Really basic control panel wiring question

[quinntopia]

Okay, I'm not an electronics guy at all, so this is sort of dumb question for a really basic wiring question.

 

Here's the scenario.  I have a couple of sidings that are typically used for storage.  In order to reduce power consumption on these sidings I've decided to isolate one of the rails and use a switch on a control panel to power the isolated rail.  What has me stumped is how do I wire up an LED on the control panel that would indicate when the power is 'on'?

 

The dumb thing I did on my first try (without thinking too much about it, not a good idea with electronics!) is that I wired an LED with a resistor to the Normally Off (?...just using an SPST at the moment) side of the switch so that when you flip the switch to the isolated rail, the LED turns on.  Oh, I wired this into the wire that is the return to the isolated rail so the track only receives like 3v @ 22ma!  Hah! That's not going to do much.  So clearly, the resistor/Led can't be inline with the return, but there has to be simple way to do this, right?

[KenS]

The first problem you're going to have (unless you use DCC), is that no power is flowing unless the throttle is set to move the train, so the light will be off if the train is parked.

 

If I'm reading you right, you wired the LED in series with the load on the track, in other words in line with the wire to the track (so voltage has to flow through the LED to get to the train).

 

What you need to do is run the LED (with a resistor to drop the current from 12-16v down to a safe level) in parallel with the train, not in series.  In other words, between the two rails (or the wires, as long as you connect to the switched wire between the switch and the track; i.e., after the switch, not before).  Then, when there's voltage on the rail, some will go to the LED, and the rest to the train (it won't get as much as without the LED, but if you use a low-voltage LED and a big resistor, it should have enough to move in and out of storage).

 

Me, I'd use a DPST (dual pole) switch, and wire the LED independent of the track wiring, to a separate power supply, so a thrown switch controls the LED regardless of what voltage on the track.  After all, it's the switch position you care about, not whether the throttle is turned on.

[quinntopia]

Thanks Ken! That is exactly what I was looking for! 

[quinntopia]

Well, I got my electrical problem sorted out...thanks Ken for the tip!  As it turns out, one of the leads wasn't connected... :BangHead:!!!

 

And here's what the control panel (for my top loop anyway) looks like:

This replaces 6 of the big blue Kato switches, which was always confusing as I could never remember which switch went with each turnout!