[TriEmbed] Rocket derby help

[John Vaughters]

Craig,
I do not know what it takes to light the fuse, but right off the bat, your currents seem tiny. Are you sure you got the scale right? Also, cat 5 cable does not transmit alot of current, but it may be enough. I just do not know how much current you need. I also do not have the specs on the igniter and what voltage/current is proper. I think you need to start with the specs for the igniter, look that up first. Then consider upping the voltage at the button box to get the proper voltage at the igniter. If it worked before then it may be as simple as verifying the specs of the igniter and the provided voltage, but be careful if it is truly only cat 5 cable. It is very low current cable.
Did I miss the email about the car race results and solution? If not, please let us know how it went.
Thanks,
John Vaughters 

    On Monday, January 30, 2017 9:43 PM, Craig Cook via TriEmbed <triembed at triembed.org> wrote:
 

 Now that Pinewood derby is over, onto my next challenge.

Last year I was launch master for our Cub Pack.  We have been having problems with our rocket launch system.  6V large square battery powers the system.  There is a rotary switch where you can select from position 1,2,3 or 4.  This box is connected via 45 feet of cat 5e wire to junction box (DB9 serial connectors attach from the launch box to cable, and another one to the junction box).  The junction box is split out to 4 sets of wire with alligator clips.  These clips attach to the rocket fuse (1,2,3 or 4).  The Cub presses a button on the launch box, energy is dumped into the fuse and the rocket should take off.

The last few years we have had problems with the fuse not getting enough energy to burn fast enough and launch the rocket, result is an unhappy Cub.

I cut off and re-soldered the alligator clips thinking that would solve the problem.  It didn't.  I checked and I have 0 resistance from the junction box to alligator clips, so I think my soldering was ok.

I measure 1.2 ohms of resistance from the launch box to the junction box going over the 45 feet of wire.

Battery has 6.5 Volts, at the junction box I measure 4.19 Volts.

Battery has 0.005 Amps, at the junction box I have 0.003 Amps.

Is there a way to store energy at the junction box, then have it released when a switch is pushed?  I think that is what a capacitor is for, but not sure.


I was considering replacing the cat 5e wire and DB9 connectors with RJ45 ones.  Would that help?

No idea how old the batteries are, are the Amps too low?

Whoever made this setup knew what they were doing.  It has been well put together.


Thanks

Craig

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