Model Train-related Notes Blog -- these are personal notes and musings on the subject of model train control, automation, electronics, or whatever I find interesting.
2020-03-15 - Dwarf Signal for Turnout, ContinuedCategory Train
Here’s a concrete example that shows how to wire LEDs directly to a turnout frog, as explained here, and makes it obvious how trivial this is:
Resistance used here is 1 kΩ, that gives good brightness for both the green and red LEDs.
A 2.2 kΩ resistance also worked well enough for the red LED yet made the green one too dim.
Another variation of this that I plan to use on the Randall Model Train layout is to only have the red LED, to make it clear when a turnout is left thrown/divergent. Especially for mainline turnouts, it acts as a “warning” signal. There is no need for the green LED in that case. I will likely embed the LED directly next to the turnout in the ballast. These LEDs are small enough that they could even be placed between the ties.