Fireworks

[DSGarcia]

Use a cell phone to trigger ignition by completely shorting the battery. It will heat up in no time igniting the gasoline soaked newspapers.

Don't overcomplicate the circuit to react to a certain code. Just ignite on call.

(Derived from uncle Osama's hobby shop)

Some cell phones start fires without even trying: cell phone fire - Google Images

 

[MrDEB]

steel wool + 9v battery

in boy scouts they do it all the time.
for the pioneering merit badge they demonstrate starting a campfire using a 9 v battery and steel wool.
works very fast.

 

[smanches]

Who's talking about launches. I was talking about the real things - bombs.

When I was 14 I built the strongest bombs of all my friends. We used an abandoned military training area to add a few craters. My biggest one was 15m diameter and 3m deep.

Yes, who said anything about launches?

 

[BrownOut]

Much experience here.

Use model rocket motor igniters with a match or two taped to them. They work off 9v, at least for a few launches.

Are you saying my elegant thermal analysis was totally wrong?!?!?

 

[smanches]

Most of the igniter controllers I used as a kid were only a single 9V. They didn't last long, but you could get a dozen or more launches off one.

 

[BrownOut]

Did they use a hot wire? Either my analysis was wrong, or the simple 9V pile is more formidable than I thought.

 

[BrownOut]

...or, I overestimated the requried temperature. It' very possible that matches don't need 400 degrees to light.

 

[giftiger_wunsch]

...or, I overestimated the requried temperature. It' very possible that matches don't need 400 degrees to light.

I don't know if you're talking about fahrenheit or celsius... if it's fahrenheit, I have no idea how hot that is but according to a page I just found on google, match heads ignite at approximately 80 degrees celsius; I don't know about the reliability of that source, but it sounds feasible. Don't forget that match heads are explosive and have low activation energy, hence why you ignite them simply by the force of friction.

 

[smanches]

Found this, haven't read it all yet.

https://www.electro-tech-online.com/custompdfs/2009/10/igniters.pdf

The igniters themselves have a thick coating of a match like substance. There is a very fine wire between the two leads with the coating covering all of it. The wire gets hot enough to ignite the coating, which will then ignite the matches.

 

[BrownOut]

That's very interesting!

 

[Boncuk]

Don't forget that match heads are explosive and have low activation energy, hence why you ignite them simply by the force of friction.

That was proved in the USA back a decade or two. Boys made a multi-stage rocket using milk cans filled with 5,000 match heads. When they touched the rocket off one of them lost his life.

 

[BrownOut]

Thats why you need remote igniters.

 

[giftiger_wunsch]

I've heard of pipe-bombs made from match heads (eep) but rockets? Did it actually work as a rocket, or just explode and kill the unwary creator?

 

[smanches]

EDIT: Too early before coffee. Not sure what I was thinking...