Re: Help with 12 volt rocket igniter

On Mar 2, 10:39 pm, ULB <ultralightbackpac...@xxxxxxxxx> wrote:
Hi all,

I was looking into building a simple (but hopefully cool) model rocket
igniter. Yeah I'm bored, but stupid as a brick. About the only thing
I know about electricity is 110 volt hurts when you touch it. :)
Luckily this is only 12 volts. ;)

You can view the plans here: http://home.earthlink.net/~rbogerjr/index.html

If you scroll down and hit "contents directory" it will show you the
"how it works".

How does the lightbulb limit the current that is going through the
circuit without igniting the engine igniter? I am assuming from what
I have read is anything above 6 volts, ignites it like a fuse blowing.

I would love to build this unit, only I would like to change the
incandescent bulb to an LED in addition, add a piezo for an audible
sound as well. Where should the piezo be added in the diagram?

Can anyone shed some light for me on this? Thank you for any replies
and have a great night.

Tim and ehsjr,

Thank you for responding. I really am having a hard time grasping the
resistor. I understand it reduces voltage etc, but I do not
understand if it is like a hose, whereas the ouput is less, and
anything prior to that resistor is the original voltage.

I just drew up a plan based on the above rocket launcher. I was at
work today and read the internet instead of working. Don't tell my
boss. :) You can tell I didn't comprehend much.

In any case, I have changed the design slightly, well probably alot.
The launcher is now to be keyed, when turned in the 'on' position, it
shows the voltage in the battery(s), lights an LED and buzzes a
piezo. There is no longer a connectivity test to the igntiter
(probably safer I would hazard a guess). The launch button lights an
LED and then shorts the igniter and hopefully the rocket launches.
How do I keep the "launch" button LED Lit even if it doesn't fire? I
think I am missing a wire.

Thanks for the patience. Here is the link to my umm err drawing.

http://img247.imageshack.us/img247/7237/hpim0846cw4.jpg

.

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