power for igniters

[SPONGE]

How much power is required to consistantly light Estes igniters? 6v? 12v? I need to make sure I have enough juice to light a cluster of 3 D12s. Thanks.

 

[Brian Barney]

6v is enough for a single one, but I would go with about 12v for a cluster. Be sure to wire the ignitors in SERIES because the voltage will decrease but the amps will stay the same, and amps is what is needed for ignitors. Use a high output 12v battery, like a motorcycle lead acid battery. Also, have fun with it, cluster rockets are really fun, and are more challenging to build and fly right

-Brian Barney

 

[James D]

Hey SPONGE, Sorry I cant off any advice, but I have a Q on Batterys for launch too( it is relevent!). Im thinking of getting a 12V Scooter battery - but how many amps are required? Shoud I just go and buy the One with the biggest current, which will garentee that it ignite the igniters? Or Do I try and work out the power drain on the battery?

Ps. SPONGE i would get a big Lead - Acid battery for cluster launch.

 

[MarkABrown]

Originally posted by Brian Barney
Be sure to wire the ignitors in SERIES because the voltage will decrease but the amps will stay the same, and amps is what is needed for ignitors.
-Brian Barney

I think you meant to say wire them in parallel. If you wire them in series, when the first igniter lights, the circuit is broken to the igniter on the far side of the loop therefore, it may never light. Both leads of each igniter should be directly connected to the clips of the power source.

 

[Lee Reep]

Actually, series or parallel works, but it is influenced by type of igniter. Most folks prefer parallel since with series, it seems like one could light, open the circuit, and not allow the others to light. Current is going thru all igniters in series arrangement, so if they are good (and similar) igniters, they are all going to light. (ie. if current will light one of them, it has flowed thru all and all will go.) Parallel, though, will give you the highest current per igniter.

A buddy of mine is in the fireworks business (more of a hobby for him), and they wire everything in series. Why? Only way to get continuity check. With parallel, it only takes one igniter hooked up properly to get continuity. With series, all must be connected properly to get continuity. Also, electric matches need only small current, so a smaller total current is fine, hence series is fine.

Look at the case of a 12v battery and a 1 ohm igniter. This combination gives you 12 amps current (current equals voltage divided by resistance). Put three igniters in series, and you get 4 amps current. In parallel, each igniter is exposed to the full 12v, so each gets 12amps. Obviously, as the cluster size increases, current is going to be a problem for series, but not for parallel. For electric matches, which require less current, series may be preferred, since you can easily determine continuity. For Estes igniters, that are higher in resistance, parallel is best.

 

[Brian Barney]

Originally posted by MarkABrown
I think you meant to say wire them in parallel. If you wire them in series, when the first igniter lights, the circuit is broken to the igniter on the far side of the loop therefore, it may never light. Both leads of each igniter should be directly connected to the clips of the power source.

Actually, the cool thing is that it doesn't instantly kill the circut when one burns before the others..... the small ball of ionized gas made from the hot pyrogen burning actually nearly shorts out the leads, making more current go to the remaining ignitors! I recently heard about this, and I think its really nice. The short circut only lasts for a split second, but that short is usually enough of a boost in current to light the other ignitors quickly. I read about this relating to daveyfire electric matches, estes ignitors dont have quite as much pyrogen on them, but it would probably still work, just for a shorter period.

Pretty cool eh?

-Brian Barney

 

[SPONGE]

I will be wiring my cluster in parallel. I have already built my clip whip. Can I get enough juice from two 6v alkaline lantern batteries wired together? Or do I really need to go get a lead acid for strong ignition?

 

[kgholloway]

The alkaline lantern batteries should be big enough to be AOK. The primary reason for using lead acid batteries is that they can be recharged reducing the overall cost. As for sizing the batteries any decent lead acid battery rated for motor starting should be able to supply more than enough amps for your needs. The small "lawn mower" or "motorcycle" batteries sold by Sears, Walmart, etc. are excellant.

Ken Holloway, NAR #78336, L-1