Electronic points switch for DCC

[ColinB]

I don't know if anyone else has done this, but on my DCC layout I use lots of isolating sections in front of points. The effect of this is if the loco comes the to the point it automatically stops as there is no power. So anyway I needed a switch to enable power to these sections. I tried the Peco ones and found they put a huge load on the point motor and it meant I had to use Peco point motors. Then I tried microswitches, again a pain to set up, then I can across this idea for electrofrog points. What you do is attach one wire to the blade of the point and the other to one of the outside rails. So that when the blade is touching the other rail you get the DCC voltage across the two wires. You now feed this signal into an AC driven relay board and hey presto you have a system that will work reliably with any point motor. If you use a double pole relay you can even switch the frog voltage. Note the wire is attached to the part of the blade that doesn't move.

[Jim-R855]

Unless you have gone the whole hog with modifying your electrofrog points and not only cut the links between the intermediate rail ( the one you are wiring to) and the frog, but added links between the intermediate rails and the same side outer track to remove reliance on the switch rail to power the intermediate rail...

I do try not to end up raving about some non-hornby item in every post I make, but I have to say, I'm really pleased that I chose Cobalt digital IP point motors which have not only the accessory decoder built in, but a switch to take care of frog power which you can hook up to your isolated sections - I have, they work a treat.

I also followed a suggestion to wire a detector (I used magnetic) to switch the points automatically if a train is approaching a point set against it, but soon realised this is very non-prototypical and if you run 2 trains at the same point, the first may still be in the middle of crossing it when the other trips the switch to set its road, derailing the first train before crashing into it. I spotted the possibility before it happened for a change! Much better to have the second train stop so you can check that the route is clear before switcing the point.

[ColinB]

I found with a lot of my electrofrog points that on a few of them the links fell off all on their own, perhaps I have a bad batch. I also found that it is a good idea to do this anyway as quite often as the wheels of the loco move across the point you can get a short. It took me ages to figure how it did it, but it does.

[96RAF]

@jim et al

You can use a second sensor a suitable train’s length past the junction in conjunction with a double pole latching relay that will release the point once the first train is clear. My method would be to have the relay second pole activate an isolated section ahead of the point to stop a second train until the first train had tripped sensor 2 to delatch the relay.

Using software is easier as the train can have magnets on the loco and the last coach and the second sensor can be just past the junction, then when the last coach passes it the previous block is cleared and the point is unlocked.

[Jim-R855]

@ColinB - sorry, just realised my comment looks quite negative, what I was meaning is that your idea looks great for everyone except those of us who have added additional links.

@96RAF - thanks for the suggestion. I'm hoping next winter I'll take my temporary layout apart and design something more permanent with proper routing and stuff and then I'll come back to some of these automation ideas. The current layout is quite good for testing some things, but a bit cramped for others.