# scratch build crossing guard



## Blk69 (Dec 6, 2009)

Not sure if this is correct place to post this, but thought I would start here at this forum.

I am building my first outdoor layout and would like to add a guarded crossing. Planning something simple, couple of flashing leds on RR placard (one each direction of roadway). Don't understand the magnet activation seen on web so planning on putting in a couple of photeye on each side of crossing. Will put them in parallel to allow train to clear keeping lights on (two photoeyes need so train can travel both directions activating guard).

Has anyone scratch build a system like this with a controller? If not I will plan on posting my process. Anyone recommend a good supplier for outdoor photoeyes? Not sure if I will post above tracks (to side) or inbetten sleepers. Prefer sleepers, but may be difficult to keep eyes clean (horizontal mounting). Thinking will build a simple flasher controller instead of using flashing LEDs. This will allow some control on flash rate. Thinks around 1 second flash should be good. May alternate flashing LED (one flashes, then the other) for more dramatic effect.


----------



## Blk69 (Dec 6, 2009)

Ok, watched a few youtube clips. Will be adding a bell. Moving guards are cool, but concern over moving part with outdoor layout. Will stick to flashing signals only.


----------



## jimtyp (Jan 2, 2008)

If you do build your own I'd be interested in the how-to, as I'd like to do the same for my layout.


----------



## dieseldude (Apr 21, 2009)

Ditto that. Post your progress. Pics would be cool, too. 


-Kevin.


----------



## Greg Elmassian (Jan 3, 2008)

Note that outdoors, ambient light can confuse these unless you take steps. 

I'd use an IR diode as a transmitter, beaming across the track to a receiver, just a phototransistor. Putting between the ties would expose the receiver to the sun, not usually a good idea. 

You might be able to buy the components from Digikey, or Mouser, but I believe you need a circuit. 

Look for Dave Bodnar at trainelectronics.com he has lots of good ideas. 

Also, Todd Allen (sp?) should be around, he's always got a circuit up his sleeve, so to speak. 

Greg


----------



## toddalin (Jan 4, 2008)

You don't need a "photo-eye." All you need is a pair of "track gaps," a relay, a capacitor(s) and either a rectifier/voltage regulator or wall wart.

The metal wheels crossing the track gap trip the relay and the capacitor holds the relay closed for any pre-determined length of time. The relay can be used to power whatever you desire. The regulator or wall wart should match the voltage of the relay and the capacitor should have a slightly higher voltage capacity. 

I have found that three 6 F supercaps in series (2 F @


----------



## Blk69 (Dec 6, 2009)

I am unfamilar with the term "track gaps"? Is this just a small space beween two electrically isolated sections of track? 

Would perfer to place activator between sleepers of track for astictics and protection of sensor. Did not think about the sun messing things up. I have kids so my layout will be subject to them as well as the normal assortment of Gods creatures. See it difficult to keep sensors alined about tracks. 

In my O gauge layout, I just use the weight of the engine to activate a crossing. Maybe I can do something similar outdoors?


----------



## toddalin (Jan 4, 2008)

Exactly. I use a small section of rail between two AristoCraft or LGB insulators. CliffyJ uses an insulated section made by Split jaw or such.


----------

