Train detection

[nicebutdim]

Has anyone tried using LGB's 17100 track contact & 17010 magnet on their layout? I'm looking at wiring an automatic reversing loop controller, I already have the electronics and relays to reverse the polarity, just having a little trouble with detection of the train. I've tried using reed switches and magnets, but (when they work) it produces two signals as the magnet passes over, causing a problem of latching the relay and then unlatching it. If any of you have used LGB's contacts, 1: are they reliable and 2: does it produce a single pulse as the train passes over?
Many thanks, Tim

 

[Philbahn]

Has anyone tried using LGB's 17100 track contact & 17010 magnet on their layout? I'm looking at wiring an automatic reversing loop controller, I already have the electronics and relays to reverse the polarity, just having a little trouble with detection of the train. I've tried using reed switches and magnets, but (when they work) it produces two signals as the magnet passes over, causing a problem of latching the relay and then unlatching it. If any of you have used LGB's contacts, 1: are they reliable and 2: does it produce a single pulse as the train passes over?
Many thanks, Tim

Not done that but have used the reed switches. They are direction sensitive using the diodes.
Yes they should produce single pulses

 

[nicebutdim]

Sounds good, I saw them in Dragon not long ago but now I look at getting some they have vanished, will have to message them and see if any are still in. If anyone is interested in making an automatic reversing unit for reversing loops there is a guy on ebay who sells latching relay boards, they have one input to switch on and off so ideal as it doesn't matter which way the controller is set it will always reverse the polarity and the train can carry on around the loop non-stop. Of course you will need the bridge rectifier or lgb reversing loop track set method.

 

[nicebutdim]

Oh yeah, only for anologue layouts too...

 

[Neil Robinson]

I use one set of relay contacts as holding contacts to avoid problems with multiple triggering. A normally open reed triggers the relay coil to energise and a normally closed reed (or the n/c pair of terminals on a c/o reed) to de-energise the coil.

 

[dutchelm]

I use LGB reeds & magnets to operate my reverse loops. I use an LGB signal with sup switch to reverse the polarity of the main line & it also indicates the direction the power is set. A couple of points I have found out by experience.

The voltage on the reed switch is important. Too low & its eratic, too high & the switch welds closed.

The magnet must be under the first motor of the loco if it has more than !. Otherwise the magnetism of the motor can partially throw the signal.

It is worth wiring a diode controlled section after the reverse loop which will stop the train if for any reason the changeover fails.

 

[nicebutdim]

Thanks for the advice, given me a few points to think about. I've Just had an idea of using a timer delay, set for say 10 secs, to cut off the reed to stop multiple triggers. Here I come Maplin...

 

[korm kormsen]

Tim,

LGB 17100s are reed contacts with diodes.


i use them and some homemade copies as well.

 

[nicebutdim]

I've tried using reed switches but I find as the magnet passes over the switch it produces 2 pulses, prob from the two poles creating 2 fields. The latching relay board I'm using has one input to latch and release the relay, so the 2 pulses are simply turning the relay on and then off again. I'm using this type of board as I'm planning on having two reversing loops at each end of the line, so cannot use a 'memory' type as it could get confudled if the train was stopped and run back round the same loop. This board will simply just reverse the polarity again. Effectively you could have a limitless amount of loops, as it does not require a set and un-set reed. That's in theory anyway, alot of testing to be completed beforehand.