RC Car Detonater

Hey guys I am fairly new to electronics and pyrotechnics. I have made black powder and can light it fine (Not compacted, trying to make a black powder rocket) with a 12 volt battery recharger that is used to recharge car batteries. But the thing i cant figure out is why a 9Volt battery wont light the powder when i got 2 peices of wire connecting off of it with a copper wire inbetween like the 12 volt does. I even put 3 9 volts in sync to make 27 volts and i tested it with one of those electrical testers that spits out how man volts or amps you have. But still no light. The reason i am trying to do this is because. I am trying to turn a wirless door bell or a alarm clock or a rc car to light this (most cheap rc cars will just with that much power) because i hate lighting fuses. I was thinking wireless so i can stand back a saft distance to light the powder and then when that works i build the rocket. I dont wanna just use the 12v and loads of wire because i hate carrying out 30 feet of wire or so. ANY suggestions on how i can use 9v or anything to make a small "detonater" to light this thing.

Thanks
John

Sorry, my sphincter is still sore after my last encounter with the "Patriot Act".

You can use a lower voltage but you need big amps to light your firework. If you think a PP3 will light your firework then study electrics a bit more. Get a lead acid battery and you will have no problem lighting your fuses.

Mike.

Exactly, it doesn't matter how many 9V batteries you connect in series, the short circuit current will be exactly the same.

Nicad AA batteries can kick out a fair amount of current and NiMH isn't far behind, connect 10 in series and you'll probably have more than enough current to ignite it.

So how do I know how many Amps are going through the battery? and would connecting a wire to the positive and negative terminals of the batterys couse it to heat and light?

Use a Relay. Simply connect the coil to the RC Car (in place of the motor) and wire the COM and Normaly Open leads in series with the 12V battery and the bom... ehem... black powder rocket.

I suggest you to install a switch between the relay and the rocket motor, and only turn it on when you are ready to launch. That's to prevent burning your face or hands with the exaust if the RC transmitter triggers accidentally (due an interference, a cat, somebody stomped on the button, or anything else) while you are setting the angle and azimuth of your little MLRS!

ematrix said:

So how do I know how many Amps are going through the battery? and would connecting a wire to the positive and negative terminals of the batterys couse it to heat and light?

Click to expand...

The usual way is to connect a large load to the battery, measure the voltage drop and use Thevenin's theorem to work out the internal resistance which will tell you the short circuit current and the voltage drop at different loads.

Thevenin's Theorem

An easier way is to read the datasheet for the battery.

Ok, answering your private message I made a pictoric image of what you have to do. I'm not saying you are a "Detonators For Dummies" user, I just made my best effort.

I think this circuit will work for your new application, but I don't know about fuses and the things you asked. Anyway,you have 12 volt 7,2 amp to play around.

originaly, I have made this system to turn ON/OFF remotely a high voltage experiment. Offcourse, following the "Menticol" tradition of failed electronics, a huge spark jumped and burnt the RC car.

If you want to use other parts, or for another non civilian purpose, is up to you!

PD: I love the AMRAAM!

Another solution is to connect a large capacitor in parallel with the 9V battery which will boost the peak current available.