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Tortoise switch machines & bicolor LEDs

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Tortoise switch machines & bicolor LEDs
Posted by Anonymous on Saturday, July 15, 2006 12:26 PM
Hey Guys I have a question for those of you who have electrical know-how and experience with the Tortoise.
 
In the instructions under the section about panel lights and signals it mentions bi-color leds and states that you can wire these in reverse parallel so that when the switch is thrown it will indicate the direction of the turnout. How do need to go about doing this ??
 
I have a 12 volt power supply that I am using to control all switch machines by the way.
 
Fred

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Posted by rrinker on Saturday, July 15, 2006 1:41 PM
 For a bicolor LED, it's REALLY easy. I assume you have the 2-wire bicolor LEDs. Simply wire like this:

+ ------LED----tortoise----- -

+ and - not really mattering and in reality being the wires to your toggle switches that operate the Tortoise. No resistors are required, the Tortoise motor limits current to a safe 15ma that the LEDs can handle. If the LED is red when you want green, just flip the LED over.

                                         --Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Anonymous on Saturday, July 15, 2006 1:50 PM
Thanks Randy. I have have a habit of making things more difficult than they really are.
 
Fred

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Posted by claycts on Sunday, July 16, 2006 10:34 AM

 RockIsland4710 wrote:
Thanks Randy. I have have a habit of making things more difficult than they really are.
 
Fred

Thanks Randy ALSO,  I was using Grain of Rice but this sounds better.

George P.

Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by rrinker on Sunday, July 16, 2006 7:38 PM
 And if you want to have more than one LED - the LEDs do NOT go in parallel or anti-parallel like you wold when using individual LEDs. Bi-color LEDs you have to wire in series with each other and the Tortoise to have indicators at more than one spot. I was just working on a friend's layout this afternoon wiring up exactly such a thing. I also recommend a bunch of test leads with alligator clips to try it before you solder, because it gets a bit tricky.

+ ----|<--->|----(tortoise)----- -  will light one LED red and the other green. (bicolor leds don't have a anode and cathode technically, but these I was using actually had the flat and longer lead just like a normal single-color LED).  However, here is where it gets tricky. If the colors are backwards, you have to actually rewire it like this:  + ----->|-----|<----(tortoise)---- -  to swap which one is red and green - or swap the motor wires on the tortoise AND the physical position of the LEDs on the panel

This is ONLY in the case of wanting to use more than one LED. For just a single bi-color LED, There is no issue, just wire like my first post, and if the color is wrong flip the LED.

                                         --Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by TBat55 on Monday, July 17, 2006 5:39 AM

Where do you buy bi-color LEDs?  Radio Shack?

What size are they?

Thanks! 

 

Terry

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Posted by rrinker on Monday, July 17, 2006 8:46 AM
 You can get them at RS, if you want to pay too much. There are several sellers on eBay with stores (no bidding, just pay and buy) with LEDs at very reasonable prices. My friend got a pack of like 100 3mm size ones for $5. A better prices than RS but not quite that good - if your hobby shop deals with Miniatronics. Bi-color as well as ordinary LEDs come in many sizes, the common ones for panels at 5mm and 3mm, but there are smaller ones which can be used for lights and markers on locos and so forth.

                                            --Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by oleirish on Monday, July 17, 2006 10:24 AM

 rrinker wrote:
 You can get them at RS, if you want to pay too much. There are several sellers on eBay with stores (no bidding, just pay and buy) with LEDs at very reasonable prices. My friend got a pack of like 100 3mm size ones for $5. A better prices than RS but not quite that good - if your hobby shop deals with Miniatronics. Bi-color as well as ordinary LEDs come in many sizes, the common ones for panels at 5mm and 3mm, but there are smaller ones which can be used for lights and markers on locos and so forth.

                                            --Randy

Smile [:)] Randy:

I'am useing 5MM red and green leds with my tort machines with an 12vdc power supply I building an new "N" scale lay out and wounder?you said you did not need an resistor with your tort switch machines; would it besafe to go with out an resistor? I'am useing DPDT switches,It sure would be nice to get rid of the ---- resistor.

JIM

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Posted by Anonymous on Monday, July 17, 2006 11:59 AM

Here is an interesting site for Model Railroad LED's. I have ordered from them and have had great service. I am not affiliated with them in any way other than as a customer.

 

http://www.moreleds.com/railroad.htm

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Posted by wickman on Monday, July 17, 2006 1:29 PM

Just the kinda info I bin looking for TY .

One silly question though which contacts do you use off the tortoise for the led's and say if your using a green for a closed turnout indication and a red for an open turnout indication  on a route map board , which contacts would be used . I want to have 2 led's for each position of the turnout. I'm also using the digitrax ds64 to power and control the turnout on dcc digitrax hand controler ( not sure if this makes a difference) Big Smile [:D]

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Posted by rrinker on Tuesday, July 18, 2006 6:37 PM
 oleirish wrote:

 rrinker wrote:
 You can get them at RS, if you want to pay too much. There are several sellers on eBay with stores (no bidding, just pay and buy) with LEDs at very reasonable prices. My friend got a pack of like 100 3mm size ones for $5. A better prices than RS but not quite that good - if your hobby shop deals with Miniatronics. Bi-color as well as ordinary LEDs come in many sizes, the common ones for panels at 5mm and 3mm, but there are smaller ones which can be used for lights and markers on locos and so forth.

                                            --Randy

Smile [:)] Randy:

I'am useing 5MM red and green leds with my tort machines with an 12vdc power supply I building an new "N" scale lay out and wounder?you said you did not need an resistor with your tort switch machines; would it besafe to go with out an resistor? I'am useing DPDT switches,It sure would be nice to get rid of the ---- resistor.

JIM



 I can't draw it all here neatly in text (I'm sure there is a fixed tag though that would make it work). However, what you would do is wire the LEDs back to back. One red, one green, or both red, or whatever colors you want. By back to back I mean this. On the LED you will notice one lead longer, and also (usually) a flat spot on the side of the LED. Connect the long lead of one LED to the short lead of the other. Connect the short lead of the first LED to the long lead of the other. If you want to test - get a 1K resistor and a 9V battery. Go from + on the battery to one of the paired leads. GO from the other pair of leads to the 1K resistor. Connect the other side of the resistor to the - terminal of the battery. One of the LEDs should light. Reverse the battery. The other LED should light. If you, you're good to go.
 If you are using DPDT switches, I assume you have them wired with an X on the back. Two wires from one end will run to your power supply, to wires from the middle will run to pins 1 and 8 on the Tortoise. It does not matter which one, my example will say Pin 1 on the Tortoise. Break the wires leading to Pin 1 of the Tortoise. Connect one of the paired LED leads to the switch side of this break. Connect the other paird leads to the Tortoise side. You do not need a resistor here. Just the LED. Since the LEDs are in series with the Tortoise, they will receive the same current as the Tortoise motor, which is about 15ma stalled. And 15ma is just right for LEDs. Now apply power - one LED will glow. Throw the toggle, the Tortoise will move, and the other LED will glow. If they are the wrong colors, flip over the LED combo and reconnect.

                                   --Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by claycts on Thursday, July 20, 2006 8:45 PM

Randy, I went with the Bicolor LED and it is BETTER than I had hoped for. Gives me a LOCAL indicator at the turnout (dwarf) and now the LED at the DPDT without using the tortise connection.

THANK YOU!!!!

Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by claycts on Thursday, July 20, 2006 8:58 PM
 caellis wrote:

Here is an interesting site for Model Railroad LED's. I have ordered from them and have had great service. I am not affiliated with them in any way other than as a customer.

 

http://www.moreleds.com/railroad.htm

Charlie, Thank you for the link. Got all my LED's for $30.00 (150 of them)

Take Care George Pavlisko Driving Race cars and working on HO trains More fun than I can stand!!!
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Posted by Modeloldtimer on Friday, July 21, 2006 10:46 AM
Here's a link to a dirgram for the hookup of LEDs to a Tortoise Switch Machine.

http://www.tonystrains.com/technews/tortoise/wiring-leds.htm



Modeloldtimer

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Posted by ShadowNix on Sunday, July 23, 2006 7:45 AM

Hello,


The site below is great for wiring... as it explains, if you have a bicolor diode you just substitute for the R/G 2 parallel LED's.  I have done it and it works great... I did NOT know you did not need the resistor until a few weeks ago (time to take them out!), but that is a good thing to too know.... enjoy.

http://www.wiringfordcc.com/sw_ctl.htm

Brian

"That which doesn't kill you makes you stronger!"
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Posted by johncolley on Tuesday, July 25, 2006 9:53 AM
Here is a setup that sounds way more complicated than it actually is, and after you do the first set, is so easy! I am doing Free-mo modules, which are viewed and operated from both sides, so, remembering the old days of blocks and DC I run 12vdc power to the sides of a DPDT on-on switch (not center off, although you could use them if that's all that you can get), use the reversing crossover  wiring, run to the other DPDT switch, also crossed over. From the sides of the second switch I run the - to a 2 terminal block. I run the + to 2 bicolor LED's in series then to the other terminal. On the other side of the terminal block I run to the tortoise. If it is indicating backwards to what I want I just change the Tortoise connections at the terminal block....easy! Now I have an LED over each switch, and throwing either one changes the point throw and the LED color.
jc5729
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Posted by Uptown on Tuesday, September 12, 2023 11:05 AM

I don't care what is said, but you will need to use a 1k ohm resistor with a 5mm bi polar led with a tortise switch machine.  After 10 blown leds not using a resistor proves others wrong about not using a resistor with a tortise.[quote user="Anonymous"]Hey Guys I have a question for those of you who have electrical know-how and experience with the Tortoise.
 
In the instructions under the section about panel lights and signals it mentions bi-color leds and states that you can wire these in reverse parallel so that when the switch is thrown it will indicate the direction of the turnout. How do need to go about doing this ??
 
I have a 12 volt power supply that I am using to control all switch machines by the way.
  

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Posted by gregc on Tuesday, September 12, 2023 5:41 PM

Uptown
How do need to go about doing this ??

see panel 4 

greg - Philadelphia & Reading / Reading

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Posted by gmpullman on Tuesday, September 12, 2023 8:29 PM

Uptown
I don't care what is said, but you will need to use a 1k ohm resistor with a 5mm bi polar led with a tortise switch machine.

Welcome Uptown

I have about 115 Tortoise machines on my layout. They all have at least one LED in series with the operating lead (term. 1 or 8). Some have up to four LEDs in series.

Not a single resistor is used. None of the Tortoises have failed in the 28 years or so they have been in use. Occasionally I'll get a bad LED. The ones available to us through the secondary market are probably not of 'first quality' runs but most likely those that have not passed muster in QC tests.

    Good Luck, Ed

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Posted by CharlieM on Tuesday, September 12, 2023 9:58 PM

Uptown

I don't care what is said, but you will need to use a 1k ohm resistor with a 5mm bi polar led with a tortise switch machine. 
 

FWIW an additional resistor IS NOT required if the back-to-back LEDs are wired in series with the Tortoise motor (pins 1 & 8). The motor measures 730 ohms which limits the current through the LEDs to about 12 milliamps, assuming 3V LEDs and a 12V supply. This is a very safe current for LEDs. In fact, adding a 1KΩ resistor in series will cut the voltage to the Tortoise and slow it way down. Not good or necessary.

 

That said, today’s super bright LEDs are very efficient and are way too bright for me at 12ma. In addition, the different color LEDs vary in brightness for the same current. That makes the green LEDs very bright and the red ones less so. Straight back-to-back hookup gives no opportunity to individually adjust the brightness. A better way is to wire the LEDs in parallel with the Tortoise motor and use separate resistors of differing values in series with each LED. The full 12V is applied to the motor and the LEDs can be individually adjusted for optimum brightness. The exact resistor values must be determined experimentally due to your own preference and LED characteristics but starting values are 33K for red and 220k for green. These values may seem very high compared to the conventional 1K values but these newer LEDs, available today from various suppliers, are really bright. I don’t need my control panels to shine like miniature suns when I turn out the lights for night running Cool.
 
Charlie - Northern Colorado

 

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Posted by hon30critter on Wednesday, September 13, 2023 2:01 AM

CharlieM
That said, today’s super bright LEDs are very efficient and are way too bright for me at 12ma. In addition, the different color LEDs vary in brightness for the same current. That makes the green LEDs very bright and the red ones less so. Straight back-to-back hookup gives no opportunity to individually adjust the brightness. A better way is to wire the LEDs in parallel with the Tortoise motor and use separate resistors of differing values in series with each LED. The full 12V is applied to the motor and the LEDs can be individually adjusted for optimum brightness. The exact resistor values must be determined experimentally due to your own preference and LED characteristics but starting values are 33K for red and 220k for green. These values may seem very high compared to the conventional 1K values but these newer LEDs, available today from various suppliers, are really bright. I don’t need my control panels to shine like miniature suns when I turn out the lights for night running .

Hi Charlie,

Thanks for bringing up the LED brightness issue.

Please tell me if I understand this correctly. I have designed my Tortoise circuits to use bi-colour two pin red/green LEDs in series with the Tortoise motors for both panel indication and signals. If I want to control the brightness of the individual colours does that mean that I should be using three pin LEDs so that I can attach different resistor values to each of the colours, and then wire the LEDs in parallel with the motors? If so, does it matter if I am using common anode or common cathode LEDs?

Also, I have ordered an 18v DC power supply to drive the Tortoises because there will be five or six LEDs in series with each Tortoise. If I wire the LEDs in parallel I assume that I should only use a 12v power supply. Correct?

I apologise if I am asking obvious questions but I have very little understanding of electronics. I can build a circuit from a plan, but please don't ask me to explain how it works.Dunce

Thanks,

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by CharlieM on Wednesday, September 13, 2023 9:17 AM

Dave,

You are correct. If you use the 2-pin combination you are stuck with the existing brightness at full current and the different brightness levels. Simple to wire but not to pleasing to my eyes. The 3-pin versions are readily available:

https://www.amazon.com/EDGELEC-Bi-Color-Diffused-Resistors-Included/dp/B077XBW2JG/ref=sr_1_3?crid=2N41PJKWMDP09&keywords=bicolor%2Bled&qid=1694613552&sprefix=bicolor%2Caps%2C145&sr=8-3&th=1

I prefer the common cathode just because my brain thinks that way. Just put the appropriate resistor in series with each anode and connect the free end of the resistors to the appropriate sides of the Tortoise motor (pin 1 or 8). Connect the common cathode to the negative side of the power supply. Common anode configurations can also be used but the anodes are connected to the positive of the power supply. Please excuse the dissertation but this forum does not support direct image upload.

The above assumes you are using a single 12V power supply. The Tortoise is rated at 12V max so it looks like you’re in the market for a new 12V power supply. Again, readily available. If you’re using dual polarity power supplies I think you can still use 3-pin configurations but I’ll have to refill the coffee mug and cogitate on it a while.

Charlie – Northern Colorado

 

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Posted by hon30critter on Wednesday, September 13, 2023 10:14 PM

CharlieM
Just put the appropriate resistor in series with each anode and connect the free end of the resistors to the appropriate sides of the Tortoise motor (pin 1 or 8).

Hi Charlie,

I'm not sure how the resistors should be connected to pins 1 and 8. I have attached a diagram showing the circuit as you descibed it (I think) but I have not connected the resistors to Tortoise.

I am going to use 560 ohms for the green LEDs and 1K for the red as a starting point. Those values were what was recommended by RR Mel (RIP) for getting even brilliance for tri-colour LEDs (I'm using bi-colour) but that was several years ago.

Thanks for your help. I really appreciate it. I hate seeing LED signals that are so intense that they leave spots in your eyes.

Cheers!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by CharlieM on Thursday, September 14, 2023 9:43 AM

Dave,

 

Your diagram is correct as far as it goes. Since you are using two (or more) panels in series the toggle handle positions do not accurately reflect the Tortoise positions. To have the LEDs on each panel display the true Tortoise position you have to connect the LEDs to the Tortoises themselves electrically. You need to connect all the LED pairs together and connect the combinations to the Tortoises. This can be done right at the Tortoises or at the last control panel. For example, connect all the 1K resistors together and connect them to pin 1 of either Tortoise or the purple wire leaving the South control panel. Similarly, connect all the 560 resistors together and to pin 8 of either Tortoise or to the gray wire leaving the South panel. If the wrong color LEDs light just reverse the pin1- pin 8 connections. Your serial DPDTs complicate the wiring but it’s doable.

Your chosen resistor values seem low by my experience and I’ve found the green LEDs are usually much brighter than the red ones. This may be just the particular LEDs I’m using. Try what you suggest and just experiment until they suit you.

 
BTW the eye spots will fade with time and enough operating. Press on.

 

Charlie – Northern Colorado

 

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Posted by hon30critter on Thursday, September 14, 2023 6:51 PM

Hi Charlie,

Thank you for clarifying the Tortoise connections. I had guessed that was the way the LEDs would be fed but it took me a long time to figure it out. Like I said, I can build a simple circuit if I have a diagram but I barely understand how they work.

Cheers!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by CharlieM on Thursday, September 14, 2023 9:49 PM

Dave,

I think you may be selling yourself short. Your diagram indicates you do have a basic understanding of what's going on. BTW, what program are you using to generate the schematic. It looks quite professional. I use CadRail for all my layout, benchwork, track plan and schematic work as well as general purpose CAD stuff. Don't know how I ever got along with paper, pen and drafting set, but I did Wink

Charlie - Northern Colorado

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Posted by hon30critter on Thursday, September 14, 2023 10:53 PM

Hi Charlie,

I am using 3rd Plan It to create the schematics. I love the program! I have used it for so many things not related to model railroading.

As far as me understanding electronics, I have been able to figure things out but I had a lot of help along the way. It is not intuitive for me.

Thanks again for your help!

Cheers!!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by HO-Velo on Saturday, September 16, 2023 1:17 PM

CharlieM
If you use the 2-pin combination you are stuck with the existing brightness at full current

I got stuck with overly bright bi-color two pin LEDs and went with a low-tech solution in dimming them down; punched out some wafers from thin white sheet styrene and attached them to the bezel faces with canopy cement.  

Regards, Peter   

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