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I need some help an an ignitor box (loook in details)?

me and my brother had built an ignition box (1st project) that can be used for rockets and fireworks we sucsessfully had gotten the box to launch. Then we had the idea to add 6 volt lights and an organized switch setup. But we came across the issue of the circut bypassing our negative lead for our 6 light by the positive lead from the 5 light going to switch 1 so therefore basicly switch 7 isnt needed exept to light-up light 6. So now we need help on how to prevent this issue from happening. please help and thanx- Jarred

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lemonie7 years ago
(Please note what frollard says about the lamps/lights)
I hacked your image, using 7 as the master-switch for the ignition circuit. Hope you can see how this is wired?

L
launchbox.bmp
bluejuice (author)  lemonie7 years ago
thats a good idea but alll i really want isto figure out how to stop the circut from bypassing
You circuit has problems (as it's pictured). I've rearranged it to a form I think will work, solving those problems. However:
The bit you circled should come out, switch 7 is no use.
Do that and ignitors aren't connected to both ends of the battery, switch 1 needs to connect to the same terminal as the (unnumbered) switch for the lights
Do that and switch 1 will trigger all the ignitors simultaneously.
In order to power lamp 5 you have to switch lamps 2-4 on, and I doubt it would work even then. You have similar problems with lamps 2-4.

L
Exactly...I never described what was wrong with the original - this is it. The switches are in series... This just means you could fire #1, but the light would only light as you turn switch 1 on. THEN, with switch one closed, you could fire number 2...and so on. No good. :(
The circuit was plain wrong. Having the lamps Leds or what in series means that subsequent hotwires (ignitors) will operate at increasingly reduced wattage, even if it was his intention to fire all enabled rockets or explosives simultaneously. This is not good design.

Each output circuit should be in parallel with the source, EVEN IF the intention is to have the circuits set so that 2 will only enable if 1 is enabled and so forth... He has a cirucit (several acvtually, on one of the other parallel threads...

sincerly, Osoe confuste.
agreed 100% :D
frollard7 years ago
My understanding from igintion launch boxes - at least the diagram which is in my estes rocket launcher box... there are 2 parallel circuits - one that passes just a little power through the ignitor to light an led (through a resistor to keep the power down). This amount of power is not enough to even warm the ignitor, but you're sure its hooked up. There is a switch short circuiting the led and resistor. When you close the switch, the resistor is gone, and its a short circuit - drawing a few amps to ignite the firework.
ignitor.PNG
at 6 volts, the 470 ohm resistors will allow 12mA to flow lighting the leds, and again, keeping the ignitors FAR from igniting.
right. Hotwire ignitors using ~30ga nichrome or nichromel (sp) require an amp or so (actually,. my recollection from doing ignition of microgravity combustion experiments is something closer to 2or 2-1/2 amps) to glow red, although we never used dipped tips because of chemical contamination, so I'm not sure if it needs to go incandescent)
bluejuice (author)  frollard7 years ago
thats why we are using 6volt lights
Light bulbs work too...but see how this drawing is fundamentally different from yours? Each switch shorts out the light bulb, not connects it.
seandogue7 years ago
See my answer in your other post on this subject Bluejuice. I think it should resolve most of the problems, although I now see from the above posts that you'll need resisotrs in series with each of your LEDs to avoid popping them like firecrackers!