Movement detector?

[Monty]

Has anybody come across a suitable movement detector to indicate with say an LED when a loco or wagon etc has reached or passed a certain location? My layout exit to the fiddle yard is a little hidden & I was wondering if there was something available to show me when something has got to the exit. I guess the LED could be lit all the time but goes out when something reaches the desired location or either lights up when something passes that same point.

[nigelcliffe]

Beam-breaking IR detector would seem to be pretty simple - needs a transmitting IR LED and receiving device. Plus power and an indicator (a visible LED) somewhere. Just check that the beam is broken by your stock, some plastics can be transparent to some wavelengths.

Typical components need a 5v DC power supply in the vicinity, and excluding power supply, the whole lot ought to cost less than £5.


- Nigel

[Monty]

Just wondering if there was a nice little kit about!

[Alan Turner]

Just wondering if there was a nice little kit about!

Yes but you have to join MERG. They do a few including a LASER detector.

Regards

Alan

[dal-t]

I've got an annoying little motion detector that came in the form of a cheap rechargeable torch cum emergency light. It sits plugged into it's charger in a power socket, from which it can just be lifted out if you want a torch, but it also comes on automatically if there's a power cut. Ideal for our guest quarters, I thought, because it can get pretty dark here in rural France )particularly if the shutters are down) and the power does go off from time to time. But if you move with the room light off, it also comes on - and then takes a variable amount of time to go off again, probably depending on its battery state. If I had a 'hidden sidings' requirement I'd be very tempted to take a large hammer to the plastic case of this little beast, and see what the innards could offer me. The only trouble is, it might well want mains voltage (even at something a bit less than 220V).

[garethashenden]

I haven't used these personally, but there seem to be lots of options: http://www.azatrax.com

[grovenor-2685]

Unless you operate in the dark light dependent resistors (LDRs) work from the ambient light and fit nicely between the sleepers detecting anything passing over putting them in the shade. The MERG pocket money kits have these detectors for £0.88 each including an LED for the indication.
The circuit only needs 1 transistor and a couple of resistors all included.
Rgds

[Terry Bendall]

Circuits using a light dependent resistor have been around for many years. I was teaching 14 year old children how to built such things 35 years ago and a bit of on-line research or even find a book will show what is needed. No need to join MERG although they have some good ideas for those who have the inclination.

Terry Bendall

[SteamAle]

Why not CCTV? Cheap dash cam and a small monitor will let you see the actual train rather than just an indication that 'something' has tripped a switch/beam.
Philip (thinking outside the box!)

[Terry Bendall]

Why not CCTV?

Circuits using a light dependent resistor have been around for many years

Why make something simple when with a little effort you can make it complicated.

Terry Bendall