LED power indicator for individual blocks.......

Just use a 1K resistor and a diode like the 1N4003 in series with the LED bulb, that connects directly across the track power.

OK, as usual, I was over thinking the situation! Thanks John.

Yep, some problems are best addressed with the simple method.

Is the 1k resistor enough for a red led?

@John H posted:

Is the 1k resistor enough for a red led?

If you get a 14 volt red color led with a 300k resistor same thing.

I have 2mm red leds rated at 1.8 to 2 volts, thus my question.

@ThatGuy posted:

If you get a 14 volt red color led with a 300k resistor same thing.

A 300k resistor will barely light the LED at all and you'll likely not even see it!  With 18 volts, the average current to the LED will be 25 microamps since it's only lit on a half cycle.  How in the world did you come up with 300K?

@John H posted:

I have 2mm red leds rated at 1.8 to 2 volts, thus my question.

With a 1K resistor, and a red LED, you'll have about 8ma of average current, way below the 20ma rated current of the red LED.

@gunrunnerjohn posted:

A 300k resistor will barely light the LED at all and you'll likely not even see it!  With 18 volts, the average current to the LED will be 25 microamps since it's only lit on a half cycle.  How in the world did you come up with 300K?

With a 1K resistor, and a red LED, you'll have about 8ma of average current, way below the 20ma rated current of the red LED.

Used them for years, the tolerance of the LED is amazing. I used the 14v version just because I use them in place I do not use the resistor in.

@ThatGuy posted:

Used them for years, the tolerance of the LED is amazing. I used the 14v version just because I use them in place I do not use the resistor in.

With all due respect, you have no idea what you're talking about.  Tolerance?  There is no doubt that an LED will tolerate 25 microamps, it hardly notices it!  We making an indicator light, presumably one that will be relatively easy to see in normal room light.

Here's two red LED's both powered from 18VAC, one with a 1K resistor and the other with a 300K resistor.  In normal room light, the one looks completely dark, guess which one has the 300K resistor?

So, I turned off the bench lights and the other LED, and sure enough, there is a very dull glow that you can barely see, it is actually lit slightly with 25 microamps.

I'll leave it up to @John H which resistor value he thinks is appropriate for his indicator lights.  I'm betting it'll be the one that he can actually tell is lit!

All I can say is you must have Eagle Night Vision to be able to use that as a pilot light!

@gunrunnerjohn posted:

With all due respect, you have no idea what you're talking about.  Tolerance?  There is no doubt that an LED will tolerate 25 microamps, it hardly notices it!  We making an indicator light, presumably one that will be relatively easy to see in normal room light.

Here's two red LED's both powered from 18VAC, one with a 1K resistor and the other with a 300K resistor.  In normal room light, the one looks completely dark, guess which one has the 300K resistor?

So, I turned off the bench lights and the other LED, and sure enough, there is a very dull glow that you can barely see, it is actually lit slightly with 25 microamps.

I'll leave it up to @John H which resistor value he thinks is appropriate for his indicator lights.  I'm betting it'll be the one that he can actually tell is lit!

All I can say is you must have Eagle Night Vision to be able to use that as a pilot light!

I’m am not gong to argue with you, you know it all and have complex ways to do it. If that works for you great, if not great. So all the leds I have install and lit nicely must be mistakes. I will ask the people who had me covert engines/passenger cars/signals please stop using them they don’t work. Thank you for the clarification.

There's nothing complex about lighting an LED.  I have no doubt you have some LED's that are lit, but I can assure you they aren't using 300K resistors with an 18 source voltage if you plan on seeing them in anything but total darkness.

@gunrunnerjohn posted:

There's nothing complex about lighting an LED.  I have no doubt you have some LED's that are lit, but I can assure you they aren't using 300K resistors with an 18 source voltage if you plan on seeing them in anything but total darkness.

No worries.

Wouldn't a 14 volt led have to already have a resistor and diode to work? Maybe it's a 300 ohm resistor we're talking about. How about a picture of this led?

"Complex ways."  Are you referring to Ohm's Law? 

I checked 14v red LED bulbs on Mouser. That list showed a range of current from 10mA to 50 mA. Resistance values from 360 ohm to 1.8 Kohms at 18 v. I don't think you have a resistor of the value you think you have.

Not sure if the OP is using Fastrack, but has anyone tried drilling a hole in the roadbed of each block of Fastrack and putting a prewired LED in it connected to the track from underneath?

John

@Craftech posted:

Not sure if the OP is using Fastrack, but has anyone tried drilling a hole in the roadbed of each block of Fastrack and putting a prewired LED in it connected to the track from underneath?

John

Hi JOHN,

  That is what I did with the pre wired LEDs.  I used the LED and fed it through a brown pipe, the kind that Lionel use to give with its starter set.  I then drill hole through table feed it through add wire, if needed, along with two of the .110 female clips then attach to Fastrack.  Simple easy and they have worked great for five years.

@Craftech posted:

Not sure if the OP is using Fastrack, but has anyone tried drilling a hole in the roadbed of each block of Fastrack and putting a prewired LED in it connected to the track from underneath?

John

I did these for sidings when I was using Fastrack.  The yellow LED indicated power on the siding.  For simply illuminating blocks, you could forget the switch and just use the LED with the resistor and diode, that's what's in the black heatshrink.

@John H posted:

Wouldn't a 14 volt led have to already have a resistor and diode to work? Maybe it's a 300 ohm resistor we're talking about. How about a picture of this led?

John, I think we've beat this horse to death.  I think you'll be happy with my recommendation of the 1K resistor and diode.

@gunrunnerjohn, you're right. Thanks.

@gunrunnerjohn posted:

I did these for sidings when I was using Fastrack.  The yellow LED indicated power on the siding.  For simply illuminating blocks, you could forget the switch and just use the LED with the resistor and diode, that's what's in the black heatshrink.

Very cool trick

FWIW, I just put together a siding switch panel for a train friend here in Az, using pre-wired 3 mm leds bulk purchased from Asia. They come with a push in 1/4" plastic bezel and a 500 ohm inline resistor and are rated for 12 vdc.

I did some testing and at 12vdc they run at 20 ma as expected. Connected to 18 vac with a common blocker 1N4003 diode inline on the ground return side, they run at 17 ma current. They are connected to the NO side of each siding switch so they only light when the siding actually has power. He can run both command and conventional with this setup. He is quite happy with it so far. I can post the wiring diagram, though it is pretty simple!

Rod

Would be great to see the diagram and picture of the finished product.  👍🏼

Not rocket science here, for an LED from track power, complete with reverse voltage protection for long life, here it is.  The resistor value of 470 will give you an average current of close to 20ma with 18 VAC track power, I typically use a 1K resistor to cut that to half as the LED's are more than bright enough with half the current.

Here's my illuminated yard switches, these LED's each have a 1K resistor and all of the LED's have a single diode to the track common for reverse voltage protection.

You can add as many LED resistor pairs to a single protection diode as you need, especially if they're in one place.  Just keep stacking them up.

Here is the wiring diagram and a picture of the finished panel. It's not a fancy panel like grj's, but hey, it gets the job done. Note that there are 6 switches currently wired, with provision for two more.

The blocker diode on the right is wired using a euro terminal strip, just for convenience. Originally I had considered maybe needing an additional inline resistor as shown, but later decided there was no need. The leds are nice and bright running command at 18 volts, but somewhat less so running conventional. And of course in conventional they don't light at all until you have some track voltage.

Hope that helps, Rod

@gunrunnerjohn posted:

I did these for sidings when I was using Fastrack.  The yellow LED indicated power on the siding.  For simply illuminating blocks, you could forget the switch and just use the LED with the resistor and diode, that's what's in the black heatshrink.

Nice.  What was the rating of the toggle switch?

John

@laz1957 posted:

Hi JOHN,

  That is what I did with the pre wired LEDs.  I used the LED and fed it through a brown pipe, the kind that Lionel use to give with its starter set.  I then drill hole through table feed it through add wire, if needed, along with two of the .110 female clips then attach to Fastrack.  Simple easy and they have worked great for five years.

Nice job.

John

@Craftech posted:

Nice.  What was the rating of the toggle switch?

I think it was either 3A or 6A, don't remember which.  Since it was a siding with only one train on it, I wasn't worried.  Those got sold with most of my Fastrack, so I don't have them around to check.

@gunrunnerjohn posted:

I think it was either 3A or 6A, don't remember which.  Since it was a siding with only one train on it, I wasn't worried.  Those got sold with most of my Fastrack, so I don't have them around to check.

Thanks,

John

@Rod Stewart posted:

Here is the wiring diagram and a picture of the finished panel. It's not a fancy panel like grj's, but hey, it gets the job done. Note that there are 6 switches currently wired, with provision for two more.

My power distribution panel looks like Rod's... except, I'm lazier and used On-Off toggles with the led built into the toggle.  They come in a variety of colors.

My main power control looks like this, it handles the four transformers.

I picked up that & the wall plugs as well John... thanks to you!    Mine doesn't have the fancy 'Master' label... although, it should.

The "master" turns off the whole layout, it also turns on/off my "pilot" light to tell me the layout is on.  The other four are my four transformers.

@Dennis-LaRock posted:

My power distribution panel looks like Rod's... except, I'm lazier and used On-Off toggles with the led built into the toggle.  They come in a variety of colors.

I noticed that GRJ used a SPDT toggle on the Fastrack and you are using a SPST.  I know you can use a SPDT as a SPST depending upon how you wire it.  Are we talking about whatever is handy or some other reason.

John

@Craftech posted:

I noticed that GRJ used a SPDT toggle on the Fastrack and you are using a SPST.  I know you can use a SPDT as a SPST depending upon how you wire it.  Are we talking about whatever is handy or some other reason.

John

No reason, I just happened to have a bunch of the SPDT toggles, you'll also note that the extra terminal is not connected.

I use a Wemo plug through apple homekit for master power which is awesome, because 50% of the time it says “no response” 😂. Have a controller like John’s on a fan in the bedroom that works 100% of the time.

I actually had to buy two different brands to get one that was 100%.  The first one was kinda' flaky and didn't always trigger.  This one has been great, and I no longer worry about it not actually turning things on and off.

@Dennis-LaRock posted:

My power distribution panel looks like Rod's... except, I'm lazier and used On-Off toggles with the led built into the toggle.  They come in a variety of colors.

Dennis, I like those illuminated toggles! I assume they are rated for 12vdc? How do they work at 18vac command voltage? Did you use a blocker diode on the common return side?

Rod

I used lighted rockers for siding control and had to disconnect the common return for the leds. If a car or engine spanned the siding and main with two rollers with the switch off, there was a direct short to ground. I couldn't find any more that didn't do that, so I unhooked the ground and the problem disappeared. It also took me a while to figure that one out. Also, like @Rod Stewart says, most lighted switches are for 12 vdc.

@Rod Stewart posted:

Dennis, I like those illuminated toggles! I assume they are rated for 12vdc? How do they work at 18vac command voltage? Did you use a blocker diode on the common return side?

Rod

Yes, on the diode.  Track Power 18vac... Command Works Perfectly.

10x DC 12V 20A Blue LED Light Toggle Rocker Switch Control ON-OFF

$17.65 (now 21.15) with Free Shipping (From New Jersey)

Features:
*Color: Blue
* Switch Actuation Style: Rocker
* Led Color: Blue
* Rating: 20A 12V DC (Working for 9V~12VDC)
* Operating Temperature:-25°C~+85°C
* Electrical Life:10000 Cycles

The body of the switch to the end of the terminal measures 1-1/4".  The switch itself, measures from top of body to top of switch, 1-1/4"  The width of the body is 1-1/8".

The (prototype) Control Panel is even Uglier now!  More Toggles, toggles moved and more holes... but, I think it's there now and at some point I'll whip up a fancy new one (or NOT).