

[CpTn_lAw]

Oh yeah... that happens to me all the time...

You should have seen the face on my intership superiors when I played Muse in a Xenon UV arc lamp
That was like a very bright blue-ish white arc in a sealed glass bulb, and electric guitar screaming its way out
(I must say i was getting close to 120kV out of the flyback, with 15V / 5A input.)
The highest I was able to push in was 12 Amps @ 17V , but at the time, the anode was still stainless steel and got white hot, then formed a nice molten steel drop after a few seconds.
I used two electrodes from a Xenon arc lamp afterwards.

They were like:
-" trickery!!! "


More on the subject at hand, The current in those flyswatters is a little high, some wear is to be expected after a few hundred/ thousand arcs in the LED. Just twitch the leads a little and you're good.
I found some old transformers with bad ratios, so I wound out some wire to boost the step-up ratio. Good thing is, now I can get a 6mm gap easily, but after a few arcs (make it 50) the enamel insulation broke off and now it arcs to where it wants in the secondary windings.

[POLAND_SPUD]

I think he means that what you said provoked a state of semi-arousal in his genital area.

You know, when it's not quite turgid enough but you poke it in anyway, hoping it will get better as you go along

Looked at his avatar it says 'pics or it didn't happen'... thx JSR you just ruined my childhood

[mark.f]

JSR is correct.

See here.

[CpTn_lAw]

I have been testing and taking pictures from the ignition system.
I have replaced my casio EX-F1 with a Canon EOS 6D. Unfortunately, one of my lenses (a very old 28-70 mm) has broken a few weeks ago, beyond repair. So, there won't be any good quality videos until I buy a new wider angle lens. I'm stuck with a 100mm macro for now.
The picture here is a 3.2" second exposure @ f/8 and ISO 800. It has been cropped aswell, and a little post prod in lightroom gave it the nice life-like colour.
It shows nice detail and we can even distinguish the various plasma energy levels.

For those still unsure about wether or not a spark at the chamber wall will do the trick, search no more: yes it does. Ignition everytime at first spark.


Enjoy.

[jackssmirkingrevenge]

The picture here is a 3.2" second exposure @ f/8 and ISO 800. It has been cropped aswell, and a little post prod in lightroom gave it the nice life-like colour.

Fantastic!

For those still unsure about wether or not a spark at the chamber wall will do the trick, search no more: yes it does. Ignition everytime at first spark.

Lots of my hybrids use the same and it works great