Will a 9V Battery work for Ignition

[Hydra]

YAY ANOTHER NOOB QUESTION

Title says it all. I know i could use a BBQ Lighter but I have heaps of 9V batteries and only like 1 BBQ Lighter.
By the way, i did search and i went through the first few pages which would be the most relevant. After about 10 pages the results were coming up with Pneumatic Cannons and something about a silencer.

[MrCrowley]

Can you make a spark with just a 9v battery?

Not that I know of. Air resistance is like 10000v a centimeter, so if you had a 20000v volt ignition, it could jump 1cm. IIRC.

And this is only 9v, so I'm pretty certain you can't.


Just get a stun gun circuit from BCARMS.

[daxspudder]

its actually really easy, but a little dangerous. simply have both leads coming from two points 60 degrees apart, like 5 and 7 on a clock, at 12 have a tight fitting (tip removed, possibly padded) nail with the head inward, on the head attach a small ball of steel wool and viola, a ton of sparks. but once it goes off its probably gonna try to "remove the nail" so like a said a little dangerous, but it will work... just buy another grill igniter, your finger tips will love you for it.

[TurboSuper]

Well apart from shorting the battery, you technically can. After all, a stungun runs off a 9V battery.

Of course, the step-up circuit needed isn't something you can just throw together with band-aids and paperclips.

[psycix]

Or if youve got HEAPS of 9volt batteries, connect a several thousand of em together for a continuous spark

[daxspudder]

well there is another way, the way a stun gun works. first you have to use a series of zener diodes and capacitors, and a transistor to create a dc/ac converter. then your can simply make several (or one ridiculous) transformer, with ac power you can easily turn 9v(ac) into 1000000v if you wanted, but the current stays the same, which is why stun guns dont kill people, because voltage doesnt kill people, current (amperes) kills people, and a 9v lacks that, but now that im off topic, that is how you do it.

[Gippeto]

@ daxspudder

Are you implying that you can get more out than you put in?

Watts in = watts out (minus efficiency losses)

You don't by chance have a combustion AT-4 in the closet do you?

[Carlman]

You don't by chance have a combustion AT-4 in the closet do you?

lol Gip's got more brains than him

EDIT: reread

[daxspudder]

no, your right, i didnt read before i posted it, voltage change is inversely proportional to current change, but all the same the voltage is all that is need ed to jump the 12000v air resistance(per cm) current isnt as much a factor, as long as you use copper, and not a more resistive material, the current will not be a factor. and carlman i didnt see you give any answers for how to do it. so for a million volts from a 9v current will change from .0001A to 9.000009E-10 A, so for all intended purposes of his use, amperage doesnt change.

[jimmy101]

no, your right, i didnt read before i posted it, voltage change is inversely proportional to current change,

Ignoring losses, the voltage ratio (not voltage change) is inversely proportional to the current ratio.
V₁/V₂ = I₂/I₁

but all the same the voltage is all that is need ed to jump the 12000v air resistance(per cm) current isnt as much a factor, as long as you use copper, and not a more resistive material, the current will not be a factor.

The resistance of the wire has little to do with the behavior of a spark gap. The critical circuit resistance is the air before it breaks down. That resistance is in the mega to gigaohm range. So, it doesn't matter is your wire is 0.001 ohms/foot or 1,000 ohms/foot, compared to the resistance of the spark gap that is insignificant. Indeed, stock automotive ignition wire runs hundreds of ohms per foot.

so for a million volts from a 9v current will change from .0001A to 9.000009E-10 A, so for all intended purposes of his use, amperage doesnt change.

Hmmm, last time I looked a factor of 10E10 qualifies as a "change".

Again, ignoring losses, the total power is the same but the voltage and current change significantly, and in opposite directions. Of course, this assumes you aren't using any type of a storage device, like a capacitor.

With a cap, you can boost voltage, current and power, but the total energy is less than or equal to the input energy.

The 1.5V AA battery in a disposable camera flash unit will provide a 5~10KV spark at low current. In addition, even though the battery will only source a couple amps, the photocap can put out hundreds of amps at 300V for a milliseond or so.

[DYI]

Also, I think dax is underestimating the current potential of a 9V battery - at 9V, it can deliver more than enough current to kill by stopping the heart, the only reason that they aren't too dangerous for most people to handle is that the 9 volts isn't sufficient to penetrate human skin (in most cases). In the only incidence I can think of of anyone being killed by electrocution from a 9V battery is one in which the idiot attached spiked leads and jabbed one into each hand, providing a direct path across his heart.

So there is more than enough energy in a 9V battery to ignite an air/propane mix. The commonly quoted figure is 5mJ of energy required for ignition. The battery can supply far more than that.

Also, I REALLY want to see someone hook up 20,000 9V batteries in series and create a continuous DC arc 6" long for a few seconds until all the batteries overheat and explode.

[mark.f]

*Rummages* I'll donate three! I actually don't think the batteries will heat or explode, because they're still only putting out one cell's max. amperage.

I think you're best bet is to just use the BBQ igniter. You can get a 9$ piezoelectronic one or a 16$ electronic one from Wal-Mart.

[Eddbot]

i recently discovered that stick lighters are a cheaper source of peizos than paying 12 bucks for a grill starter, just my 2 cents...

[Hydra]

Argh my brain...Yeah im not good which electronics. Thanks for the info anyway.
I guess ill get a Peizo. O ya and Im and Aussie, no Wal Mart here.

[Carlman]

O ya and Im and Aussie, no Wal Mart here.

woot woot go aussie!

another one to the ranks.

urry up and get a sig so u can have an aussie flag up