Hi there
I have read a couple of posts in this forum regarding this matter and also have the diagram from Circuitron showing the connection, but as that diagram is for 2 LED's I was hoping you guys could kindly clear up a couple of questions I have regarding connecting 1 LED.
Firstly, from my understanding the center poles of the DPDT switch should be connected to Terminal 1 and 8 of the Tortoise and one of the pair of end poles should be connected to the switch machine power supply. Is my understanding correct ?
Additionally both pairs on end poles should be cross connected.
Secondly, from the Circuitron diagram it seems the LED should be wired between the Tortoise and the DPDT panel switch.
Now this is where I am a little confused as the diagram doesn't explain how to connect to the DPDT.
If I am only using 1 LED ( and again referring to the Circuitron diagram) which leg of the LED is connected to Terminal 1, long leg or short leg ? Once that has been established, where does the remaining leg of the LED get connected to ? The DPDT ?
As I said, I can see ( well, sort of ) how this is all supposed to work but am still a little confused.
If someone would be good enough to hold my hand and walk me through this I would be greatly appreciative.
My intention is to use a bi-color LED. Will a resistor be needed ? The Circuitron diagram seems to think otherwise.
Many thanks in advance
cheers
Be careful when hooking up to a circuit that has a coil on it. When voltage is removed from the tortoise it may kick back and blow an LED. They may have protection circuits to prevent this but I don't know enough about them.
Springfield PA
bagman Secondly, from the Circuitron diagram it seems the LED should be wired between the Tortoise and the DPDT panel switch. Now this is where I am a little confused as the diagram doesn't explain how to connect to the DPDT. If I am only using 1 LED ( and again referring to the Circuitron diagram) which leg of the LED is connected to Terminal 1, long leg or short leg ? Once that has been established, where does the remaining leg of the LED get connected to ? The DPDT ?
The LED does go between the Tortoise and the switch. On leg of the LED to the Tortoise, the other to the wire coming from the switch.
In order to say which legs goes where, you'd need to know the polarity. It's pretty easy just to put it in one way and try it. If it lights RED when the turnout in in the position you want it, you're done. If it lights incorrectly, just turn the LED around. And no, you do not need resistors. When you get it hooked up you'll see that the LED sort of dims while the Tortoise is moving. After it stalls and the low current stabilizes, you'll have a nice steady glow. With the bi-color LED, color will depend on what direction the Tortiose is in.
I use bi-colored LEDS on by panel, hooked up as Steve describes. Green for straight and red for divergent. One of the leads off the LED is longer than the other so positioning the LED to the correct color to match the turnout position is easy. just put it in line with one of the wires leading to the turnout from the toggle, and you are good to go.
Hi guys
Thank you for replying.
I'm still a little confused though. When you say conenct 1 leg of the LED to the Tortoise, which terminal of the Tortoise ?? T1 or T8 ?
I assume when you say to experiment with the wiring to get the right color for the appropriate leg of the turnout you mean changing the connection to the DPDT ??
Appreciate your replies
Either 1 or 8, it doesn't matter. If the wires from 1 and 8 to your DPDT switch are correct currently, cut one and insert the LED. The experimentation comes in if the LED is the wrong color, just flip it around. If you change the wires at the DPDT switch, it will change the LED, but it will also change which way the Tortoise motor moves.
When hooking up a new one:
If the toggle and the tortoise match but the LED is wrong, flip the LED
If the LED and the toggle match, but the Tortoise is wrong, flip terminals 1 and 8 on the Tortoise
If the Tortoise and the LED match but the toggle is wrong, flip the leads on the toggle.
If everything matches first time, you're darn lucky, move on to the next one.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi Randy
Am I right in thinking that T1 and T8 from the Tortoise should be connected to the center pins of the DPDT ( the DPDT has no center off ) ???
Sorry to be such a pain, but when you say " cut one and insert the LED " are both legs of the LED wired to the same wire coming from the Tortoise ?
So in other words, I have T1 and T8 wired to the center pins of the DPDT. As you suggest, I cut one of those wires ( say the one coming from T1 ) and connect both legs to the same wire, connecting nothing to the wire coming from T8 ?
Appreciate your patience in answering my questions.
update:
Taking another look at the wiring diagram from Circuitron I think I understand now.
I should run one wire from one side of the center poles on the toggle switch straight to the tortoise pin 8, and run a wire from the other pole of the toggle switch to one leg of the LED, and then another wire from the other leg of the LED to pin 1 of the tortoise. Is this correct?
Switching around which leg of the LED is wired to Tortoise/DPDT will give me the correct lighting option of Green for main/Red for diverging leg.
Your followup has it correct. You can also change the indication of the LED simply by changing which leg of it connects to pin 1 of the tortoise and which leg of the led connects to the toggle.
Thanks Randy
Appreciate all the advice, and the time you guys take, to reply.
If you plan on using only one LED in series with the Circutron machine, you will have to put a conventional diode (1n4001, etc.) oriented backward from the LED, across the LED to allow current to flow in the other direction. Current can only flow in one direction thru an LED. In the opposite direction the LED looks like an open...no current will flow.
larsend If you plan on using only one LED in series with the Circutron machine, you will have to put a conventional diode (1n4001, etc.) oriented backward from the LED, across the LED to allow current to flow in the other direction. Current can only flow in one direction thru an LED. In the opposite direction the LED looks like an open...no current will flow.
Bi-color will flow current in both directions. In one direction, green lights, reverse the current, red lights.
No extra diodes required.
http://ezbizwebsite.com/EbayTrainPix/Signals%20and%20Power/Tortoise%20instructions%20compared.pdf
on page 5 there are several diagrams at the bottom. use the far left one right above the words "PANEL LIGHTS/SIGNALS". simply splice the LED (not shown on the diagram) into either of the wires connected to the tortise #1 or #8. the LED will serve as the resistor and NOT cause harm to the tortise.
if the tortise moves the wrong way when the DPDT is thrown, reverse the #1 and #8 on the tortise. if the LED is the wrong color for the direction, reverse the LED connections.
Yea, I was thinking of the bi-color LED as two LEDs in one case!
larsend Yea, I was thinking of the bi-color LED as two LEDs in one case!
That's what they are. In the versions with just two leads, the two different colors are wired back to back. Current flows one way, it lights up one color, change polarity, it lights up the other color.