I have wired up a dwarf green/yellow signal using the tortoise internal switch. The yellow works, but the green does not light when it should. However, when you throw the turnout back to yellow, it glows green for half a second, then turns yellow. I have tested all connections and am lost as to a solution.
Are you using a tri-color LED? Those have three leads: a green anode, a red anode, and a common cathode. They light green if current is applied to the green anode, red if current is applied to the other, and yellow if current is applied to both. The way the contacts work on a Tortoise is they turn on or off depending on which way the switch motor is lined. So if your dwarf signal uses a tri-color LED and is usually yellow no matter which way the Tortoise is lined, that means you've wired it so both anodes are getting current all the time (except when the red anode's current is temporarily broken during the throw process). With a tri-color LED, you don't need to use the Tortoise's internal switches -- you can do so, but it requires more wiring. Instead, connect both anodes of the LED in series to one of the leads powering the Tortoise, and run the common cathode to ground. If the current is flowing in one direction, the LED will light red; if flowing the other way, it will light green. According to the instruction sheet that comes with the Tortoise, you don't even need resistors for the LED. See wiring diagram 4 on the instruction sheet that came with your Tortoise (you can also download it here).
--Steven Otte, Model Railroader senior associate editorsotte@kalmbach.com
Thanks for the response. No, it is a prewired dwarf signal with two LEDs, green and yellow. It has a green and yellow cathode wire and a black anode wire. I will try it without the resistor and see if that may be causing the problem.
Mac49 Thanks for the response. No, it is a prewired dwarf signal with two LEDs, green and yellow. It has a green and yellow cathode wire and a black anode wire. I will try it without the resistor and see if that may be causing the problem.
I wouldn't do that! If the resistor was pre-wired into the signal, it's probably necessary to keep the LEDs from being burned out.
Do not remove the resistor, you will create a dwarf flashbulb signal as the LED flashes brightly for a millisecond and then goes pop.
How do you have it wired? The if the black wire is a common anode, that should go to the + of your signal power supply. The yellow and green wires should go to pins 2 and 3 OR 6 and 7. The - of the power supply should go to 4, if the green and yellow are on 2 and 3, or else 5 if the green and yellow are on 6 and 7. If the wrong LED lights up, swap the green and yellow wires.
If you are trying to use the method of putting the LEDs in series with the Tortoise power on pins 1 and 8, you cannot do that with a 3 lead signal like that (at least not in a simple fashion).
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
What are you using to power the Tortoise?
I use a DC power pack. The white wire from the dwarf connects to the DC power pack and the green and yellow dwarf wires connect to the Tortoise - - but not the outer terminals on the Tortoise. You need to use the internal Tortoise switches to connect to the green and yellow dwarf wires.
To complete the circuit, you need to wire the other side of the DC power pack from whatever is throwing your turnout points. I use a DPDT toggle switch.
As others have said, leave those resistors in place.
Rich
Alton Junction
Thanks, everyone. I was trying to use the same power source that was powering the tortoise (#1 and #8) and that was the problem. I just wired it to a separate signal power bus and everything works!
Mac49 Thanks, everyone. I was trying to use the same power source that was powering the tortoise (#1 and #8) and that was the problem. I just wired it to a separate signal power bus and everything works!
Signals can ALWAYS connect to the same circuit as the Tortoise. In case of LION, one leg is always GROUND and LION just uses one wire to control the tortoise and signals, but that matters knot.
Just put your signal circuits in PARALLEL with the Tortoise and not in series with it.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS