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Resistor wheelsets for occupancy detection
By Steven Brown
By Steven Brown
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Now that you have the components, it is time to start gluing and painting. To make the process go faster I do several cars at each step. Doing it this way also builds in drying time for the conductive glue.
1. Empty a small amount of super glue and accelerator onto two pallets. Start by dabbing a small amount of super glue onto the center of an axle using a toothpick. Using tweezers, dip the resistor in the accelerator and place onto the axle. The glue should set up almost instantly.
2.Next take the conductive paint, making sure it is well mixed, and paint from the metal on the inside back of one wheel to the small metal tab on one side of the resistor. Do the same from the other side making sure you do not accidentally paint all the way across the resistor.
3.After you let the conductive glue dry for a few minutes, check the resistance of the axle by measuring across from one wheel to the other wheel across the axle. Anywhere between 10K and 20K ohms will work.
That’s it. You now have all your rolling stock equipped with resistors that will allow them to be detected on your railroad.
1. Empty a small amount of super glue and accelerator onto two pallets. Start by dabbing a small amount of super glue onto the center of an axle using a toothpick. Using tweezers, dip the resistor in the accelerator and place onto the axle. The glue should set up almost instantly.
2.Next take the conductive paint, making sure it is well mixed, and paint from the metal on the inside back of one wheel to the small metal tab on one side of the resistor. Do the same from the other side making sure you do not accidentally paint all the way across the resistor.
3.After you let the conductive glue dry for a few minutes, check the resistance of the axle by measuring across from one wheel to the other wheel across the axle. Anywhere between 10K and 20K ohms will work.
That’s it. You now have all your rolling stock equipped with resistors that will allow them to be detected on your railroad.
Most occupancy detection systems for model railroads detect a train by measuring the electrical current going to a section of track. Normally, the locomotive is the only piece of equipment that draws power. Therefore, the engine is the only part of your train that the detection system sees. That is a problem because your train could still be occupying a block or turnout and the detection system would think that nothing is there.
To solve this problem, you need a way to detect every piece of rolling stock on the layout. This can be done using resistor wheelsets. You can buy resistor wheelsets readymade but they are expensive and a little oversized. The best and most economical solution is to do it yourself. This is easy and you can convert all your rolling stock in one evening. All you need is rolling stock with metal wheels and the following supplies:
To solve this problem, you need a way to detect every piece of rolling stock on the layout. This can be done using resistor wheelsets. You can buy resistor wheelsets readymade but they are expensive and a little oversized. The best and most economical solution is to do it yourself. This is easy and you can convert all your rolling stock in one evening. All you need is rolling stock with metal wheels and the following supplies:
-10K surface mount resistors (1206 size)
o These can be ordered from Jameco Electronics or a similar electronics supplier. They are usually ordered in multiples of 100. Good thing they only cost $0.009 a piece! Remember you are going to need at least one on every single car you own so don’t worry about ordering a lot.
-Conductive glue
o This is really a paint that can conduct electricity. You can buy this from All Electronics in a small 0.3 fl. oz. bottle for $3.98. I’ve done several hundred axles so far and I’m still on my first bottle.
-1-3 Second CA Adhesive (the light blue cap) or a similar type of super glue
o These can be ordered from Jameco Electronics or a similar electronics supplier. They are usually ordered in multiples of 100. Good thing they only cost $0.009 a piece! Remember you are going to need at least one on every single car you own so don’t worry about ordering a lot.
-Conductive glue
o This is really a paint that can conduct electricity. You can buy this from All Electronics in a small 0.3 fl. oz. bottle for $3.98. I’ve done several hundred axles so far and I’m still on my first bottle.
-1-3 Second CA Adhesive (the light blue cap) or a similar type of super glue
o This you can get at any hobby shop if you don’t have it already.
-Insta-Cure Accelerator (small spray bottle)
o As with the CA, you can buy this at your local hobby shop. The accelerator is not completely necessary but I am impatient so I used it.
-A meter that can measure resistance
-Insta-Cure Accelerator (small spray bottle)
o As with the CA, you can buy this at your local hobby shop. The accelerator is not completely necessary but I am impatient so I used it.
-A meter that can measure resistance
Written by Steve Brown in cooperation with the Central New York Modelers Railroad Club.
Preceding article and images are solely intended for private use unless expressed permission is given.
6 May 2011 All Rights Reserved
Preceding article and images are solely intended for private use unless expressed permission is given.
6 May 2011 All Rights Reserved