I’d like to mount Bicolor LEDs to the tortoise for the control panel, so that the ‘open’ track is always green and the ‘closed’ track red.
Since 2-lead bicolor led’s change color based on currnt flowing to + or -, I believe the traditional wiring of them would result in this (since one will always have current to - and the other current to +… But I’m no electronics whiz…
Any thoughts on this? Here’s the typical hookup…
there are two ends to the standard LED…the anode and the cathode…if you are using bi-colored LED’s you will have to wire it differently than the picture using terminals 2, 3, and 4 of the tortoise…so… the center lead of the bi colored LED will go directly from a constant D/C power souce of your power pack to the center post of the LED (be sure there is at least a 280 - 560 ohm resistor in this wire between the pack and the LED)…now…the other lead from the power pack will go to terminal 4 on the tortoise machine…then…run a wire from terminal 2 to the left lead on the LED and another wire from terminal 3 to the right lead of the LED…if it lights opposite of what you want, change leads 2 and 3 around…wire the motor (terminals 1 and 8) directly to your DC power source eliminating the LED’s shown in the drawing…the bi colored LEDs i use have three prongs if that’s what you are getting at…chuck
Yes, that will work as drawn. Throw to the right, one LED will be green and the other red. Throw to the left, and the red LED will now be green, and the green LED will now be red.
If you are using this for signals, that’s fine, but for panel lights, USUALLY only the selected route is lit, to avoid confusion (even with 2 different colors). But, it will work as you state.
–Randy
i’ve never seen or experienced a bi-colored LED with only 2 prongs…mine are all three post bi colored LED’s…unless i’m missing something…is there such a thing?..anyway…my earlier post is how i wire them using the three pronged LED type…chuck
CW - Yeah, I found them from miniatronics at http://www.tonystrains.com/products/mini_leds.htm
Apparently the color changes just from polarity.
Two-lead bi-colour LEDs depend on the polarity of the current. Wire them in one way, they’ll glow red, wire them “backwards” and they’ll glow green. Actually, there’s two LED elements inside, a red one and a green one, and they’re wired side by side but pointing in the opposite directions.
Three-lead bi-colour LEDs again have two elements inside them, but one lead from each is wired together and brought out to the common lead, the other lead from each element is brought out to a separate lead. There are two variations to this–common anode and common cathode. With the common anode version, the common lead is connected to + voltage and the other two leads are connected to - voltage, whichever one you want to shine. With the common cathode version, the common lead is connected to - voltage and the other two leads are connected to + voltage, whichever one you want to shine.
Hope this helps you figure out how to connect your LEDs to your Tortoises.