automatic passing loop

sparky230

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Any ideas on anyone that makes a module or similar for a automatic passing loop
used them on loops in N OR 00 But all the people i know that make them dont make one that will handle G scale current or voltage.
 
Not too difficult. Just need two reed switches, one in each loop set BEFORE an isolated section in each loop. Reed switch activates point motor. Fix a supplementary switch to point motor and use it to feed track power to each isolated section as point changes. If still interested I can draw it out for you. It's also possible to add light signals for which you also need a relay. Towards end of video below you can see my passing loop in action.
http://youtu.be/f3DGGsf47Mw
 
think i get it, but a drawing would be handy, would guess you only need one powered point as the other could be sprung
 
sparky230 said:
think i get it, but a drawing would be handy, would guess you only need one powered point as the other could be sprung
The first point needs a motor but the second just needs to be free to flop about. No motor or springs.
 
Will do a drawing but probably weekend. Being inundated with visitors.
You can get away with just powering the point at loop entry. However I powered both as I found a bogie on one engine wouldn't shift the point. Trial and error. But as dutchelm says if its loose to flop about then no problem I would imagine.
 
a4d548d765264f0dbad3ce179ee1a158.jpg

Well visitors gone on their way.
Have done a drawing - not great - but hope its sufficient. Hope can distinguish between track and wires.
Notes from experience.
Make sure reed switch is far enough from point to take whole train before point switches.
Make sure isolated length (only need to do one rail) is long enough to take whole engine.
I have used LGB kit because that's what I had but can use anything. Its just the principle of the thing.
You may have to swap the wires round on the switches to synchronise the point with the feed to the isolated section.
I hope this helps
 
Two additional tips in addition to those in the previous post.

Position the isolated lengths of track to ensure that the loco magnet has operated and is well clear of the reed switch before the loco comes to a stop in the appropriate isolated section. If the loco stops with the magnet over or very close to the reed switch the point motor will get power all of the time rather than the short pulse that it needs. The reed switch life may also be shortened by powering the point motor continuously.

Don't use this system for trains that take much more than two amps as this is the continuous DC current rating of the microswiches that LGB fit.
 
Ah, just noticed the diagram shows a three terminal point motor.
For a two terminal motor one way is to use alternate reed switch terminals.
bc92b28ca54c42309f9ccd6d8baceb7e.jpg
 
As most EPL point motors now only have 2 terminals I have scanned off the official LGB drawing. It's taken ages as my antivirus was refusing to allow the PC to talk to the scanner for some reason.
dd231361df15478cbae36daef5d47bf7.jpg
 
Of course point motors have only two terminals. No idea why I put 3. Must have been a brain flashback. Obviously didn't take the pills this am or it could be last night's whisky with boozy friends.
Sorry about creating extra confusion.
 
I can confirm that this circuit works really well. I wired mine exactly as in the diagram, cutting one side of the rail and soldering the correct power lead to the dead section. As the train comes into the station it crosses the reed switch, changes the points and starts the other train. I use this to alternate the trains around my main line.
 
i have some points that have 3 terminals will the aux switches fit these older ones?
 
sparky230 said:
i have some points that have 3 terminals will the aux switches fit these older ones?

Not sureabout the 3 wire types of motor, but if they do, you have to unclip the end of the motor off before you can fit the accessories/aux switch....
 
sparky230 said:
i have some points that have 3 terminals will the aux switches fit these older ones?

Just had a look at my collection of point motors and found an old 3 terminal type. It seems to have a push pull lever on end which operates point so I think the answer is no. AS Gizzy says on the two terminal type the other end will pull out and into space you can push an auxiliary switch.
 
anyone got the internal diagram for a 17100 reed switch, i understand it contains a couple of diodes as well as a reed.
just seems a lot for a reed switch when i've got loads of plain reeds and diodes are 2 a penny in my trade

found it, seems u feed Ac to it and depending on what diode output you use you get a + or _ pulse as the 2 diode are reversed on there polarity
 
There is also a capacitor across the reed switch.
 
sparky230 said:
i have some points that have 3 terminals will the aux switches fit these older ones?

YES.
you just have to wire differently.
the common to the middle and at each side (green and yellow) the orange output from one of the reeds.

-----------

reeds.
for years i make my own copies of the LGB reeds:
reeds.JPG


replacements.JPG
 
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