grimlock3000
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All of the information in this thread came right from this forum, it was just spread out over a bunch of threads. I have gone through a couple previous failed efforts at building my own 12v launch controller. This thread is about what I ended up with. The controller that can handle clusters, is perfectly NAR compliant to the best of my knowledge, and easy to build with Radio Shack parts and really basic soldering skills. I am going to post everything up here and hopefully it will help someone else so they do not have to go through all the rewiring and frequent trips to Radio Shack like I did. This controller should cost about $25 but it can be cheaper if you already have some of the stuff. After buying the wrong parts and messing up a few things along with wasted gas, my total money spent is around $55
First up, the list of parts and prices...
*Project box* $3.69:
https://www.radioshack.com/product....1_002_012_000&product_id=270-1803&site=search
*Interlock key* I have the contacts soldered together inside the top to complete the circuit when the key is inserted $2.99:
https://www.radioshack.com/product....11_003_001_002&product_id=274-266&site=search
*Interlock holder* The online pic is wrong for this, the real thing has only two contacts for a mono plug. Make sure you wire the bottom plug to the firing switch when you use this $2.99:
https://www.radioshack.com/product....11_003_001_009&product_id=274-252&site=search
*Continuity check LED with built in resistor* $1.99:
https://www.radioshack.com/product....11_006_001_000&product_id=276-271&site=search
*Continuity check Piezo buzzer* $4.29:
https://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=273-060
*Momentary launch button* 12V DC @20A, or @40A if wired in parallel. You can also wire this to fire when pressed up, down, or either $4.49:
https://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=275-709
That comes out to $20.44 before tax. Since the continuity checks are redundant, you can choose to use the LED OR Piezo buzzer if you want so the price can be even lower. Not listed is the 16g speaker wire I used ($5), a few washers (25 cents each), the alligator clips ($2), and 12v plug ends ($2). You can use whatever fits you application for alligator clips and 12v ends, just make sure it can handle the current of launching a rocket. For wire, use 18g or thicker. I went with 16g to be on the safe side.
Here is the wiring diagram of the final design. Red is positive, black is negative, and green is conditional (not connected unless the key is inserted or switch if pushed):
The LED and Piezo combined only draw an average of 17mA which is OK for the continuity check. I tested the controller a bunch and did not find the Piezo very loud at all. It is very easy to put the buzzer on a switch if you want to be able to turn it off.
And finally, here are the pics of the real thing...
*Internal wiring* I used electrical solder for everything instead of push on connectors. I also used epoxy to secure some wiring and the buzzer so nothing shakes around inside the controller. I connected the leads of the momentary switch so it works if you push it up or down:
*Outside shot and interlock* I used large washers to keep everything secure on the lid of the project box. Using a mono plug for the interlock key works really well too, it is a very solid connection:
*12v power source* This is the starter box for my RC nitro truck. Inside the starter box is a 12v sealed lead acid battery. This could just as easily be a car battery if you wanted:
*Mess* You can see the controller panel from my first failed controller in this shot:
Thanks to everyone who helped me out with this, now I hope I can help out some other people
//Update//
*Clip whip* I put this together with two butt connectors, some heat shrink tubing, colored zip ties, and mini alligator clips:
First up, the list of parts and prices...
*Project box* $3.69:
https://www.radioshack.com/product....1_002_012_000&product_id=270-1803&site=search
*Interlock key* I have the contacts soldered together inside the top to complete the circuit when the key is inserted $2.99:
https://www.radioshack.com/product....11_003_001_002&product_id=274-266&site=search
*Interlock holder* The online pic is wrong for this, the real thing has only two contacts for a mono plug. Make sure you wire the bottom plug to the firing switch when you use this $2.99:
https://www.radioshack.com/product....11_003_001_009&product_id=274-252&site=search
*Continuity check LED with built in resistor* $1.99:
https://www.radioshack.com/product....11_006_001_000&product_id=276-271&site=search
*Continuity check Piezo buzzer* $4.29:
https://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=273-060
*Momentary launch button* 12V DC @20A, or @40A if wired in parallel. You can also wire this to fire when pressed up, down, or either $4.49:
https://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=275-709
That comes out to $20.44 before tax. Since the continuity checks are redundant, you can choose to use the LED OR Piezo buzzer if you want so the price can be even lower. Not listed is the 16g speaker wire I used ($5), a few washers (25 cents each), the alligator clips ($2), and 12v plug ends ($2). You can use whatever fits you application for alligator clips and 12v ends, just make sure it can handle the current of launching a rocket. For wire, use 18g or thicker. I went with 16g to be on the safe side.
Here is the wiring diagram of the final design. Red is positive, black is negative, and green is conditional (not connected unless the key is inserted or switch if pushed):
The LED and Piezo combined only draw an average of 17mA which is OK for the continuity check. I tested the controller a bunch and did not find the Piezo very loud at all. It is very easy to put the buzzer on a switch if you want to be able to turn it off.
And finally, here are the pics of the real thing...
*Internal wiring* I used electrical solder for everything instead of push on connectors. I also used epoxy to secure some wiring and the buzzer so nothing shakes around inside the controller. I connected the leads of the momentary switch so it works if you push it up or down:
*Outside shot and interlock* I used large washers to keep everything secure on the lid of the project box. Using a mono plug for the interlock key works really well too, it is a very solid connection:
*12v power source* This is the starter box for my RC nitro truck. Inside the starter box is a 12v sealed lead acid battery. This could just as easily be a car battery if you wanted:
*Mess* You can see the controller panel from my first failed controller in this shot:
Thanks to everyone who helped me out with this, now I hope I can help out some other people
//Update//
*Clip whip* I put this together with two butt connectors, some heat shrink tubing, colored zip ties, and mini alligator clips: