Operating switch tower...direct power/multiple tracks?

The latter half is simple, a second trigger rail (or equivalent). One on each track. Each capable of introducing the missing common side/rail which completes the tower circuit sending it into action. Neither will effect the other outside of holding a "run" condition until both legs are removed.

The first question needs more input facts and means we have to look up the original operation & schematic/diagram ourselves too

Maybe later

List your thoughts on the intended power supply(s) and trigger you intend to use.

Tell us whàt you meañ by "limit ño matter what" means. 

Limit maximum voltage? (say command 18v on track and/or acc. but you never want more than say 14v to get to them? or you want a 14v limit because kids might throw the transformer to 100% at 18-20v...?)

Context means a lot.

Definitely do-able, but as Adriatic suggests, the devil may be in the details here.

Switchtowers and Gateman are very similar.  Both use a solenoid (or similar motor mechanism for some modern units) for the motion, and also have a light inside.

Lots of times, one side of the solenoid and one side of the light share a hookup terminal (though this may vary depending on which model you have - modern versions may have differently marked terminals than post war versions).

The general idea is the same though.  You apply the "hot" voltage (whatever your source is, small transformer, additional constant voltage tap off of the one you are using (like if you have a TW with available unused taps), etc) to the post that is shared.  This provides the  voltage you desire so it's independent of the track voltage.  Your "triggers" as Adriatic outlined are then hooked to the other terminal of the solenoid and/or light, providing the common/ground to the circuits so the action and light come on when the train passes by your trigger points.

-Dave

What transformer do you intend to use?

Do you want the light on all the time?

Do you intend to trigger it with contactors or with insulated rails?

From memory, terminal #1 is the common connection, #2 is the lamp, and #3 is the solenoid (electro-magnet that makes the dispatchers move.)

Here's one (of several) solutions:

Assuming you want to use insulated rails, put steady hot (14 Volts) on #1, ground (same as track return) on #2. That will give you a steady lamp in the tower.

Run a wire from any (both) insulated rails to terminal #3.  The solenoid has hot on one side, waiting for a ground to complete the circuit. When a train passes over an insulated rail, the solenoid will operate.

When using multiple accessories off of isolated rail triggers, it's a better idea to use the trigger to activate a relay(s) .  

The low amp draw of a well chosen relay coil will activate easier and with less long term pitting damage to wheels or track from higher current sparks that might occur. The relay points handle the actual higher current; constant voltage switching to the grouped accessories. 

Another note on info. You haven't actually told us if this is postwar or a more recent version of towers or gates. Control isn't always the same from new to old. E.g. the amp draw on the new is almost definitely much lower than PW versions of either gate(s?) or tower and use of a relay possibly less critical.

Thanks for the replies so far!  I'm using the MPC 6-2324 tower, so it's still "old school."  I'm using a ZW on one line, a KW on the other (still old school.)  I've got the tower lights rigged to a separate transformer, so I can turn it on/off with my other lights.  I'm using an insulated track section on the line farthest from the tower, but with modern locomotives, I've really got to crank the power to get the solenoid to trigger, thus my dilemma.  I'm also concerned about running the power to the tower off two different lines...will that cause a problem, especially when two trains are triggering the tower at the same time?  Thanks again, and hope this gives more info!

@Arthur P. Bloom posted:

...........

From memory, terminal #1 is the common connection, #2 is the lamp, and #3 is the solenoid (electro-magnet that makes the dispatchers move.)........

 

Looking at both a PW Repair and Operating Manual sheet, and also a 6-2324 instruction sheet (from the Lionel site), I think 2 and 3 are probably backwards.  It looks like 3 is lamp and 2 is solenoid.

@Tony BNSF posted:

Thanks for the replies so far!  I'm using the MPC 6-2324 tower, so it's still "old school."  I'm using a ZW on one line, a KW on the other (still old school.)  I've got the tower lights rigged to a separate transformer, so I can turn it on/off with my other lights.  I'm using an insulated track section on the line farthest from the tower, but with modern locomotives, I've really got to crank the power to get the solenoid to trigger, thus my dilemma.  I'm also concerned about running the power to the tower off two different lines...will that cause a problem, especially when two trains are triggering the tower at the same time?  Thanks again, and hope this gives more info!

We need info on your 3rd transformer.  It's important for some of the below discussion.  For the ZW and KW, "U" is common, but for many single throttle transformers, it can be a different arrangement. (not to say other units can't be used compatibly, but it's a detail that needs to be understood)

Also, while some of our discussion points above sort of imply it, are you absolutely sure you are set up with common ground wiring?  Meaning are the U terminals for the KW and ZW connected together, and the transformers phased properly (assuming non-polarized plugs that you can reverse at the outlet if needed) when plugged into the wall outlet?  Search "phasing transformers" on the Forum if none of this rings a bell or your answer is not an immediate "yes" to the question of whether your transformers are phased.

Once we confirm you are using common ground wiring, the issue you express concern of running power "off two different lines" is I believe eliminated.  The closure of the solenoid circuit via insulated rail is the same for either line, assuming you have the common ground wiring and both transformers "U" posts are at the same potential no matter the voltage settings on any of the control handles.

Also a quick sketch of what you already have might be helpful. (which transformer terminals are hooked which rails of track, as well as what each terminal under the 2324 is hooked to, including which terminal of the 2324 is hooked to your existing insulated rail)

The part about needing to crank the power with the modern locomotives is driving me asking all of these additional questions.  (I'm assuming you mean you have to turn it up enough that the engines go faster than you would like them to)  The voltage on the center rail should not impact the function of the insulated rail, which is only supposed to be providing the outer rail connection as a ground point for the solenoid.

{edit: after reading Adriatic's response below, and re-reading this post, I realized I goofed.  I know you said you had an insulated rail already hooked up, but you do not yet have constant voltage for the solenoid (the whole point of your post! ).  I goofed and applied a train of thought that assumed you had already set up the constant voltage, which is not the case.  So I was wrong to suggest puzzlement at the too fast train when you get the tower to work properly.  That does make perfect sense for the setup you currently have.}

-Dave

I too think the bit about throttling up it is to get action from the acc. and the locos are to fast while doing it; so he is going to power the action separately from both lights and track.

As mentioned, all units must be phased so you can combine commons.(I like the Lionel video on YouTube "Phasing two or more tranformers for use together")

This last transformer choice might be relevant. (so far, sound great)

The two Iso rail triggers would just deliver the missing common to the tower.

Using two or ten triggers at once poses no curcuit danger here (outside of  heat if it never-ever sees off time and is set to very high volts.)

You can feed the action's hot wire source from any of the taps that use these same commons; but don't mess with odd voltage combos unless they feed a totally isolated circuit.(also worth noting some of those acc tap combos are not breaker protected internally and should be fused/breakered.)

(a relay is also a simple way to totally isolate the action fed circuit from the trigger circuitry on the rails. With a relay you could use a button cell battery to turn on a 440v three phase welder.)

You mention it is "far away". Is the wire used big enough to handle the draw of the accessory? Wire choice is about X-amps drawn over X-distance. Too light a wire for too long a distance won't improve much with more power simply being available; it also needs to be able to reach the item and still have strength there. 

E.g.if. you simply matched it for twenty feet it might underperform where if you used a larger gauge it might work fine, with more of a snap and needing less voltage at the dial. (because distance on light wire = voltage drop too)

I made a brief edit to my earlier post.  I goofed in my earlier train of thought in one aspect.

It happens from time to time...

-Dave

This is rough, and could vary somewhat, but may help see how two iso rails or twenty doesn't matter. (each square is a power supply, could be constant, could be varible.)

It also shows the lamp with a common to the rail when it could go to the trañsformer common too. 

The #1 #2 #3 leads can't even be seen in the service diagram, but the light either needs it's own wiring because of using the iso rail triggers OR needs the relay for the tower action to be switched on/off on the hot leg.

Also note the grey commons to the track need to be a larger gauge than reds, because the greys, from transformer to transformer then to the track, each section between transformers, carries the amps of the transformers before it, so at each "stop" the bus should get larger. Between the last and the track drops it should handle ALL amps combined.

The reds only carry amps for one suppy.

  (don't short yourself on the common side bus gauging; I see this a lot)

Nice diagram!  Hopefully that helps illustrate the points.

There is a minor issue with regard to the 2324 tower, however.  Without doing some modifications to the tower, there is no way to hook it up as shown.

The tower has only 3 connections, as previously discussed.  The one that is common to the lamp and the solenoid is a physical connection, it's not just a wire you could snip to separate the two (even if you wanted to).  The metal plate that the solenoid and other mechanical elements (pivot for the arm with the men on it, spring, etc) are mounted to is the shared connection (via the metal post that runs down to  the Fahnestock clip #1 on the base).  One side of the solenoid coil is connected to this, and the metal holder for the bulb (physically mounted to this with no insulation) uses this same point as the "sleeve" connection for the bulb.  The "tip" of the bulb is on clip #3 and the other connection for the solenoid coil is on clip #2 on the base.

Of course, if one wanted to replace the bulb with a new one and just run 2 wires out of the bottom of the accessory, that would be a work-around here.  I'm assuming we don't want to do any modifications to the tower though.

So this is where the use of the insulated rail makes it more complicated, if you want to have a different voltage for the light (as described, on a separate transformer, and always on) and the coil(obviously not always on).  (Though using the relays can eliminate the problem I am about to describe.  This problem is only if you are strictly using the insulated rail as the direct "ground" trigger for the solenoid)

We can't simultaneously have a circuit that will use an insulated rail to trigger the solenoid and also have a different voltage source for the bulb (if the bulb is to stay on all the time). 

You could have a different voltage source for the bulb and solenoid, but only if the bulb is only going to light when the train goes by to trigger the insulated rail.  This would be accomplished by applying the 2 "hot" voltage posts from the transformer(s) to clips 2 and 3, and having clip 1 route to the insulated rail(s).  This eliminates the possibility of the light being on all the time though.  It will only light when the train passes.

Alternatively, you can hook a single "hot" to clip 1.  that allows you to hook clip 3 for the bulb to a common (ground) terminal on the transformer, and the bulb is lit constantly.  Clip 2 for the solenoid is hooked to the insulated rail and only causes motion when the train goes by, independent of the bulb.  Both the bulb and solenoid must operate at the same voltage though.

I am starting to think the way it is hooked up now is with something other than common ground for the transformers powering the solenoid and the light.  This is a preliminary thought (haven't drawn it out in detail to confirm my suspicion to myself ), but if it's not common ground, the source for the light might be causing the voltage for the train/solenoid to need to be too high, because the other side of the circuit might not really be at the same "ground" as the track is.  In that case you are trying to energize the solenoid with the difference between the bulb voltage and the track voltage, hence the need to set the track voltage higher than should be needed to trigger the solenoid. I'd remove the wires to the transformer currently powering the bulb, and then check the train speed vs solenoid operation again.  If I'm right, the train should be able to run more slowly while still activating the solenoid.

-Dave

Curious if you ever resolved this, Tony?

Did you end up re-wiring anything, or figuring out why you had to turn the power up so much to get the solenoid to trigger?  Or get really thorough and add relays as Adriatic discussed?

-Dave

Hey Dave- Haven't had a chance to work on it, but the plan right now is to use a combo of the two ideas.  Since there are only three connections on my tower, I'm planning on starting by just running a separate wire for lighting, and going from there.  Thanks!

OK; finally getting a chance to work on this.  Starting out by running a separate bulb to a different circuit, to simply things.   

Success using a combo of both suggestions!  Tower working a zillion times better with its own power- now net project day I'll connect it to a second track.  Thanks again, Dave and Adriatic!