Wiring a Tortoise + R/G Bipolar LED + Tomar Dwarf Signal

Model Railroader Electronics and DCC
1

I want to hook up a Tortoise switch machine, a R/G bipolar LED, a Tomar R/G dwarf signal and a DPDT mini toggle switch using a 12 V power pack.

I’ve looked at all the wiring diagrams I could find and I can’t figure them out.

What I need is someone to tell me to hook this wire to that wire.

This is what I’ve been able to do so far:

The mini toggle switch has 6 contacts, from top to bottom, let’s call them 1&2, 3&4, 5&6. I hooked 1 to 6 and 2 to 5. The two leads from the power pack go to 3 and 4; 5 goes to Tortoise pin 1; 6 goes to Tortoise pin 8 .

1 goes to a resistor to one leg of the bipolar LED and 2 goes to the other leg. So far so good. The Tortoise works and the LED switches between Red and Green.The mini switch and the bipolar LED will be fastened to the front panel on the layout.

The Tomar Red and Green dwarf signals has 3 leads (Red, Green and White) and I can’t figure out where to go from there. I would like the Tomar signal to match the bipolar LED.

I’ve played around with the other Tortoise pins, 2,3&4 and 5,6&7 but don’t know how to make them work. Their instruction sheet don’t help me at all.

There are lots of decoder step by step installation photos available. I wish I could find something similar for this situation.

So to repeat, can someone tell me to hook this wire to that wire, then that wire to this wire, etc., etc.

Thanks for your help.

2

Well, from that description it should not work. There has to be more. I would think there also has to be a wire from pin 1 of the mini-toggle to pin 6 of the mini-toggle, and also from pin 2 to 5.

I cannot find the instruction sheet for the Tomar dwarf on-line anywhere but my guess is that you would wire it the same as the bi-polar LED. Put another resistor on the white wire. Connect the red and green together. Connect the other side of the resistor to #1 and the combined red/green to #2. If the colors are opposite of what is desired just switch the resistor to #2 and red/green set to #1.

There are at least three more ways I can think of off the top of my head to connect this dwarf, but if you don’t understand electrical schematic diagrams, I think any of the other methods will be too hard to describe.

3

Here is a schematic that I developed for myself some time ago:

4

This circuit looks fairly good. Here are some notes that may help you.

The red X are actually wires in case you are not sure.

The LED and resistor above the switch can be removed, and a two lead Bi-polar LED can be put in series with the yellow wire (pin 8) or blue wire (pin 1) of the Tortoise. No resistor required.

If the signal works backwards, reverse the red and green wires on pins 5 and 6 of the Tortoise. If the signal does not light at all, reverse the black wire from the Tortoise pin 7 and the gray wire from the signal at the power supply. (reversing the voltage polarity to the signal) The value of the resistors used in the signal wires should be specified by the signal manufacturer.

5

Elmer,

Excellent clarifications. Thank you!

Rich

6

Rich,

I sure appreciate your drawing.

I think I wired it accordingly and the bipolar LED works but the Tomar signal would only light the red.

So I reversed the No. 5 and 7 wires into the Tortoise and now it works. Both greens light up in the LED and Tomar and when I flip the switch both reds come on.

I don’t know if I did something else backwards but it works and I didn’t blow up any LEDs.

Tony’s Train Exchange has a drawing for wiring a Tortoise to a signal (AN 6000-02) but I couldn’t figure it out.

Also want to thank you Elmer for your suggestion. I’ll try that one out.

7

Congrats and glad that the drawing helped.

Burning up an LED is always the risk in these projects, so you did good to avoid that issue.

Rich

8

I know I posted these before but since it has been mentioned to use a two wire bi-polar LED I thought it would be worth showing it again. I use these on my turnouts to indicate position and I also make the little housing for the LED to look like a prototype 'sort of ’ four light lantern. Just another method to accomplish the position indicator LED. The last two photos are the same turnout with each LED color shown.

-Bob

9

Bob, that is very, very cool. I had not seen this before on whatever thread you first posted it on.

Can you explain how you fashioned the lantern that holds the LED? What material did you use and how did you work it into the finished product?

Rich

10

Rich,

If you look at the first image I posted, the hand drawn diagram, I used some .03 and .06 styrene to make the body of the ‘lantern’ base. I drilled a hole to fit the bi-polar LED (3mm) and cemented it in from the bottom. I then painted it all flat black and then using a .06 dia drill, just spot drill four holes around the LED just deep enough to make a circular hole through the paint. This allows the light to come through in four directions, which looks like the prototype lantern, and reduces the glare from a bare LED. It has a very good effect. I would solder the power wires to the LED before mounting in the base.

I just made a new housing pattern and added bolt/washer castings to the four mounting holes and will be making a rubber mold and casting these for my layout (I need about 30 of them!).

Hope this is all clear,

-Bob

11

So, the lantern is merely the LED itself with a painted surface?

I cannot believe you can use a drill to make holes in the painted surface without breaking the LED.

Let me re-phrase that. I believe you. But, it astounds me.

After you make 30 for yourself, can I place an order with you to make approximately 60 more for me?

Rich

12

it’s actually not that bad – LEDs are plastic, so there’s nothing to “break” as with a standard incandescent lamp… granted if you drill too much (deep), then you might have problems…

13

Dan is correct, the LED is just a molded plastic that can be cut, trimmed and drilled (not to far in though!) to fit tight places or to reshape the ends. I even thought of molding the LED into the base but that is getting a little too complicated for a simple design. LED’s are cheap, about $0.10 each in quantities, althought the bi-polar ones are more, so you can afford to play around with them and see what you can do with them.

-Bob

14

Now that is really neat. [bow]

I wish I had thought of doing that! Very nice idea and thanks for posting it.

15

I agree. Bob, you need to patent that idea and then put it into production. I will be first in line.

Rich

16

thanks for all the kind words and comments. I actually thought about designing a prototype for production and seeing what it would cost to produce/sell. I will put it on my ‘to do list’ which is now about 3 years in the making!

-Bob

17

If you get an LED with a clear case and hold it up to the light, you can see the bits inside that make it work, including the whisker thin wire going fromt he smaller leg to the top of the larger terminal inside. That point of contact is the actual ‘diode’ spot. You can drill, sand, file, turn, etc LEDs all you want so long as you do not disturb that whisker wire and connection. One common thing to do where fiber optics is used is to drill straight down the top of the LED so the fiber cen be stuck into the LED and glues for better light transfer than just having the LED sitting behind the fiber.

–Randy

18

I finished the mold today and will try casting tomorrow. This is just a test model to see how the casting process works. Will keep you all posted on my progress.

—Bob

19

Bob,

Can you explain what we are looking at in that photo?

Rich

20

Rich,

Sorry for the lack of info on that. The upper photo is the pattern (brown item) that I glued to a piece of black plexi I had, which makes a good smooth surface for the mold as well. I built four walls around the pattern with some styrene strips (2 have been removed to get the mold out). I poured the silicone rubber into the mold box and when cured, removed it. The mold is in the lower photo.

I cast one part today but it didn’t come out too well, not enough material in the mold, so it was missing some of the edge details. I will try again and keep making adjustments until I figure this out. It is such a small part that I waste three times the casting material to get one part. The lower part of the base is only .030" thick and the casting material must have shrunk a little as it cured. I can see now that I would be better off with about four patterns (cavities in mold) so I could mix a small amount of casting plastic and fill all the mold cavities at one time. I will see where this goes?

-Bob