Building Launch Controllers

[lcorinth]

My personal launch controllers are built with Radio Shack parts and key switches obtained through American Science & Surplus. Picked up a spool of white lamp cord way back when the local Builder's Square closed. I use the 12v 7.5 Amp Hr sealed gel batteries--available through farm supply and outdoorsman stores (also Tower Hobby) as a power supply. One controller features an LED with dropping resistor so I must be mindful of polarity. One must view the LED directly to determine continuity. Your results may vary.

I'm planning yet another controller using a lighted covered toggle switch and a large heavy-duty push-button switch obtained at Harbor Freight Tools to be mounted in an aluminum project box.

I was looking at some of that stuff at Radio Shack yesterday. Even if I don't get around to building my own, I loved looking at all the cool switches.

 

[ttbit]

Each LED is going to be a different voltage these days, so you have to match the resistor to do the proper voltage drop for your LED. Better to have too high of a value than too low. I built one with RS parts as well. I use an ultrabright big LED. Takes almost no voltage to see that thing in the sun. First powered it with 4 AA cells. Too slow and weak. I then threw in an extra LiPo of 7.4v I had around. No more 3-2-1 - - - - - - -! . Now it is 3-2-1!!! Not sure what I am going to do when I need 12v. Maybe a LiPo 14.4. You just don't want that sucker to dead short too long as some of them will supply 30A. I guess this should be left for the crazy people like me. Anyway, something to be said about making everything yourself. I just built a pad also. Have not used it yet. I think it was overkill, but... I could swear my Big Daddy was too heavy for my 70's Estes pad...

I remember the days of igniters burning in two from leaving the key in too long with the old "lamp" in the 70's. I wasn't about to live that again.