This device is used to supply large amounts of current to large clusters of motors with high current igniters. It can be easily be moved to any pad (especially when mounted inside a .50 cal or smaller ammo box which will hold the heavy igniter leads and battery cable).
The igniter clips from your existing 12 volt launch system are attached to the two posts on the device to power the coil on the high current relay. Starter solenoid coils demand up to 10 amps for the coil. So, to use this device, your existing system should be capable of supplying that current.
The "cluster buster must be also be attached to a car battery or other high current source. Starter solenoids attached to car batteries are capable of supplying up to 120 amps if the wire size is appropriate. I use heavy duty battery jumpers. You can run heavy wire to the pad and split it off the igniter wire into multiple wires at the end if necessary. Each of the smaller wires must be large enough to handle the current of the igniters to which it is attached.
The resistor and LED shown in the schematic below may be omitted if continuity display is not desired but it is sometimes helpful even for clusters.
If your existing system uses solid state devices SCRs or LEDs, the 1N4004 (a 400 volt diode) will be necessary to the protect launch system from voltage spikes produced when the field around the coil collapses as it is de-energized. If the spike protection diode is used, then polarity must be observed when connecting the leads from the existing launch controller to the posts.
Perhaps the most important key to successful large scale clustering is keeping the igniters inside the motor during ignition. This can be accomplished by securing each igniter wire to motor retention screws etc. so that the igniters are not pulled out as the rocket launches. Generally, the igniters are wired in parallel. The igniter wiring from the controller is secured to the launch pad but should have enough slack to allow the rocket to travel up the launch rail a significant distance before the controller wiring is pulled loose from the connection points on the rocket.
Make a good connection which will not come loose until the rocket has moved up the rail but do not tie the igniter lead connection to the igniter clips, If the connection is too secure, it can cause a mid-course correction as the rocket leaves the rail and is jerked by the wiring. Or, the rocket can take the igniter whip with it unintentionally.
Other tips include using aggressive igniters to insure rapid pressurization of the motor. This is less an issue on fast propellant like Blue Thunder. It is also helpful to use igniters which fire immediately on reasonably low current. Long burn igniters work provided they are retained inside the motor. But, more aggressive igniters help insure simultaneous ignition of all the motors.