Train detectors

Garden Railroading
1

[:D] Hi all,

It’s me again Dennis from New zealand.

What sort of detectors do you use on your layout that will trigger a relay for example going into a reversing loop? As an electrician i like using relays and double pole switches, rather than electronics.

Thanks looking forward to hear from you all.

Cheers Dennis.

2

Well… Being somewhat of a simple minded person! I use a magnet and a reed. As the train passes over the reed it connects and triggers the relay (for a signal). I did improve this with an “end of train” detector using an LDR Light Dependant Resistor. As the train goes over the LDR -it gets dark! When the train has passed over the LDR -it gets light again! This then provides enough current (10mA) to trigger a reed relay. regards ralph

3

Hi Ralph,

Thanks for that, I was thinking on the same lines as that , i wonder if any one else has?

Cheers Dennis.

4

light detection outside can present a few problems with dirt and dust and obviously will not work at night

magnets are probably best outside but whatever seems easiest i guess - just make sure all joints are soldered and double heat shrink wrapped

5

Thanks Dave, I agree.

cheers Dennis.

6

You could use IRDOT type - which have infrared emmitter/receiver packages but to my knowledge no one has got this working succesfully outdoors

http://www.heathcote-electronics.co.uk/index.htm

7

Happy New Year

I have very low voltage high tor. motor.

The frog arm also operates a slide dpdt switch.

You could also use Microswitches with a roller arm.

with a dpdt micro you do not need a relay.

Major tip. place the switch so that the slider goes with the switch arm and not aginst it.

Have Fun

Spike

8

Hi Spike,

Thanks for that

Cheers Dennis

9

i have nothing like that, but i would not use a light detector of any sort, because it is my opinion that it would look very unrealistic. i myself would use either a magnet and reed or a pressure switch.

Pilot4996

10

ERRRMMM…

" i have nothing like that, but i would not use a light detector of any sort, because it is my opinion that it would look very unrealistic. i myself would use either a magnet and reed or a pressure switch."

The LDR I use is 3mm across -about the same size as fish tank gravel, it is sat in a hole drilled in a sleeper -thus it cannot be seen. A glass reed switch is a minimum of 10mm long -or three times the size, this is also sat in a channel chopped into the back of a sleeper and also cannot be seen. Pressure contact switches do not work if you do not use track power -something the wet cold Peak District renders nearly impossible…

I have read some of the comments in this thread with quite frankly the thoughts -“what have these people been drinking?”

I particularly LOVE the one that said that an LDR would not work at night, this is true, but how many people play trains at night in sub zero temperatures??? It also will not work when the ground is covered in four feet of snow -as it was 2 weeks ago.

I design liquid cooled computers for a living. I use LDRs to examine the quality of the coolant Sulphur Hexaflouride by the simple method of having a light shine through it and the amount of particulate matter as it rises stops the light shining on the LDR -thus triggering the alarm. If I rely on this simple method to protect computers starting at around £3.5 million I feel confident that it will continue to work on my simple loco and wagons…

regards

R.M. ben Brades B.Ed B.Sc M.Sc M.I.A.A.P. Ph.D

11

Hi Crew: re: the unrealistic look of Track side Detectors. Hear is a real world morden Track/Train Detectors, and using some of the very things that you guys are trying to Implement on your rail systems, :smiley:

I think that ‘cabbage’ has the Right Idea: KEEP IT SIMPLE :slight_smile:

Photo and info on all detector devices that are in or on the sleepers:

http://www.onrgallery.com/preview0551.html

cheers Greg.