Potato cannon spark

[da007man]

Hi, I'd like to make a spud gun, and to ignite the fuel, I was planning on scewing two bolts next to each other, in order for the spark to 'jump'. I would then like to connect the bolts to wires so that I can shoot the cannon from a distance. However, I do not know what kind of components to use. I would like to connect the wires to a project box, in which i will put a switch for "security" and a button for "fire". I would like to use a 9 v alcaline battery (the rectangular ones with bothes positive and negative ends on the same side). If a schematic is possible, i would be very grateful.
Thank you

 

[Hero999]

Try a piezo igniter which has the advantage of not requiring any batteries.

 

[coopersloan]

You can use a replacement push igniter for a barbeque. Cheap + easy.

 

[da007man]

I already thought of those possibilities, but as i said, i would like to connect wires to the bolts so that i can shoot from a distance, i am going to use hair spray as a combustible, should i use a capacitor to discharge a spark? i am not looking for a quick find in your house spark generator, but somthing that i can make myself, with a battery, a switch and a button to release the charge

 

[imix500]

When I had my tater cannon ~15 years ago, I used a ignition coil from an old Ford truck with a spark plug in the chamber. I mounted a large 60A 12V contactor wired to "chatter" and rapidly fire the coil. Remote control of that sort of setup would be easy. If I did it again, I would make the firing circuit solid state.

 

[Hero999]

You can use a disposable camera flash charger and a 12V to 240V mains transformer

Remove the large capacitor and replace it with a smaller one, 100nF or so, charge the capacitor (this should happen very quickly) when you're ready to fire, discharge it in to the 12V side of the mains transformer

 

[Mikebits]

Why would you want a remote fire of a potato gun?

 

[Sceadwian]

Hero's original solution of a piezoelectric ignitor is still the best idea... You won't find a simple home made solution for a high voltage arc using a battery and a few simple components, they simply do not and can not exist.
coopsers post is an echo of Heros.
Even if you want remote it'll still work over a length of wire.

 

[RCinFLA]

When I was young we used to strip a single copper strand from lamp cord. Wrap a couple of space wound turns on the fuse cord of an M-80 fire cracker to set it off via a 12v battery.

 

[keny]

Why would you want a remote fire of a potato gun?

Maybe you want to mash yourself with potatoes....

 

[Hero999]

Unfortunately piezoelectric lighters tend to be ineffective at long distances because the high impedance output is poorly matched to the low impedance cable so lots of the pulse is lost in the cable capacitance. Minimizing the capacitance seems to be the key, using two HT leads ran with a large distance between them should help.

An efuse sounds like a good idea, fine copper wire should be enough to ignite the flammable gas, the disadvantage is, it's single use only.

An ignition coil will certainly work but you need a 12V battery, a 9v will probably have too higher impedance and the voltage might be too low, you could try charging a large capacitor and possibly using a voltage doubler.

 

[MrDEB]

If the piezo idea is out the window then use an ignition coil and battery with a relay that acts as a set of points. Control the relay from a distance.
very basic and cheap. not as cheap as the piezo BBQ igniter.

 

[Hero999]

Here's another camera flash related idea.

This one will fire automatically and will repeat if the capacitor charger is the sort which caries on charging, after the flash has been triggered.

Increase C1 for a more powerful spark. Don't go too high otherwise it will ruin the transformer.

R1, R2 and D1 control the voltage at which it fires, in crease the voltage for a longer and more powerful spark. The maximum voltage will depend on the capacitor charger.

 

[da007man]

Why would you want a remote fire of a potato gun?

because i bought a miniature of an old cannon, and i want to replace the fake barrel with my potato cannon, and then with the remote, shoot it without having to go on my knees and press a button...

 

[da007man]

thank you very much, but when you mean automatic, like it's continuous and never stops, or just fires once it's charged? sadly that is not what I want (sorry if i'm a bit picky, but have to stick to the project subject). You're other disposable flsh camera idea seems good, however I do not quite understand, can you maybe draw a schematic for me?
Thank You

 

[da007man]

this was meant for HERO999

 

[da007man]

Here's another camera flash related idea.

This one will fire automatically and will repeat if the capacitor charger is the sort which caries on charging, after the flash has been triggered.

Increase C1 for a more powerful spark. Don't go too high otherwise it will ruin the transformer.

R1, R2 and D1 control the voltage at which it fires, in crease the voltage for a longer and more powerful spark. The maximum voltage will depend on the capacitor charger.

please read the next posts that i put, i forgot to click on reply with quote :/

 

[Hero999]

thank you very much, but when you mean automatic, like it's continuous and never stops, or just fires once it's charged? sadly that is not what I want (sorry if i'm a bit picky, but have to stick to the project subject). You're other disposable flsh camera idea seems good, however I do not quite understand, can you maybe draw a schematic for me?
Thank You

I'm not sure what you mean.

Whether the spark is repetitive or not depends on the disposable camera capacitor charger.

Did you notice the schematic attached to my previous post?

It shouldn't make any difference whether the spark is repetitive or continuous because you only need one spark to ignite the gas. Just put a switch in series with the battery powering the disposable camera capacitor charger.

 

[da007man]

I'm not sure what you mean.

Whether the spark is repetitive or not depends on the disposable camera capacitor charger.

Did you notice the schematic attached to my previous post?

It shouldn't make any difference whether the spark is repetitive or continuous because you only need one spark to ignite the gas. Just put a switch in series with the battery powering the disposable camera capacitor charger.

Ok now I understand. Sorry, I'm not very familiar with components. By disposable camera capacitor charger, you mean the camera is supposed to charge the capacitor? If that's so, am I supposed to press the 'capture' button to make a spark.
Once again sorry if my questions seem obsurd.
Thank you

 

[da007man]

Here's another camera flash related idea.

This one will fire automatically and will repeat if the capacitor charger is the sort which caries on charging, after the flash has been triggered.

Increase C1 for a more powerful spark. Don't go too high otherwise it will ruin the transformer.

R1, R2 and D1 control the voltage at which it fires, in crease the voltage for a longer and more powerful spark. The maximum voltage will depend on the capacitor charger.

What is the D1 sign?