Compact Ignition System?

[Gaderelguitarist]

I've been wrestling with a cannon in progress for about a week now, simply trying to get the ignition set up to spark effectively.

Essentially the ignition is a piezo sparker from a long nose lighter. I have it set in a hole of a wooden grip I fabricated.
*The piezo from the lighter is either not strong enough to create an 1/8" spark, or it is shorting through several layers of heat shrink. I'm more inclined to think the later. Further testing is needed.*

My question is probably going to sound naive as I'm not so much versed in the world of electrical things:

What would be the most compact, battery powered ignition system?

Ideally I'd like to have a push button switch with a light enough pull to feel good under the finger, so the best solution would be a battery powered option.

I've taken apart a disposeable camera to utilize the flash circuit, but am still hesitant to go further.

Any thoughts?

*Edit

[jimmy101]

Best bet is probably a battery operated BBQ igniter. Check the local hardware store near the BBQ parts. Probably cost something like $20.

[Technician1002]

Even smaller is the battery ignition on some cigarette lighters. They are harder to find (not on the throw away lighters) and cost a pretty penny. You can tell these as these lighters use a battery, operate without the loud click and often look very pretty. They are often listed as having electronic ignition. Be aware many pizeo units are also listed as having "electronic ignition" Look for one that does not click and does use a battery.

[Gaderelguitarist]

@ jimmy101:
Is this what you were referring to?
http://www.homedepot.com/Outdoors-Grill ... ogId=10053
*Although the one at Lowes is $10 cheaper...*
This looks like a great option.

@Technician1002:
In my searches, I've found one link that is at all relevant to what you've suggested.
http://www.amazon.com/Flat-World-Batter ... B0032LUGFI
*Upon reading a description fo the operation of these, I find myself wondering whether it created a spark, or simnply heats up*
This also looks promising, however hard to find it will be.

Thanks for the responses.

*Editted for additional content*

[maxa1]

i was thinking that you could wire a momentary switch up to a 9 volt and then use a small peace of steel wool aroung the sparters in the chamber but i think that might not be worth the effort so i would go with a grill lighter p.s you can get them for free off of old grills on the side of the road thats what i do
good luck !

[Gaderelguitarist]

@maxa1:
Indefinitely I would like the system to use a momentary push button switch to fire the spark. However the system needs to be relatively maintenance free, i.e not having to replace fried steel wool. I like the idea though. Just not for this particular design.

What I may find myself doing is wiring an external ignition system with which a momentary button may be switched on. The pistol grip I am using is simply too small for a standard grill piezo. However, if I were to find something similar to UltimateSpudgun's prewired ignition circuit that I could mount on the side of the chamber and connect to the leads I have going into the chamber, while still wiring it to the momentary in the grip on the bottom side of the chamber, then I would be very happy indeed.

[Crna Legija]

how about the pezo and lighter in the chamber

[theBOOM]

@Technician1002:
In my searches, I've found one link that is at all relevant to what you've suggested.
http://www.amazon.com/Flat-World-Batter ... B0032LUGFI
*Upon reading a description fo the operation of these, I find myself wondering whether it created a spark, or simnply heats up*
This also looks promising, however hard to find it will be.

Thanks for the responses.

*Editted for additional content*

Bah I found a link to it : http://cgi.ebay.com/AAA-BATTERY-CIGARET ... 35a5c8f075
(SORRY, I still dont know how to make the link little)
Anyway on the description it reads that it actually heats up, it dosen't spark, though there might be a lighter that actually sparks and dosen't heat up like this one does. I'll have my eye out for something like this, as I too am building some rather small for the mini contest.

EDIT: found 2 lighters on ebay that actually ingnited using batteries but they are both frikin expensive (30 to 50 bucks)

EDIT 2: After looking for like an hour I finally decided to google it and I came up with one good result, it's an indian commerce site though
http://shopping.rediff.com/product/batt ... r/10413032

[Gaderelguitarist]

how about the pezo and lighter in the chamber

I would resort to this if it did not interfere with my design. The whole concept is to make a 1" bore combustion that is aesthetically pleasing. The design has a pistol grip, and a pistol grip the gun shall have.

@theBOOM:

I'm almost positive that there will not be a cigarette lighter that sparks. It's a sad world we live in.


I had a thought earlier that may or may not work. Does anyone remember those gag shocking pens? The circuitry would have to be compact, it runs on batteries, and I'm fairly certain it could handle a 1/8" spark gap.

[mark.f]

Those gag pens may not have enough voltage to jump a spark gap. They don't need to be too high in voltage for you to feel it.

However, the circuitry in one of those pens is very similar to an old style spark coil, if I remember right. I just don't think the ratio of the coil in them is good enough to jump any gaps.

If you go the electronic BBQ igniter route, I would look on eBay first, and find one that isn't completely potted in epoxy. This way, you could take off the battery holder and compact it as much as possible to fit where you need it.

Another point: for a few extra dollars, UltimateSpudgun has a similar product to an electronic BBQ igniter that will run off 9 volts.

Lastly, if you feel like running a camera flash circuit, you can simply solder off the old flimsy battery holder(s), trigger switch, and charging switch off the board, and replace them with what you'd like (momentary switch for the trigger switch, toggle or momentary for charging switch, run some leads off the board from where the LED goes to install it on a project box, etc.), and then wire a small ignition coil in series with the flash tube.

Lot of suggestions, but I'm working in the same area right now.

[Insomniac]

Those gag pens may not have enough voltage to jump a spark gap. They don't need to be too high in voltage for you to feel it.

However, the circuitry in one of those pens is very similar to an old style spark coil, if I remember right. I just don't think the ratio of the coil in them is good enough to jump any gaps.

The gag pens can jump a gap, but it is an incredibly small one. They tend to be lowerish voltage (probably 200 to 1000 volts as an estimate) One of the ones I semi-dismantled had a tiny internal spark gap (I believe some spudguns have the same... not the large internal gap to protect the circuit, but a tiny, tiny one that has somthing to do with the pulsing current needed for a transformer to work). It would possibly work to ignite a perfect mix but it probably isn't a very good solution.


Has anyone tried messing with the flash tube trigger coils you can buy? The tiny one on a disposable camera can produce a small, faint spark which jumps a few mm and I've seen much larger coils at electronics shops (even bought a couple to mess with but never wired them up properly... just shorted caps through them trying to get a bigger spark as they were cheap).

[Crna Legija]

you could use a pistol shaped lighter

[mark.f]

Has anyone tried messing with the flash tube trigger coils you can buy? The tiny one on a disposable camera can produce a small, faint spark which jumps a few mm and I've seen much larger coils at electronics shops (even bought a couple to mess with but never wired them up properly... just shorted caps through them trying to get a bigger spark as they were cheap).

The trigger coils can be used for their own, very small spark gap, or they can be used in a three-electrode spark gap. I've never used the first method, but the latter method I have... it's a pain.

[Insomniac]

Yeah I knew the 3 pin thing works but is tedious, and I believe they tend to wear as the big capacitor erodes the metal of the electrodes?

I'm just curious as to whether a larger trigger coil would have the uumph to work as an ignition source. I've experimented with the sparks from a small van de graaf generator and have been unable to get them to light anything (perhaps because the sharp spark gaps don't allow a strong enough charge to build before it jumps)

[Gaderelguitarist]

I think for simplicities sake, I'll just order the 30kv ignition circuit from UltimateSpudGun. I had mentioned it earlier in the thread as an option, and am finding myself more and more attracted to it.

All this talk of transformers and coils and capacitors is racking my brain. I'm going to go sit in the corner and cut wood.

Has anyone ordered from USG before? I'm trying to get an idea of shipping hassle and what-not.