motion detector

[Steve Redford]

Hi all

 

I am looking for a low cost 'motion detector' switch, which would after a delay return to 'closed. Maplin sell a motion detector kit, but I wonder if anyone has used anything that a loco could trigger as it passes over a part of track.

 

Thanks

 

Steve

[Black Sheep]

A light sensor broken by the train as it passes could do the job?

 

the other option would be to have a microswitch under the track that the weight of the train triggers, you'd need some sort of program circuit to sort out a delay.

[43110andyb]

Heathcote electronics do the IRDOT range of Infra red sensors. What is it to be used for?

 

 

[Kenton]

Heathcote electronics do the IRDOT range of Infra red sensors. What is it to be used for?

I can recommend these from personal use. They come with optional delay timer and on board relay. Fit below track baseboard and peer out through the sleepers or in roof of tunnel pointing down. When the train passes over they are triggered. Should cover just about every application and require no soldering or knowledge of electronics.

[Steve Redford]

thanks

 

Yes am aware of Heathcote IRDOT and I have many applications where their usage could be applied. I was just thinking of a very cheap,cheerful and simple switch activation as a train passes. I want to trigger a sound device in the station as the train approaches. I guess I could also use a magnet and reed switch. The reason for the delay is it is activated for 10 secs and then released ( if you follow my drift)

 

Thing is - I am in a period of prototype and investigation as I want to have a pretty automated system eventually and have written about signal operation on other posts with either the IRDOT or perhaps a decoder like the one from traintronics. However, I also like the idea of loco's have ids specific to them so that different things happen according to the loco and route. ( I know why can't I just have a simple life!!) So, I have also been looking at GPS, but I don't know how this would feed into software like Railmaster for example.

 

I want to have the options to control almost everything as simply as possible and have fun constructing it all.... ( well its better than digging the garden in the rain)

 

Steve

[hollywoodfoundry]

Steve, an IRDOT is about as simple as you can get, and it is very reliable. Magnets and reed switches are messy things to get going properly and not particularly reliable in operation.

 

If you want to have the locomotives uniquely identified, then perhaps you might look at RFID (Radio Frequency Identification). This is the same as the implanted chip used to identify pets, but applied to position control in model railways. The Model Engineering Railway Group (MERG) have some very interesting tutorials and information on this technique: http://www.merg.org.uk/

 

You will need to join MERG to obtain the information, but they also have kits for investigation of RFID: http://www.merg.org.uk/kitdetails.php?kn=1

[Steve Redford]

Thanks - that is very useful feedback.

 

Steve

 

 

Steve, an IRDOT is about as simple as you can get, and it is very reliable. Magnets and reed switches are messy things to get going properly and not particularly reliable in operation.

 

If you want to have the locomotives uniquely identified, then perhaps you might look at RFID (Radio Frequency Identification). This is the same as the implanted chip used to identify pets, but applied to position control in model railways. The Model Engineering Railway Group (MERG) have some very interesting tutorials and information on this technique: http://www.merg.org.uk/

 

You will need to join MERG to obtain the information, but they also have kits for investigation of RFID: http://www.merg.org....etails.php?kn=1

[Steve Redford]

It's the IRDOT-P that isues a 1 sec pulse to complete a circuit exactly as I want.

 

What a useful lot you all are....

[shortliner]

I was going to suggest one of those battery powered smell sprayers that have motion detectors ( from Glade!) - we have three that are about to get the chop as the refills only seem to last about a week - so much for the "up to 30 days" - the batteries seem to last for ever!

[highpeakman]

"So, I have also been looking at GPS, but I don't know how this would feed into software like Railmaster for example".

 

 

 

 

 

 

GPS is often seen as a useful positional input item but there are several things that are often not fully considered. A GPS receiver would require a clear view of the sky so it can see the satellites. Is this for a garden railway perhaps? Also the accuracy for a typical commercial cheaper receiver would be measured in metres not millimetres so how large is your railway is a consideration. The cost to get more accurate receivers would probably be prohibitive.

 

Note that phones with GPS will often just remember where they are when they get inside a building but they need to be outside before that to get their "first fix". There certainly more accurate devices but the cost goes up accordingly and even then they need to see the sky before they start.

 

The software outputs from GPS units normally contains specific navigational positional code formats such as NMEA. I doubt that any model rail software would be adaptable to read it even aside from the positional accuracy issue.

 

The circuits used in phones are not usually available separately but are integrated into the main phone circuits as are the GPS antennas which are needed. It is possible to buy discrete receivers and antennas but they would not be a cheap solution in small quantity.

 

I can understand why you would wish to consider GPS but unless you are working with a large outdoor layout (clear of trees, etc) and don't mind stopping your trains within a few feet each time then I think it is really not a practical and useable device. Sorry.