Here is a way to use old wire coat hangers to make simple and efficient wiring harness guides that can help keep your layout wiring neat and tangle free.
The guides allow individual wires and small cables to be fed in without them becoming wrapped around other wires. Also the wires do not have to be fed into the guides in series from one guide to the next along the run. The entire length of wire could be run out and then fed into the loops in any order and in either direction.
As the guides are made from old coat hangers they are inexpensive and could easily be made on a simple jig. Once layout wiring is complete (not a likely prospect) they can be replaced by more permanent anchors or left in place.
One end of the coat hanger wire is filed to remove any burrs or sharp edges. This will be the end on the inside of the loop.
A 1-1/4 turn loop is formed around a rod or piece of pipe held in a vice. When the wire is released the wire will spring out and the loop will increase in diameter and shorten in length slightly.
When the loop is finished the turns may have to be expanded to allow the largest diameter wire used to pass through the gap between turns.
A space will have to be left between the mounting surface and the bottom of the loop so that the wires can pass underneath in order to reach the gap at the back of the loop.
A small eye is then formed at the end of the wire to allow the guide to secured to the layout with a screw.
When the eye is finished it is bent at a 90 degree angle to allow the loop to stand perpendicular to the mounting surface.
The following pictures show coat hangers being used to mount Infrared LEDs. The LEDs a being used to provide light for photoransistors that are are located in dark areas.
the wire can be bent into any shape desired with the eyes at each end sized to snuggly hold the LEDs and pass the desired mounting screws. The wires soldered to the LEDs are held in place with small sections of heat shrink tubing which was left at its original size.
The holder is screw nailed to the underside of the benchwork and shines on the sensor placed between the rails.
The 45 Degree bend in the above holder allows the LED to illuminate a phototransistor that is not near the edge of the road bed.
The upper holder has the mounting tail bent so that it could be secured to the bottom of the benchwork while the lower holder can be placed on top of the benchwork.
The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.
If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.
Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.