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Double Slip Swith Dilemma revisited

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Posted by lionelsoni on Saturday, June 30, 2007 9:05 AM

Here is the power-supply circuit for the slipswitch:

(ground)---(supply)---(diode|)---(resistor)--V--(+capacitor-)---(ground)

(ground) is the transformer common, the layout's outside rails generally.

(supply) is an AC voltage from your transformer, either an accessory voltage or a variable voltage.  Or it could be a completely separate transformer whose common is also connected to ground.  It could also be the same voltage that you have connected to the center rail of the track.  The voltage depends on what the slipswitch needs; but I would start with 10 to 15 volts.

(diode|) is a rectifier diode.  The | is the stripe that indicates the cathode terminal.  You could use a 1N4001 (Radio Shack 276-1101) or anything larger.

(resistor) is a power resistor.  It charges the capacitor slowly over several seconds when the train is not on a control rail.  Use 100 ohms, 10 watts (271-135 ).  You can also use an incandescent lamp, like a number 53 (272-1117), in place of the resistor, for a faster, more complete recharge.

(+capacitor-) is an electrolytic capacitor.  It stores up and discharges the current that throws the slipswitch.  Usually the negative terminal is the one that is marked.  Like the voltage, its size depends on the slipswitch; but I would start with 4700 microfarads at 35 volts (272-1022).

V is the voltage that connects to the common terminals of both switch machines.

The L terminals of both switch machines are connected together and connected to two insulated control rails, one on each end of the slipswitch, both in one of the two paths through the slipswitch.

The R terminals of both switch machines are connected together and connected to two other insulated control rails, one on each end of the slipswitch, both in the other of the two paths through the slipswitch.

Bob Nelson

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Posted by Fred Bear on Saturday, June 30, 2007 2:02 AM
Yes sir, that is corrrect. Jake
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Posted by lionelsoni on Friday, June 29, 2007 11:21 PM
Jake, is it true, as I inferred, that you want to use the slipswitch as a substitute for a crossing, so that only the two straight paths of the four possible paths through it are needed?

Bob Nelson

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Posted by Fred Bear on Friday, June 29, 2007 9:57 PM

Please keep in mind I'm trying to make the incoming train throw the switch. 

Both switch machines in the double slip work together, but I still am not clear at all on how to make the incoming train throw the switch so the next train will do likewise and not end up on the same loop. Is that possible and if so, can someone describe the wiring for that in pretty basic terms? Thanks to all that are trying here, much appreciation. Jake

PS. the middle post on the switch machines goes to U post on the transformer, the two outsides will throw the switch if hit with a hot lead.

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Posted by lionelsoni on Friday, June 29, 2007 9:44 PM
Dale and I obviously disagree on whether a relay is needed.  I have over two dozen turnouts powered by capacitors and thrown with control rails, but no relays.

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Posted by Anonymous on Friday, June 29, 2007 9:34 PM
I never saw a slip switch but from Chucks diagram it looks like it would contain 2 switch machines. I have Atlas switches for sidings and I wire them in parallel and throw them in pairs with capacitors. Each switch machine has 3 terminals lets call them 1,2, and 3 The middle one, 2 is common. If you take a transformer set at 16 volts and connect the center terminal, 2 to one tap, touching other tap to either outside terminal ,1 or 3 should throw the switch one way or the other. Now if you run wires to the second machine, 1 to 1, 2 to 2,and 3 to 3 the machines will then throw together when power is applied. If this is not the desired route simply reverse wires one and 3 on either machine.

In my previous post I described how to automate the switches using a insulated rail,relay and capacitor. The coils cannot be powered more than a brief moment or they will burn out. Throwing the machine coils with a charged capacitor eliminates this problem. Atlas coils can also be thrown manually with a capacitor using a DPDT toggle switch instead of a relay. The wiring is the same as for the relay contacts. The relay allows for automation using an insulated outside rail.

Dale Hz
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Posted by chuck on Friday, June 29, 2007 8:24 PM

I don't know if this is any help, but this is the wiring diagram for the Ross version of the double slip:

 

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Posted by Fred Bear on Friday, June 29, 2007 8:19 PM
Dale, can you do a simple mans description for exactly how I can wired these switches? Thanks Dale, Jake
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Posted by Anonymous on Friday, June 29, 2007 8:05 PM
As I mentioned in the other post you can throw the switches with a relay and capacitor. You can also throw 2 machines wired in parallel in tandem. Just use a 4700uf capacitor instead of a 2200 uf one. That is enough to throw 2 machines. Everything else I describe would stay the same.

Dale Hz
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Posted by Fred Bear on Friday, June 29, 2007 7:54 PM

OK, all Atlas switches are wired the same. The schematics for any switch is identical, so whatever their machines are , they install them in all switches.

Attach the U Post from the transformer to the middle post on the switch, then touch the power wire from the transformer to the left post, the switch throws. Touch the power wire to the right post, the switch throws, each time power is added to one post, it throws, unless of course you touch it to the same post twice in a row. Does this anwer the question? Does this arrangement allow some configuration for automatic throw? I cannot imagine this cannot be done somehow, using a motion sensor, relay, or something. I have a circuitron circuit board that uses photo cells imbedded in the track for sensing an oncoming train, but that would burn out the switch I think, unless the switch once throw cuts out it's own contact with power? Jake

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Posted by lionelsoni on Friday, June 29, 2007 7:05 PM

Jake, we know so far that the slipswitch has two coils.  Can you tell us what the paths through it are after energizing each of the coils individually?  You should be able to do this just by connecting a transformer briefly to the center wire and one of the other wires.  Then repeat for the center wire and the other wire.

Later:  After some searching, I was able to find a large enough picture of this thing (ATO6027) to get an idea of what we're dealing with.  It appears that it has two switch machines, each presumably with two coils, for a total of four.  Imagine the slipswitch arranged left-to-right in front of you.  When the points on the left side are up and those on the right are down, there is a path from the upper left to the lower right.  When the points on the left are down and on the right, up, there is a path from the lower left to the upper right.  When both sets of points are up, there is a path from lower left to lower right.  And when both sets of points are down, there is a path from upper left to upper right.

I think Jake wants to use the slipswitch as a substitute for a crossing.  If so, only the first two arrangements are needed.  So it is possible to connect the coils together in parallel.  The commons (apparently the center terminals on each machine) go together.  The inner terminals go together; and the outer terminals go together.  Then applying a voltage between center and outer terminals should line it for one path; and a voltage between center and inner terminals for the other path.

So, everything I have said about what I thought was a two-coil device applies to the four-coil device with the switch machines wired together as I described.  If trains can approach from either direction on either track, you will need four control rails.  But the two rails on each track can be wired together, so that the same configuration results no matter which way the train comes from.

Am I on the right track (so to speak), Jake?

Bob Nelson

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Posted by Fred Bear on Friday, June 29, 2007 5:50 PM
Each time it approaches the switch, by use of an insulated track piece or some other means, it will trip the switch automatically. This way, if the second train comes, it will automatically go to the other loop. Any ideas on this deal? Jake
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Posted by chuck on Friday, June 29, 2007 5:44 PM
A double slip switch is a little unusual.   The slip portion either allows the loco to pass as a crossing, or divert to the opposite leg.  There is no "wrong way".  I'm not sure what you mean by having the approaching loco automatically throwing the switch?
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Double Slip Swith Dilemma revisited
Posted by Fred Bear on Friday, June 29, 2007 12:28 PM

I talked to Atlas tech support yesterday, explained to them that I wanted a train entering the double slip switch to throw it automatically before entering the switch, they told me with what is available out there now, it's not possible.  Did maybe I not explain what I was trying to do on here? Seems like Bob Nelson had it pinned down. I don't want the train to slow down or stop, just throw the switch. I was told that because of constant track voltage, nothing would work, unless maybe I did not explain myself clearly to them! How I wish now I would have used a crossover at 22 degrees! Jake

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