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Optical Train Detection

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Optical Train Detection
Posted by PennsyLou on Sunday, March 20, 2022 9:09 AM

I have a hidden (lower level) 6-track staging yard where I need to install some sort of optical train detection system that will work under low-light conditions (i.e. Infrared).  Two sensors per track are envisioned - one to show the train has cleared the ladder (fouling point) and another to detect the approach to the end of the track.  It appears that the IRDOT in its various iterations is no longer available (i.e. Micro-Mark) though there are some on EBay for $$$, while there appears to be a plethora of detection circuits available from various sellers but it is hard to gauge which of these would be most appropriate for my application.

What do people without an advanced electronics degree use nowadays for optical train detection?  I am reasonably competant with electronics, but would also prefer a "plug and play" alternative as there is plenty of other stuff that I'd rather spend my time on.

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  • From: Bedford, MA, USA
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Posted by MisterBeasley on Sunday, March 20, 2022 11:05 AM

Not exactly what you're looking for, but I installed a couple of Rob Paisley detectors for crossing signals and gates.  As designed and ultimately installed, they were quite plug-and-play and work perfectly.  With his help, I switched to infrared lights and detectors for night operation, but gave up on that for surface application because the room still remained too bright.

He might have a simple circuit you could copy.

It takes an iron man to play with a toy iron horse. 

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Posted by RR_Mel on Sunday, March 20, 2022 11:28 AM

I went with the Arduino Obstacle Detection Sensor Module FC-51.  They work off reflection from rolling stock or locomotive up to about 6”.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=+5x+IR+Infrared+Obstacle+Avoidance+Sensor+Module%60For+Arduino+Smart+Car+Robot+Fad&_sacat=0

They can be used to turn on a LED on your control panel.

Mel


 
My Model Railroad   
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Turned 84 in July, aging is definitely not for wimps.

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Posted by gregc on Sunday, March 20, 2022 1:07 PM

PennsyLou
I have a hidden (lower level) 6-track staging yard

there are type types of optical dectection methods: direct and reflective.

i believe what Mel suggested are the reflective type.   some surfaces are less reflective than others and the detectors may be sensitive to room or sun light

the direct type dectect something when it breaks the beam between a light source and detector, and i believe more reliable and less complicated.

since you mentioned hidden, i assume you could mount a IR light source above the tracks and detectors in the tracks.   an IR light source is an LED.  so an emitter and resistor.

the detectors are transistors that stop passing a current when the light source is blocked.

you can probably use what Mel suggested with long wires connecting the emitters and detectors.

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Sunday, March 20, 2022 2:19 PM

Greg

You can remove one or both of the sensors to use it as a beam break but that reverses the output.  For the price of the FC-51 modules you can’t go wrong.

When used as a beam break it extends the distance to over 10’.

I have approximately 50 of the FC-51s used reflective and if used at 2” they detect all colors.

I mounted them at tunnel portal clearance above the track in my tunnels and I haven’t had any miss detection of anything.

I have a bunch with the sensors between the ties with the focal point .4” above the rail that catch everything.





Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

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Posted by ndbprr on Sunday, March 20, 2022 7:08 PM

Why not use somethung like a gopro camera to a computer and align the trains visually?

  • Member since
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  • From: Collinwood, Ohio, USA
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Posted by gmpullman on Sunday, March 20, 2022 8:40 PM

I'm in the video CCTV camera camp. I first installed a low-budget setup when Electronics Surplus had cheap B&W cameras available for about $15 each. I've since upgraded with other cameras found on eBay or Amazon.

 Sydney_east by Edmund, on Flickr

The numbers on the joist above can be seen in the camera monitor for my reference:

 Sydney_clear by Edmund, on Flickr

I'll have to get a screen capture directly off the cameras later. They have built-in IR illumination so I can see what's going on even in total (visible) darkness.

Good Luck, Ed

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Posted by mvlandsw on Sunday, March 20, 2022 11:48 PM

If you use optical detectors you might consider using two at the head end of the train. One will tell you when a train approaches the end of the track but you can't tell if it has proceeded far enough past the detector to foul a switch to another track.

If your tracks are used in both directions I would use two detectors at each end. One should be about six inches from the fouling point and the second at the fouling point. The train should be stopped when the first detector is triggered. If the second one is not triggered you know that the train is in the clear.

Mark Vinski

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Posted by ba&prr on Wednesday, March 23, 2022 2:34 PM

 Maybe this? https://www.iascaled.com/store/CKT-IRSENSE

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Posted by RR_Mel on Wednesday, March 23, 2022 3:42 PM

You can get quite a few FC-51 modules for the price of one CKT-IRSENSE

https://www.ebay.com/sch/i.html?_from=R40&_nkw=IR+Infrared+Obstacle+Avoidance+Sensor+Module+for+Arduino+&_sacat=0&_sop=15&rt=nc&LH_PrefLoc=1

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

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Posted by DigitalGriffin on Thursday, March 24, 2022 8:17 AM

RR_Mel

You can get quite a few FC-51 modules for the price of one CKT-IRSENSE

https://www.ebay.com/sch/i.html?_from=R40&_nkw=IR+Infrared+Obstacle+Avoidance+Sensor+Module+for+Arduino+&_sacat=0&_sop=15&rt=nc&LH_PrefLoc=1

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

 



Now I'm going to have to explain to my wife "why I have another package coming in the mail." Big Smile

Usually I create my own CT Coils and measure occupanacy through current use.  But for spot occupanacy, this is a good idea.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by RR_Mel on Thursday, March 24, 2022 9:51 AM

According to Digikey my 0603s should be here tomorrow.

Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
Turned 84 in July, aging is definitely not for wimps.

  • Member since
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  • From: Edgewood, WA
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Posted by 2ManyHobbeez on Thursday, March 24, 2022 9:54 AM

If you are running JMRI my wheel counter will work.

https://youtu.be/XXx7MxsFI0o

George

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