W9YA Elegant Launch Controller

The Rocketeer's favorite Launch Controller System


Begin construction by testing for parts fit and placement. Now is the time to make sure you have sufficient mounting hardware and that the parts will fit where you want to place them. Besides the usual hand tools a dremel tool will come in VERY handy for mounting the duplex electrical socket. The outlet cover will cover any minor imperfections in the cutout you make. Take your time with this part of the construction as the results will last a long time.

The wiring diagram is a standard electrical schematic. Dots indicate electrical connections with lines to indicate current paths and the boxes are for the buzzers. The switches are indicated by the disconnected lines between two (or three dots with a perpendicular dashed lines going through the center of the three dots). The solid line in each switch is what is known as the 'Normally Closed' (NC) position. The other is known as the 'Normally Open' (NO) position. The other dot is called the 'Common" connection. The relay has two parts, the coil indicated by the circular lines that kind of look like a coil of wire with two lines immediately adjacent to the coil to represent the coil's magnetic core material, and the relay's switch is indicated much like the other switches except the dashed line extends to the coil's two horizontal lines. The diodes are marked with a band to indicate the cathode or banded side of the device. On the schematic the diodes look like this band touching the point of a filled in triangle. Removable connections (like the electrical cord and socket) are indicated by the arrows made from two small lines. The fuse is indicated by a wavy line. The two triangles with 'AA" inside of them represent two places in the circuit that are connected together. The other two triangles with 'BB" indicate another two places on the schematic that could not easily have had a line drawn between them.

The 12 position terminal strip is used to allow connections between various parts. There are two rows of 12 screw heads. The wiring is inserted under the screws which clamp down on the wiring to secure a stripped piece of wire, or a bare component lead (such as the diodes). In some cases, such as the large number of connections to the battery negative pole, various tie points like the safety switch studs and the test switch's common stud could be used to facilitate more than one piece of wire. The idea is to have the wire (or a part of a switch,) between any dots that are connected by a line. Tugging and stressing these screw-based connections now will save hours of time later troubleshooting intermittent connections.

The duplex outlet can be used in two different ways. Nominally you can use it for two sets of igniter leads. Used this way the ground lug is not used at all as the igniter leads should be wired to just the hot and neutral of the two conductor plug. Cutthe 50 foot extension cable into two pieces with the cut being made 10 -15 feet from the socket (female) end. This gives you a male end coming from the Remote Unit and the female end going into the Relay/Pad Unit.

The other way to use this outlet is to break the 'link' between the two outlets hot connector screws. Doing this allows you to use one of the outlets as the input from the cabling connected to the Remote Unit. In this case you will be using the ground connection as indicated in the schematic diagram.

A few of other things about the construction phase you will need to know. The LEDs (light emitting diodes) in the toggle switche(s) **must** be removed for proper operation. I just took off the shaft cover and yanked them out. If you forget to do this, you will find the unit does not operate correctly even though everything else is correct.

I also elected to use crimp terminals and lugs of various sizes to avoid the use of solder and yet assure clean and neat connections. If you decide to use crimps be sure to tug hard on each one after you make it, as it is easy to create 'intermittent' connection problems that are hard to troubleshoot later.

Be sure to orient and wire the toggle switches with the covers so that closing the cover disarms the each unit. This is a safety issue and should NOT be changed.

Rocket Graphics courtesy of the Crystal Space Community.