electrical hook-up for banjo signal

If your on track power or accessory power and it's always on, you have a wiring problem with the isolated rail, or wiring. Shouldn't you be hooked to D and U? Not familiar with the KW.

The KW has 6V,14Vand a 20V constant.  6V hook up is U post plus 1 D post.  To get 20V you use the other U post and the other D post. To get 14V you use both D posts.  Unless someone tells me different.

So, are you saying it CAN be done? Somehow separating the 14V constant to the accessory AND allowing the train to cross the track at any/variable speed?

@Mike23 posted:

...

I am using a KW transformar which would mean- to get 14V I need to attach a wire to BOTH (D) posts.    I'm only guessing at answers so- I don't know anything-  Is there a hook-up for say- Any- two wired accessory- that won't be constantly on?  Or just say no and use track power only.

I have not used a KW but in looking at the instruction manual diagram, I'm not sure what you mean by using BOTH "D" posts to get 14V.  It seems to me you get 14V by using C-D.

In any case, if I understand what you're trying to do, you want to use the KW's fixed 14V to drive the banjo AND trigger the banjo using the isolated-rail method.  The "problem" is the isolated-rail method requires one side of the 14V to be the same the the outer rail (U post).  The diagram clearly suggests this is NOT the case; that is, the C and D posts are NOT the same as the U post.

This may be wasteful of your 2nd throttle, but you could dedicate the variable U-B throttle voltage to be your Banjo voltage.  In other words, the U-A throttle is the variable 6-20V control for your trains.  But the U-B throttle is set/dedicated to 14V for your banjo (and any other 14V accessories).  The 2-wire banjo signal is powered by the B post and the insulated-rail section (equivalent to the U post).

Thanks. I should have said C-D.

So, even though the train might be moving through at say 18V, If I'm somehow hooking the banjo to a different throttle it will get 14V via the train making a connection that puts the banjo into motion?

Right.  So thru the miracle of cut-and-paste, assume the trigger "zone" is as depicted above in the orange box and "created" using insulated fibre pins or the equivalent to isolate a section of outer rail.

When any metal train wheel/axle straddles the outer rails, this electrically applies the U post to the insulated rail trigger section.  This then applies U-B (which was set to fixed 14V) to the banjo.  And it doesn't matter what the train throttle (U-A) was at the time...it could be 6V up to 20V.  The banjo will only receive the fixed 14V.

Thank you for the help. I "see" what you're saying although I don't understand electricity, so thanks. If I could ask a couple of random questions-

I have a 3 wire news stand and a 3 wire watch tower, both work fine. They engage with the train crosses isolated track. They run on 14V buuut - not the banjo? Is it actually hooked up different because 2 wires VS 3 wired accessory?

Does it matter which rail you isolate? I mean both are ground so why the outside one. Just to be uniform?

Second throttle is being used- I might just get a small transformer and hook all my banjo/crossing gates to that.......With 2 trains on 2 sepárate track- can I hook up ALL accessories that are on BOTH track to that one transformer? Or a separate power source for each.

Thanks so much! Here's a video for your help!!

Your 3 wire accessories have 2 of their 3 connected to the transformer.  Connect these 2 transformer wires to the 2 banjo wires and the accessory should operate.  Does it operate as expected ?

Regarding your "why is it the outside rail" question.  Normally both outside rails are connected the the transformer neutral (your ground terminology).   Insulating one outside rail turns this track section into an electrical switch which "closes" when the train crosses the insulated section.  The train wheels/axels provide the electrical path which in essence "closes" the switch.

When you hookup your banjo make sure one wire is connected to the insulated rail and the other is connected to the non-neutral transformer wire.

@Mike23 posted:

I am using a KW transformar which would mean- to get 14V I need to attach a wire to BOTH (D) posts.

There is no track-common 14 volt accessory tap on the KW, only 6 volts and 20 volts.

Perhaps this diagram will shed some light.  You should be able to click on the image to get more resolution.

If I understand your situation, your two KW variable  throttles control the trains on two loops which I call Loop 1 (U-A) and Loop 2 (U-B).  As discussed previously, you cannot use the KW's 14V fixed Accessory voltage for insulated-rail triggering since the 14V is between C and D...as opposed to between U and C, or between U and D.

As you correctly suggest, you can use a separate train transformer that puts out a fixed 14V AC Accessory voltage.  By "separate" this means it has its own power cord that plugs into a wall outlet.

You then connect the new 14V common (often the "black" post) to the U post of the KW.  In effect, this makes the black post equivalent to the KW's U post.  Now you have fixed 14V between the new Accessory transformer's "hot" (often the "red" post) and the KW's U post.

So to answer your random questions:

Yes.  The single Accessory transformer can power 2-wire and/or 3-wire accessories that are on either loop.  Of course this assumes the Accessory transformer has enough power (Watts) to drive all your accessories.

Yes. It doesn't matter if the insulated-rail trigger section is on the inside or outside outer rail.  I don't show full loops but this is shown on the right loop where there's one trigger section on the "top" side and another trigger section on the "bottom" side.  This also means you can have multiple trigger sections around a loop.  I show what I call "straps" or "jumpers" between the outer-rails of the regular track sections.  By regular I mean NOT the insulated-rail trigger sections.  Some track systems have these electrical connections built-in to regular sections of track; other track systems you must make these connections yourself.

And, if not obvious, you can have multiple accessories triggered by one insulated-rail section.  This is shown on the left loop where you have one 2-wire accessory and one 3-wire accessory triggered by a single insulated-rail section.

Here's a wiring diagram for insulated rail use for the #140 from a 1960 Lionel Service Manual:

I suspect the lower right picture on page 18 is what you want to do......

Peter

You guys have been a great help and I know I'll be coming back to this discussion to remember what you said.

I do have a crossing gate, a gateman, the banjo a news stand and even a watch tower. All run fine even if I can't remember each time I hook one up!

The one thing I do/did different is == in the photos, the "ground" is on a clip outside the insulated rail......I have mine hooked up to the non-insulated rail oposite the newly made insulated rail. Seems like it's doing the same thing.   So, on mine- I have a wire on each inside/outside rail of the isolated track.

In summary, there are several approaches mentioned above all of which will work:

1)  Add a second transformer to provide 14 VAC accessory power.  The best and a long term solution.  I used a 1033 with my KW.

2) Run the Banjo off track power, the A-U or A-B solution. Lionel says the Banjo works on 12-18 volts.  Banjo performance will vary depending on the voltage. I would recommend testing your Banjo first by varying track voltage to determine the range of track voltage that yields acceptable performance.

3) Run the Banjo off the same transformer power as the other 3 wire accessories.  Just guessing, but this probably is D-U.  Maybe the Banjo operation will be acceptable to Mike23.  I would expect the Banjo will run too fast but maybe not ?  If to fast, the question is how to simply cut the voltage down. (serial diodes, resistor or lamps)

There are still other more complex solutions which use KW C-D 14 volt power, like a relay or a track side IR sensor.

KW C-D power cannot be used directly with an insulated track trigger for reasons mentioned in this thread.

Mike23  - on your already working Newstand, I presume the Newstand light is on constantly and the Newstand operates when the train passes ?   What terminal is the Red wire connected on the KW ?

In your diagram, the outside rail is insulated by the "pins".   The inside rail is connected to which terminal on your KW ?  I'm asking which terminal on your KW is providing track power to the inside rail.  Your Newstand diagram looks in error.  Either your Black and White wire labels are incorrect or the wires are actually reversed.    As shown, the Newstand would operate all the time and the light would come on when the train passes?

the colors of the diagram do not match the colors of the news stand.

On my news stand hook up/ the red wire of the news stand go to a transformer constant.

the white wire got to the newly made insulated rail.

the black wire goes to the opposite rail which is just a normal rail. pictures below.  I also use a button to operate the news stand manually.   Yes, the light stays on all the time.

the "red wire in the photo is an extension of the white wire so it is white

My intent is not to sort out wire color but to determine which terminals on your KW are providing power to your Newstand.  Hence, based on you diagram what terminal on your KW is the wire going from the Newstand to your KW connected ?

Also, what KW terminal is the outside rail connected too.   Is it U or something else ?

My thought is: Why can't you maybe use the same KW terminals that feed your Newstand for your Banjo ?

the red wire from the news stand goes to one post of the 14V constant on the KW. no other wires go to the kw.

if one wire from the banjo went to the constant and the other went...where ever, the banjo will be on constantly. If the second wire is connected to...wherever, the banjo will come on at track power

OK,  the red wire goes to one post of the 14 V constant.  Is it terminal C or D ?

There is a wire that goes to the inside rail from your KW.  It provides power to the track.  What KW post is that,  maybe U.

So referring to your Banjo diagram.  The wire running from the KW to terminal 1 on your diagram.  Connect this wire to the same 14 V constant Red wire mentioned above.  Referring again to your Banjo diagram, connect the Terminal 2 Banjo wire to the outside insulated track.  Assuming that your inside track is connected to KW terminal U.  The Banjo should operate when the train passes.  The question is are you happy with how it operates ?

So back to your original post, is the objective to lower the 20V to 14V because the banjo is "hyper-active" at 20V?  I assume this is a vibrating-type mechanism(?)

There have been reports of some success by simply installing a 10-cent diode in the red wire from the D post to the banjo.  This cuts the power applied to the banjo in half...but still applies the pulsing voltage that vibrates the electro-mechanism and hence swings the arm. 

Late to the game I know.  I wrestled with this years ago when I had a banjo signal.  I ended up going the B-U route when A-U was being used to power the track.   There were other ideas that I considered but did not get around to trying:  1) Use a relay off the track in conjunction with the C-D terminals; 2) Tapping into the track bus line (since I was operating conventional, typically in the 10-14 volt range) and 3) wiring the banjo in series with one on the other side of the track.  Anyone try any of these?

ok, I'll give that a try.

This picture is the hook up of my news stand that I have no problem with. light is on, everything moves at 14V when train passes over

I'm not suggesting you run the Banjo on track power.  I suspect your Newstand runs on D-U, the KW 20 volts.  Hook the Banjo up using D-U.  In your latest diagram hook one Banjo wire to D, the red wire i think.   The other Banjo wire hooks to the insulated rail.    Your Banjo will work providing your inside rail is hooked to U.  Stan's latest diagram illustrates this.  With this hookup your Banjo will run faster.  You're almost there and this is not above you paygrade.  You can do this.

Some things to consider.  When you use isolated rails you want to be consistent in using either the inside or outside rail, not both.  The idea is to use either the outside or inside with no isolated rails, so one rail (inside or outside) provides a continuous circuit around the track.  Otherwise you can get dead spots in your layout.  Also in your latest diagram, it looks like the "U" Lock-on is on the same rail side as the insulated rail.  You need to reverse it, so "U" is not on same rail side as the isolated rail.

Lionel says the Banjo can run on 12-18 volts.  Given that it appears your other accessories are working successfully on D-U, 20 volt connection, I suspect the D-U is actually somewhat less than 20 volts.  So you should be OK from an overvoltage situation.  You could just touch the two Banjo wires momentarily to D-U as a test to see how it operates.

@shorling posted:

When you use isolated rails you want to be consistent in using either the inside or outside rail, not both.

This doesn't really matter with tubular track & Super O.  It matters a little with GarGraves, but not much.

@shorling posted:

...I suspect your Newstand runs on D-U, the KW 20 volts.  Hook the Banjo up using D-U.

This will overheat the coil and burn out the bulb pretty quickly in addition to running ridiculously fast.

There is no easy way to run the banjo with fixed accessory voltage on the KW.  The easiest way is to phase a small $5 25-30 watt starter set transformer with the KW and power the banjo with that... this will allow easy fine-tuning of the accessory to account for line voltage, wear, heat.

You can't get 14 volts from ONE post.    The 14 volts is between two posts C-D.  You have your Newstands connected to the D post.  The other Newstand wires go to the U post.  One wire (light) goes through the Lockon rail (U) and the other (Newstand operation) goes through the insulated rail which connects to the other rail (U) when the train passes.

You can't wire the Banjo to an insulated rail using the 14 volts from C-D.

That's exactly right.  There is a wire coming from the U post to one of your outside rails.  This wire is attached to a lock-on somewhere on your layout.

So attach one Banjo wire to post D and the other Banjo wire to the insulated rail.  The Banjo should work when the train passes.

@shorling posted:

...The Banjo should work when the train passes.

At 20 volts.

Shorling.
you can hook up 6v or 20 v using the U post and constant yes.

you cannot use a U post and the 14V constant. In the KW  

The 14 volt option already mentioned is add a 14 volt transformer,

@Mike23 posted:

Shorling.
you can hook up 6v or 20 v using the U post and constant yes.

you cannot use a U post and the 14V constant. In the KW  

All true statements.