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Indication and alarm of Turnout status

Posted: Thu Nov 25, 2021 9:43 am
by gregh
After many months of ‘carpentry’ eradicating the termites and rebuilding my train room, I decided a bit of electronics would be a change and maybe get the grey cells working.

The new track arrangement in my train storage room (called Termite) has 4 sidings leading off the reverse loops. If a turnout is left open to the siding, and a train run in around the reverse loop the train can finish up in the buffers of the siding, or worse, hitting other trains in the siding.
Of course I myself would never leave the turnouts set for a siding :) , but maybe visitors or my grandsons might.

So my first idea was to just put an indicator light on each turnout with a bright red LED.
Then I thought an audible alarm would be useful to remind operators outside the room not to let their train enter.
And then after a near miss, I realised that the wagon storage drawer could be left fouling the mainlines. So another alarm was called for.

To detect the state of the turnouts, I used a photo-detector. It just requires 2 resistors and the LED in addition to the photo-detector.
A piece of plastic glued to each turnout tie-bar slides in the optical slot to block the beam and turn on the red LED.
detector installed.jpg
detector installed.jpg (373.86 KiB) Viewed 4236 times

An alarm is also triggered by each turnout and sent to a common alarm board which uses a picaxe (micro computer) to sound the alarm softly for about 20 seconds and then go loud until all alarms are reset.
There is also a Light Dependent Resistor (LDR) to detect when the drawer is fouling the main line and it connects to the alarm.
alarm cct installed.jpg
alarm cct installed.jpg (420.89 KiB) Viewed 4236 times

And a video of the operation might be easier to follow..

Re: Indication and alarm of Turnout status

Posted: Thu Nov 25, 2021 9:53 am
by ge_rik
Ingenious, Greg. That buzzer would sure make me want to reset the points to shut it up ..... :lol:

Rik

Re: Indication and alarm of Turnout status

Posted: Tue Nov 30, 2021 9:57 pm
by Lonsdaler
That's a really ingenious solution - I'm not sure it would be weather resistant enough for my all outdoor railway, but some method of making drivers aware of point settings would be useful.

Re: Indication and alarm of Turnout status

Posted: Wed Dec 01, 2021 5:23 am
by philipy
Lonsdaler wrote: Tue Nov 30, 2021 9:57 pm I'm not sure it would be weather resistant enough for my all outdoor railway, but some method of making drivers aware of point settings would be useful.
That is exactly why I built my 3-way signal some while ago.
https://gardenrails.org/forum/viewtopic ... ls#p138315

Re: Indication and alarm of Turnout status

Posted: Fri Dec 03, 2021 1:39 pm
by Lonsdaler
philipy wrote: Wed Dec 01, 2021 5:23 am
Lonsdaler wrote: Tue Nov 30, 2021 9:57 pm I'm not sure it would be weather resistant enough for my all outdoor railway, but some method of making drivers aware of point settings would be useful.
That is exactly why I built my 3-way signal some while ago.
https://gardenrails.org/forum/viewtopic ... ls#p138315
Thanks for reminding me of this Philip - bookmarked but forgotten🤦‍ Maybe a suitable winter project. Is it still functional? I assume so!