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system : IR sensor
Infrared Sensor
I use an integrated infrared sensor,
S4810, manufactured by Hamamatsu. I have bought it from Elfa.
Their article number is 75-223-03. This sensor is very small, and it gives out a clean logic level.
It needs a 4.7 k pull up resistor, and a
decoupling capacitor is also recommended. I mount these three components on a small circuit board, that
I place under the track. My solution is made for Märklin M tracks,
because that is what I use on my layout,
but it will work also with K tracks and 2-rail DC tracks. Märklin
C tracks will need some other solution.
Schematic
Figure 1. Sensor board schematic.
Pictures of the sensor board
Figure 2. The sensor board.
When mounted under an M-track, the sensor looks up through
one of the holes for the center rail.
Figure 3. The sensor board mounted under an M-track.
Layout
My friend and colleague Stefan Eskilsson helped me with
designing the layout. A PDF drawing of the layout can be found here.
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: Train recognition system : IR sensor
Last edited August 10, 2012