Tomar Searchlight Signal LEDs

[Southwest Chief]

I have a few Tomar searchlight signals on my layout and just love the way they look and operate. But I've always wondered how Tomar is able to get three colors from one LED.

If you wire it correctly you can have red, amber, and green. The red and greed are like any other bi color LED (polarity one way makes red, polarity the other way makes green. But if you combine the wires you get amber. I probably didn't describe this right, but I know they work like this. I just can't figure out how they work and why other manufactures don’t duplicate this. Anyone know how these LED's work? And what are your thoughts on Tomar signals?

Sure can’t beat properly operating signals. Now if I can only find a detection system that will operate a few blocks, and have dark, and flashing amber aspects in addition to the red, amber, and green.

[grandeman]

The Bi-Polar LED's color is determined by which leg is powered. If both are powered, red and green make yellow. There's 2 pin and 3 pin bi-polar LEDs.

Signals are WAY cool. We don't have any Tomar, most of our are semi-scratched. Here's the way we do them. http://www.trains.com/community/forum/topic.asp?TOPIC_ID=51410

As for block electronics, give this a try. url]http://home.houston.rr.com/lrt/[/url]

[Don Gibson]

TOMAR makes the signal, not the 'engine' to run it.

I have a 'Dummy' Tomar fed by a toggle SPDT to show red or green. To have OPERATING signal's require's some 'pricey' electronic's which require Detection and Operation circuit's.

http://www.integratedsignalsystems.com/electronics/Default.htm

WORD to wise: TWO aspect (red / green) is cheaper than THREE (red lellow green)