burning a resister

[nic8082242]

in this video http://www.youtube.com/watch?v=-770uMBQ ... re=related" onclick="window.open(this.href);return false; it states that 12V will burn through a 10 Ohm 1/4watt resister. I am just wondering where I could get a 12V battery to do so. If it matters on size I need it to fit in 5 1/2" x 2 1/2" x 1". Any help would be appreciated.

EDIT: Lets say a normal AA battery has 1.3V could I just run 8 AA batteries in a series to get 12 volts, (I know it 10.4 but switches I'm using can't exceed 12V, so if they actually are 1.5V 8of them would be 12V) would this still burn through the resister?

Got my resistors in today, yeah they definitely burn with 12V(hooked it up to my PS, now I just need a 9V to test that part out.

[nitro2k01]

Let's do the math. The 1/4 W mark means that you should exceed a quarter of a Watt, or your resistor may burn. Of course, since you want to burn your resistor, you should exceed it, and with some margin to ensure it starts burning properly.
You can get the effect applied to the resistor by the formula P = U*I or, by inserting Ohm's law, P = U^2 / R. For 12 V and 10 Ohms you get 12 V*12 V/10 Ohms = 14.4 W = well above the 1/4 W.
What about a 9 V battery? 9 V*9 V/10 Ohms = 8.1 W, still well above 1/4 W. However, 9 V batteries sometimes can't prouce currents as high 900 mA. Even so, that current is going to to through the battery for such a short time that I don't it will hurt battery. And I think the effect will be high enough to ignite the resistor, even if it takes a second longer.
Or, you can try connecting two 9 V batteries in series, so you get 18 V. 1.5 V * 9 = 13.5 V will work just fine with your switch, and I'm pretty sure even 18 V will. There's noting in your switch that will make it magically fail at 12 V. (I'm assuming we're talking about a physical push/rocker/whatever switch and not a solidstate switch) It's all about tolerance levels. When you go above 12 V you increase the risk that the switch will fail for one reason or the other. For example, if you use the 18 V connection using two 9 V batteries, the switch won't fail immediately, but its lifespan might be reduced from, say 5 years instead of 10. If you use it for 110 V however, it will likely fail faster and/or be a hazard to the user.

[nic8082242]

thanks I'm gonna order the rest of the stuff for my project either today or tomorrow, first using 9V, depending on how long it takes I may end up using 18V. thx for the info

[nic8082242]

Found the batteries I will be using (2 wired in a series).
http://www.batteryspace.com/index.asp?P ... rodID=1995
Think they'll work okay?

[vskid]

Why are you burning the resistor? If you're only doing it a few times, just get a few alkaline 9v batteries. Or get a suitable wall wart.

[nic8082242]

haha firework detonator

So far I've seen this
http://www.batteryspace.com/index.asp?P ... rodID=1995
http://www.batteryspace.com/index.asp?P ... rodID=1618

roughly the same price, which one should I get?

[vskid]

Oh, I guess I should have watched the video first.
Honestly, I'd just use alkalines. If you use NIMHs, you'll need to buy a charger, too, you could buy many alkalines for the same price. You could also use 9.6v battery packs from RC cars, shouldn't be hard to find them and charger(s) for cheap if you have a decent thrift store/online classifieds.

[nic8082242]

Think I'm just gonna go wit this one
http://www.batteryspace.com/index.asp?P ... rodID=1618

[vskid]

Think I'm just gonna go wit this one
http://www.batteryspace.com/index.asp?P ... rodID=1618

May I ask why? It isn't even rechargeable.

[nic8082242]

Oops I meant to post the other one
http://www.batteryspace.com/index.asp?P ... rodID=1995
Just gonna get 1 to start out with, see how it lights the resisters, how hard would it be to add in a charger sometime down the road?

[nic8082242]

here's my diagram, sorry for the crappiness just through it together in paint


weird slant in the top left is a speaker terminal, makeing for easier disconnection. Wont finish project for a couple more weeks, buying concert ticket this weekend, might be able to get the case, battery, and soldering iron by next weekend (July 25)

[nevermind1534]

Think three switches/buttons is enough?

[nic8082242]

Key switch is for safety, so no one (little brother/little kids/friends at parties don't set them off) toggle is to arm, and momentary switch is to ignite when I feel necessary

[timmeh87]

Question:

Why dont you get 1 ohm resistors?

Next question:

Why dont you use steel wool instead of resistors (1 bag of steel wool will last forever)

[Aguiluz]

How about Nichrome Wire with a 6V Lead Acid Battery?