stopping train at buffer

[ceesquared]

This is for a non dcc layout. I want to have a system for stopping a train/carrages at a buffer. I have tried using a micro switch to cut off power but that can result in a derailment. I have thought of using an IR beam interrupt to cut the power, setting up the tx is not a problem, it is the rx that I begin to run out of ideas on what I need for the circuit board. Has anybody else solved this problem? If so how, what components do you need exactly?

[RDS]

Hi and welcome to the Forum

I would have expected that the microswitch idea would work if the switch was fitted in the buffer as long as the train is only going very slowly when it comes into contact.  If the train hits the buffer hard, that may in itself be enough to cause a derailment.

[Bulleidboy]

I suppose you could have an isolating rail a loco's length from the buffer, with power via an on-off switch. The downside is the loco would stop fairly abruptly - although it would be travelling very slowly. You could also fit hydraulic buffers!

[walkingthedog]

That's what I do BB. 

[atom3624]

OP. Welcome to the Forum, and nice thinking ... but.

 

I would avoid potential damage, as indicated later, and isolate a reasonable distance from the buffer.

With the best of intentions, with all the detailing parts, damage could be incurred if relying on the buffers.

 

Typically there would be 3 tracks between platforms, the middle permitting the loco to uncouple, 'reverse up' to couple at the other end, else continue to the t/table, 180 and reverse back to couple up 'if a Steamie'.

 

Al.

[walkingthedog]

The OP didn't mention a station. Why do you assume 2 platforms? Might just be a siding.

[jane1707819582]

Try using a diffuse scan sensor thee have tx and RX in the same mounting

[LCDR]

What I have done in the past is to have an insulated joint a loco length from the buffer stop, and a push to make switch to power the rail when I have reversed the direction and am ready to depart. Won't always work for multiple units but is OK for loco hauled trains. If you want to slow the train down automatically before you get to the stopping track you can add another insulated section but fed via a resistor to cut power.

[96RAF]

Make a gap in one rail and wire a diode across the gap. This will cut power in one direction but allow it to flow in the other direction. This is how shuttle stops are controlled, except they have a flip-flop circuit to reverse the polarity after a set time.

[atom3624]

WtD where else would you routinely stop a loco and carriages - makes sense - aggressive response again!!

 

It is true, no station was mentioned, I was just throwing a little idea into the mix.

 

For general 'fiddle' work, same approach would be considered I reckon, if space permits of course, and for me at least, definitely don't rely on the buffers to cut power / trigger, to avoid possible damage.

 

Of course, you could have done this in the 60's and 70's when they were made like tanks!!

 

Al.

[walkingthedog]

Carriage sidings I guess.  😉

 

I have passenger coaches and no station. Take up too much room.

[LCDR]

There are methods using a shuttle module which has reed switches in the track and a magnet under the train, works best with Multiple Unit , railcar and push-pull trains. 

 

The only problem with a diode is that if you use another loco to remove the coaches as soon as it pulls them away, the other loco then starts too. However a switch in the circuit prevents this.