Ok I am interested in using IR detectors is this how I would need to use them for block detection and for detecting trains for the crossing gates? would this evn work to drive a signal analog signal controller?
yep - though youd need a light source on the other side of the tracks that the train would break.
if the ambient light works is bright enough, you might be able to place the detectors between the rails…
One of the manufacturers of IR detection devices for model railroading applications (can’t recall which at the moment) advertises that if your lighting is not bright enough, their equipment will not function properly. I would assume this serves true for any IR stuff. Someone told me that you can ballast over the IR detectors to some extent (between the rails) so they are hidden.
Thanks Dan and Smitty I wasnt grasping how they worked and if I was right I would have never aksed the stupid questions.
The questions are not stupid by any stretch. I have recently started looking into signaling and ran across quite a bit of good info. If you have the Walthers 2007 reference (catalog), that is a great place to find all this stuff in one handy place.
IR detectors will not work with normal light ( photo-cells will ). IR detectors need an IR emitter “to see”. That’s why IR detectors will work equally well in a lit or dark room as IR light is invisable to the human eye.
There are two common types of IR detectors - reflective and conductive. Reflective has the emitter / detector pair mounted beside each other and detects when the beam bounces off of an object within a given distance. Conductive sees the beam continually and relies on the beam to be broken by a passing object.
The reflective type works well mounted between the ties where it will reflect off of any rollong stock passing overhead. The conductive type needs the emitter and detector mounted facing each other across the rails so a passing train can break the beam. Both work equally well, however it’s sometimes difficult to camoflauge the above / beside track set-up.
Mark.
I have a set of mount under the track/ between the track detectors but I dont see how its gonna work or how I will even add them I got 1/2"ply with 2" foam and then woodlad scenics foam road bed on top of that.
Aha! I had it totally backwards (photo cell is correct). This is what I was thinking of…
http://www.walthers.com/exec/productinfo/800-5501
and this
Most common is to place detectors between track rails so trains will block room light.
Second, is a horizontal light beam or IR broken by rolling stack.
OTHER would be resistance detection, which is not IR.
I use side-looking IR LEDs and PhotoTransistors aimed across the track at the level of a flat car’s sides, and slightly offset to each other to allow for inter-car gaps.
I purchase mine in bulk from Mouser Electronics (http://www.mouser.com) and mount them atop a piece of Midwest Products 521-52, .118 x .233 Rectangular Tube.
Mouser stock numbers are 638-IR958-8C for the LED, and 638-PT928-6C for the PhotoTransistor.
I solder leads covered with shrink tubing to both devices and then connect them from below the layout. The LEDs will need resistors applicable to the voltage applied.
One approach I have seen work well is to mount the IR transistors underneath the tracks as mention several times above, but instead of attempting to find a place on the layout for the emitter, purchase higher power emitters and place them on the ceiling radiating downward.
Additionally, have you considered the use of current sensors for block detection?
If want almost hidden emitter / detectors, check out the board available from TCH Technologies …
It is a complete board with mounted reflective type IR pair mounted right on the board - only $7.95. The emitter / detector can be removed from the board for a remote locating of the board. Additional emitter / detector pairs can be purchased and wired in parallel so any number of tracks can be controlled from one board.
Mark.
Here’s also some good information on IR detectors … building / positioning / tips …
http://home.cogeco.ca/~rpaisley4/ATDetIR.html
Mark.
Milwhiawatha
You have the basic idea but you need two elements for the IR detectors. An emitter (IR light) and a detector.
I use a Berkshire Junction IR detector/controller for my crossing signals. The same basic system will work for signaling, though I believe that Berkshire Junction has specific kits and circuits for signaling.
The best part is that their systems are easy to install and relatively inexpensive.
There is a brief tutorial on the installation of my crossing signals on my website. Link is in my signature. Just push the How’d You Do that Button, then the thumbnail of the railroad crossing.
If you want to check out what Berkshire Junction has to offer her is the link:
[url=http://www.berkshirejunction.com]
Good luck with your quest.
First thanks to everyone who gave advice and Ideas. Allan your website was great and very helpful i will be checking those units out for myself. One question did you have the purchase the should module seperaretly.
For those who are looking for these, and are concerned about room/ambient light, MicroMark advertises these as “not affected by room lighting.” I don’t have any, I don’t know how they compare price-wise or functionally.
http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=83232
http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=83233
Has anyone else used these?
FT
Milwhiawatha,
I purchased the crossing signals I used on the BRVRR as a kit from Berkshire Junction. It came with two IR detectors, two emitters, two flashing light standards with red LEDs, the appropriate wire and a circuit/control board. The only thing I provided was the power supply. In my case, an old ‘train set’ power pack. The instructions were clear and easy to follow. The whole thing cost about $50.00 if I remember right.
Check out their website. They have more than just the crossing signals I purchased. An e-mail to them outlining what you want to do would probably result in a parts list, estimated cost and probably installation instructions/suggestions. A phone call would probably yield the same information, first hand.
Thanks for the kind words on my website. It is still a work in progress.
Good luck,
Those detectors on the Micro-Mark site are the exact same ones TCH Technologies sells … only the Micro-Mark ones cost 3 X as much !!! Pays to search around.
Mark.
I have the same thing, works great.