Toy train operating and collecting

lionelsoni - "Spot Relay" was Right-Of-Way's term on the packaging schematic.

Here is what is printed on the other side of the relay: (in white lettering)

Potter & Brumfield

KHAU-17A11-12

12V 50/60Hz

1/10HP, 3A, 120VAC

3A, 28VDC, RES.

MADE IN MEXICO

9612

Hope this unlocks some mysteries...

Fife,

         I ran the info, and here is what I found. Hope this helps.

http://relays.tycoelectronics.com/datasheets/KHA_DS.pdf

Yup, that appears to be the critter.  Now I just need to know how to wire the bugger...

Fife,

       You need to use a rectifier between the power supply and the relay

 1. Connect pin 13 to the positive terminal of the rectifier.

2. Connect pin 14 to the insulated rail through the negative terminal of the rectifier. The uninsulated rail must have a common ground with the negative terminal of the power supply.

3. Connect the black wire from the signal to the negative terminal of the power supply.

4. Connect pin 9 to the positive terminal of the power supply.

5. Connect the green wire from the signal to pin 1.

6. Connect the red wire from the signal to pin 5.

probe - what type of rectifier did you have in mind (think small, think Radio Shack)?  Can I use just one, or do I need a rectifier wired to each signal?  Keep in mind, that when I had these same signals hooked up before, I didn't wire in a rectifier...was I just lucky?

Fife,

          I usually go to Radio Shack to get the full wave bridge rectifiers. I use ones that are rated at 4 amps to be safe. You could connect several relays to one rectifier.  If you powered that relay without a rectifier, the relay might be dead now. If it still works, go play the lottery.

Fife,

        I just read the datasheet again, and it says AC voltage can be used to power the coil, so the rectifier isn't absolutely necessary. Sorry about that.

I'm below a novice when it comes to electronics, so no apologies needed.  I appreciate your time and your guidance.  Let's hope this works.

Here's how I would wire it: 

outside rails----transformer common

accessory transformer 12 V or center rail----relay coil 13 (or 14)

relay coil 14 (or 13, respectively)----control rail

accessory transformer 12 V or center rail----relay C terminal 12

relay NO terminal 8----signal red wire

relay NC terminal 4----signal green wire

signal black wire----transformer common or outside rails.

I enlarged the picture of the signal,  There is indeed a yellow light.  Looks like the signal itself may have some hidden features too.

What I had described was assuming an AC relay, and two lights.  After seeing a picture of the other side of the relay, my suggested wiring scheme will not work - I guessed wrong for the common terminal.  Sorry.

lionelsoni - Your last suggestion puts us back at square one.  That is the schematic that the signals came with, and yet, as soon as you connect 13 to the control rail, the signal stays on red, and won't change.  Yes, the rail is insulated on both ends.

We're just missing a step somewhere.

probe - Tried your idea of useing the odd posts (1, 5, 9, 13, 14 to insulated), which netted the same results, just on the other side of the relay.

Back to the drawing board...

Fife,

       I am starting to think that the relay is defective.

If it were just one, I'd agree.  However, I have 4 currently on the layout, and they are all responding the same.

Perhaps use a separate power source than the Z4000...?

It's got to be the control rail.  With no train present, the control rail is just a piece of metal (supposedly) not connected to anything electrically.  Is it perhaps crimped into a metal tie?  If so, is the insulator good?