Robert Frey
Website: http://bobfrey.auclair.com
Slowly building a layout since 2007!
My Digi-Key Part Search: http://www.digikey.com/
Article by Rangachari Anand October 26 2007
http://www.coralfringe.com/IRDetection.html
His experiments in using IR to detect HO train occupancy.
IR Emitter is QEC113 Fairchild Optoelectronics Group Digi-Key Part is QEC113-ND
“A cost-effective way to utilize IR detection on a train.”
rxanand Here is the link: http://www.coralfringe.com/IRDetection.html
How's that?
The mind is like a parachute. It works better when it's open. www.stremy.net
Three albums of photos from the streets of Hyderabad in India by Rangachari Anand
http://www.coralfringe.com/
He also made reference in his article to IRDOT detector from Micro Mark.“Standard IRDOT-1 mounts to underside of track base board.Emitter/detector pair installs through hole drilled between ties. Trains passing overhead reflect the beam and trip the circuit.”
http://www.micromark.com/SearchResult.aspx?deptIdFilter=0&searchPhrase=IRDOT
www.logicrailtech.com I like the stuff they have and simple.
http://www.logicrailtech.com/sigani.htm
Robert FreyYes, Logic Rail Technologies does make easy to use Optical Detectors.
Quite a difference in price between this commercial product and your two designs isn't it? Will your design work just as well?
By substituting a 2N3904 transistor for the more expensive and hard to find MPSA27, I have gotten Robert's circuit to detect up to 2 inches away.
QRB1114-ND (SENSOR IR NPN) is $12.29, MPSA27GOS-ND (TRANS NPN DARL) is $3.18, P470KCACT-ND (RES 470K OHM) is $1.71, RNF1/4T1470FRCT-ND (RES 470 OHM) is $1.05 P680CACT-ND (RES 680 OHM) is $1.71, 511-1250-ND (LED 3.1MM RED) is $3.17, Shipping U.S. Postal is $4.80, Sale Tax is $1.16, Your ONLINE ORDER Total is $26.
DALLEE ELECTRONICS Infra-Red Optical Detection #552/553 http://www.dallee.com/Optical_Detector.htm
Ram Track Electronic Devices http://www.ramrcandramtrack.com/ramtrkbro.pdf See page 4 of 6 pages
See page 4 of 6 pages
RAM 102 INFRA RED SWITCH. This system uses infra red. For convenient, trackside installation, the IR sender and receiver are each on 1 foot cables attached to the circuit board and powered by 5 to 24 volts D.C. Regards,
RAM 102 INFRA RED SWITCH. This system uses infra red. For convenient, trackside installation, the IR sender and receiver are each on 1 foot cables attached to the circuit board and powered by 5 to 24 volts D.C.
I had posted some remarks earlier in this thread. I have several update on my experiments with IR sensors:
I was just looking at Rob's octal circuit. I'd need to add a bit of additional logic on the output to do what I was planning. I have 2 staging tracks at each end of my layout, each track is more tahn double the length of a typical train, so I was plannign to allow doubling up. Since there is absolutely no way to actually see the staging tracks without removing the removable backdrops, I want to have indicators on the fascia. My idea was to have a green light for each half track that is on when NO train is there. At the clearance point would be a sensor to trigger a yellow light - so as the train starts to enter the track, the green light goes yellow. At the stopping point would be another sensor that turns on a red light so you know when to stop. So - track has a green light, line the switch for that one. As you enter the track, yellow light goes on. AFter you are clear the yellow goes out. When the red comes on, stop.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi Randy,
Question is 2 staging tracks at each end of layout, each track is more double the length of a typical train.
Answer is Five IR sensor in each staging track. Example Train 1 enters staging track 1. Color is Red then Yellow then Red then Yellow then Red. STOP! (End of track is now Yellow off & Red on.)
Train 2 enter staging track 1. Color is Red then Yellow then Red. STOP! (Beginning of track is now Red off, Yellow on, and mid. Red on.)
The basic idea is Begining, 1/8, 1/2, 5/8 and full. STOP!. (If the Begining is on, then the turnout is not clear.)
Regards,
See, I figure I can do this with just 4 sensors per track. Repeating the same example:
Track 1 is empty. 2 green lights. Train enters. Yellow A comes on..keep going. Red A comes on...Green B is on so keep going. Yellow B comes on. Red B comes on - STOP. Second train comes in. Green A is on, RED B is on because a train is in the back half. Yellow A comes on, kee going. Red A comes on - STOP.
--Y------------------------R-----Y-----------------R-| sort of like that. Green LED would be driven by a NOR gate from the yellow and red - when neither one of those is on, green is lit. Only downside is a short train will turn on the green after the yellow goes out but before the red lights. Easy to take care of by rule: always run your train into the siding until the red light comes on. Or since I plan to use track detection for signals on other partsof the layout, I could add in the signal from a detector in each half of the siding. Seems like overkill to keep a spurious green light off. Option 2, use some sort of IR sensors as shown to feed a PIC or Atmel chip with simple coded logic to activate the LEDs. Gives me an excuse to play with a PIC.
OK Randy, just 4 sensors per track. But remember, when your two Red sensors are on, both Yellow sensors MUST BE OFF. Regards Robert Frey
PS: I am going on vacation for 2 weeks.
Yes - that's the sanity check. If the red comes on before the yellow goes off, your train is too long.
Which means you probably picked up one too many cars, or forgot to set one out.
Doing this with a PIC or Arduino is definitely one way to go about this. I just got an Arduino and am having fun exploring model railroad uses. However, I would suggest that you look into JMRI and investigate the possibility of doing this in software. You may already be using DecoderPro for programming your decoders.
Anand