I
Track circuitry.
How finely do you wish to locate your loco?
If it's a case of which section is it in, then there are others ways to do this.
Hello Brian,
Maplin (and others) sell miniature strong magnets, for example 3 mm diameter x 1 mm thick:
http://www.maplin.co.uk/Module.aspx?ModuleNo=26348&OrderCode=KQ21X
(I moved my reply here too.)
One problem with sticking magnets to your locos is if you use magnets to uncouple your rolling stock!
Depending on how much you want to spend...
1) RFID tags (??overkill?) This is a field being developed by MERG
2) you can monitor the current to each track section. The empty sections will have no current flowing.
This can be achieved using a circuit similar to the directional lighting circuit I had published in the NEWS - but in this case the circuit is mounted in the baseboard rather than in the loco. You'd need one for each track section that you wish to be monitored.
Hello Brian,
All the suggestions here are valid, and if you are comfortable with more technical solutions then I'm sure you will be able to weigh up their pros and cons, but do not despair if you are not an electronics wizard.
If magnets and reed switches are 'appropriate technology' for you (and your grandson) and you find they do not cause problems with magnetic decoupling, then I'd give it a try. A couple of reed switches and magnets are not going to break the bank and they can be fixed in place temporarily.
They do have the advantage that you can show your grandson the leaves of the reed switches close (and even hear a faint click) as you pass a magnet over them. He's still a bit young but at primary school they are quite likely to meet circuits at the battery - switch - lamp level (at least they do in Scotland).
You will have to experiment with distances and orientation of magnet and reed switch.
If you are keen on electronic experimentation there are many options, but if you want a solution that is 'off the shelf' then Heathcote Electronics and others sell kits or units that may be suitable.
http://www.heathcote-electronics.co.uk/index.htm (http://www.heathcote-electronics.co.uk/index.htm)
Something like the IRDOT (InfraRed Detection Of Trains) might do it.
The downside is that it can be pricey if you need many units. As a MERG (Model Electronic Railway Group) member myself, the electronics is often the main part of my hobby, but it should not rule your hobby if it is not an interest. It is something that can be very rewarding, but like building brass kits or hand laying track you have to take it one step at a time and start simple.
The advantage of using track circuiting are that it will detect a train (i.e. the motor or anything else that draws current) in a block section whereas a reed switch or something like IRDOT will be momentary. It all depends what you want to achieve.
Thank you gentlemen for your replies.
Perhaps I should give you more information of the layout and why I require some form of train position indication.
I am not using magnetic uncoupling, all the rolling stock is ready to run by Lilliput and Roco purchased 29 years ago for my then four year old daughter, supposedly ;D, and used on a 4ftx2ft Rabbit layout which I demonstrated at the York model railway show, where, much to the annoyance of the profesional exhibitors, who very much looked down there collective noses at this very entertaining, but child oriented toy layout, it was photographed by the local press and printed in the York weekly rag.
It was equally eye opening to me, as this was the first and only exhibition I have ever exhibited at, that despite my crediting Freezer with the design in the bit of blurb I was asked by Mike Cooke to supply, while having to lean over my (his design) layout to photograph Ian Futers boring circular layout for a future article in Railway Modeller, he never acknowledged me in any way whatsoever. So much for modellers cameraderie.
Right back to my problem.
The layout is basicaly the same rabbit layout I built my daughter all those years ago with its severe grades and 6 or 7" radii track popping in and out of several tunnels on three levels. I have slightly modified the layout from it's original form adding a canal with working lock gates, a Dapol windmill which I have motorised, steam whistle sound, and train chuffing noises, when I fit the module.
In other words this is primarilly a toy for a 5 year old, built to entertain and hold his attention with as many gimmicks as I can build into it. To this end, I have built modular track layout indicator board with lots of Green/red LED's which change colour when the track is in use, they are green when that section of track is available, but will turn red as the train passes over them.
The track is not cab control as I found this a waste of time last time I built it, so all the track is live at all times, with certain parts switched off by point motor switches or, track layout switches for station position stops, and at least one dead section on all the off scene points of the layout. This is done because the trains all run in one direction only and it is possible, well it was at York, to have four seperate trains running around the track, and as they pop in and out of the tunnels, keep the children entertained. Because the loco's do not all run at the same speed, they start to catch one another up, by having the switchable dead sections "off scene", I can halt the speeding train and let the other get away.
The Led's will change from green to red as the loco passes over them, so, if a train is halted off scene, the LED for that section will stay red. But' I am having difficulty placing the reed switch magnet under the tiny loco's, hence my original post.
Regards,
Brian.
Ah! Right. A man after my own heart. Not NG, but here is my offering in a similar vein:
http://www.youtube.com/watch?v=qcYlEhymrMQ (http://www.youtube.com/watch?v=qcYlEhymrMQ)
The point solenoids are wired up now and I have a mimic panel (with lots of LEDs) that will go on the layout in the gap on the right. There is also a separate controller fascia to go in there too that will allow shunting in the Inglenook+ with a 4th loco while 3 others chase each others tails.
My attempts at putting resistors across the axles of the rolling stock for track circuiting were only partly successful, so I have plans to add optical 'track circuiting' at the entrance to each of the four main blocks (and possibly even at the end of the sidings to allow semi automatic shunting).
The surfeit of electronics is because there are 5 linked speed controllers (a kind of automatic progressive cab control except the speed and occupancy information is passed from controller to controller and not as might be expected the cabs/controllers being passed from block to block. Five controllers means four trains running simultaneously (there must always be an empty block to run in to).
Enough hijacking your thread!
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Another possiblity for thin magnets might be plastic fridge magnet material:
http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/Fasteners-Fixings/Magnetic-Materials/Flexible-magnetic-sheet/64796/kw/magnetic+sheet (http://www.rapidonline.com/Tools-Fasteners-Production-Equipment/Fasteners-Fixings/Magnetic-Materials/Flexible-magnetic-sheet/64796/kw/magnetic+sheet)
These people have thinner stuff but looks like trade only.
http://www.magnetic-paper.com/trade.asp (http://www.magnetic-paper.com/trade.asp)
If it works, it would have the advantage that you could possibly put a reasonable length along the length of the loco and even under rolling stock.
As for adhesive, non-solvent UHU might do it, though the plastic magnetic material may be self adhesive. The UHU sticks fairly well (the track and point motors in the video clip are glued to the foam rubber base with it) but you can prise off the object and srcape off the residue. Solvent-based UHU eat my Peco track.
Thank you Graeme, the fridge magnet material might be an idea worth investigating if the material is powerful enough??
I have seen advertised on Ebay some small round magnets made of "imodium" whatever that is. They look quite tiny but they are not cheap.
Regards,
Brian.
Quote from: gtmspyder on October 29, 2010, 12:44
Thank you Graeme, the fridge magnet material might be an idea worth investigating if the material is powerful enough??
I have seen advertised on Ebay some small round magnets made of "imodium" whatever that is (anti diarrhoea medicine) . They look quite tiny but they are not cheap.
Regards,
Brian.
;D Neodynium or something like that.. NdFeB magnets
from 20p to 40p each
http://www.hasslefreeminiatures.co.uk/range.php?range_id=58&subcat_id=58
available at the wargames show at Leeds Royal Armouries museum on Sunday
Thank you Stephen, unable to visit Leeds this weekend as I am going away for a week darn sarf. :D
Regards,
Brian.
Well they do mail order too.....
or if you want in bulk
http://shop.ebay.co.uk/?_from=R40&_trksid=p3984.m570.l1313&_nkw=rare+earth+magnets&_sacat=See-All-Categories
Hello again Stephen and Graeme.
I purchased some of the 4mm diam. by 1mm thick magnets from Ebay and put one under one of the Liliput loco's, I stuck it to the coupler retaining setscrew, placed a reedswitch in the track temporarily wired up and lo and behold, I got two beeps for the prace of one as the loco passed over it.
These magnets are incredibly strong compared to the bulky bar magnet I had first used.
So, problem solved, thank you all for your assistance.
happy modelling, regards,
Brian.
That's good news! The eBay sources that Stephen pointed out are certainly cheaper than the shops I knew about. I must remember it.