I built this recently, basing it off of other designs, and using car wiring methods as my system. this system uses one common wire. usually the positive wire as a common wire with all the switches and each wire being a negative current. to save space i chose to use 2 9 volt batteries instead of the rechargable large 12 volt. i also chose to not use LEDs for sake of saving space
Step 1: You Will Need:
all of this can be bought at radio shack for a total of around 30 dollars
mid sized hobby box
2 9v battery holders
2 9v batteries
4 button switches
1 regular switch
6 position wire terminal
1/4 inch diameter bolt and nuts
2 jumper plates for wire terminal
Step 2: Wireing
the wiring begins by first splicing the negative to the negative and the positive to the posotive on the battery holders. then add the normal switch to the positive line for use as the master switch, this will serve similarly to an on/off switch.
Then wire the terminal, with the plates screwed onto it, to the negative line. then wire a line to each of the 4 positions on the other side. each of these will need to be soldered to one of the leads of the corresponding button switch.
Next solder a wire to each of the button switches on the other lead.
Now the wiring is for the most part, done. all that needs to be done are addition of the leads for the detonation wires to clip to.
however before this can be done, holes for switches need to be drilled. i used a 1/2 inch bit for the buttons and a 1/4 inch but for the leads, and a 1/16 inch bit for the
wires to attach to the leads
to begin, measure a line running exactly down the middle of your box, then drill 4 1/2 inch holes equally spaced along this line. then make a 1/4 inch hole in the bottom right corner for the master switch. next drill 5 1/4inch holes, each for a line on the side of the box with a 1/16 inch hole above it for the wire. then thread the wire through the small hole and a bolt in the larger hole. then wrap the bare end of the wire around the bolt and tighten the nut on the bolt. do this for each wire
see photos below for wireing details
Step 3: Cramming All This in the Box
below is a diagram and a photo for how to fit this all in the box. I used gorrila glue to glue the wire terminal to the side