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Hey guys,

I've searched and found similar questions, but mostly geared toward Digital control where systems will send constant power to the track.

I'm putting together a layout that will have a half dozen or so power districts running off of each side of a KW transformer.  I'm using all conventional operation, nothing digital at all.

I intend to toggle power to each district via a board (about 12 x 24 inches) that has a map of the layout and one switch for each zone.  I'll send a bus to the base of the board and all switches will be wired to the bus and then send a 20 or 18 ga wire out to the center rail on the layout.

I'm trying to concoct a way for dad to easily see which zones are active at a glance (he's getting older and I'm trying to make it as clear as possible).  I know I can use some basic 6A/125VAC rated toggles that are pretty cheap, but they're not lighted to indicate which toggles are on.  It's easy for met to tell by looking at their physical position, but not so much for dad.  

I figured I could build in an AC 14 or 18V bulb in line with each switch, but then I'm using another quarter or half amp for each bulb stealing some wattage from my transformer.  With 6 or 8 zones, plus the lights in the cars (many are LED now but still have lots of PW cars with incandescent lamps) I'd like to leave as much of the KW output as possible going to the track.  We already max out the KW running some of our PW stuff, so trying to keep away.

I figured I could use LED's as separate indicator lamps, but I have no idea how to wire them in series without killing half of my power (don't they basically act as half-wave bridges if they're in series?) Or could I put an LED in parallel with the switch output?  Would that even work?  Also seems like lots of extra work drilling holes at the panel and wiring stuff.  OR use a DPST switch and have the leds all on a separately-powered circuit from a wall wart or something? Then I ened to screw with resistors, etc...

I've seen illuminated switches that I Can install in a round hole (trying to avoid rectangular holes since I want to build this panel myself with a simple drill) but from what I gather the LED versions all have leds in series with the switch (bad for me) and the incandescent ones are all rated for 125VAC and I'm guessing that my paltry 16VAC won't light them, making the lighted feature useless.

Any suggestions for the easiest way to install a lighted toggle that can handle the KW output?


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I get overwhelmed looking at options for things like relays. Are standard automotive relays (with the 12v could and 12V 30amp rating on the triggered circuit) ok to use? They're really cheap on Amazon, and some have built in fuse holders that I could put a10 amp fuse in for each of my districts (like these:


But I don't know if I need a relay that is rated for AC (20V). I only need 10 amp rating, but there's so many 12VDCv relays rated for 40 amps I gotta think that excess capacity is Ok for my 20Vac 10 amps. Or is it?


You don't need automotive relays. I was thinking more like these relay modules:

These are rated at 10 amps and come in a variety of boards. You can get them with 1/2/4/8 relays per module. They have them on Amazon under the brand name HiLetGo. I like the ones with the Hi-Low trigger jumpers (s1, s2, ... in the picture shown above). I usually get mine from eBay.

You would want the 12 volt versions.

I went through some illuminated switches on eBay and didn't find any that have lights for both on and off conditions. The ones I saw only light up when the switch is turned on.

Fuses are a different issue. They can be added inline later on.

I used automotive switches with the 18 vac train voltage  which are lighted and need no additional circuitry. The RMS voltage on the LEDs is around 12 vdc, just right being half wave thru the LED. Here's a diagram.

CaltermSwitchWiring [2019_01_25 19_35_47 UTC)

You can hook all the "Earth" connections together and use one diode which protects the LEDs from the reverse half cycle of the AC.

Here's the switch package...

CaltermSwitch [2019_01_25 19_35_47 UTC)


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  • CaltermSwitchWiring (2019_01_25 19_35_47 UTC)
  • CaltermSwitch (2019_01_25 19_35_47 UTC)


Above photo hijacked from this OGR thread may shed some light on the method Leo suggests.

All the control-panel wiring would be 12V DC which could come from a wall-wart AC-to-DC adapter.  These adapters are less than $5 shipped.  Another photo from linked thread:


LED-illuminated automotive toggle/rocker switches are widely available but are meant to switch 12V DC.  Should be able to get them for about $1 each shipped.   Note that while you can solder wires to the terminals, you might want to get a bag of crimped spade press-on connectors.  Also, the hole size for these is something like 1/2" (or more) so measure-twice, drill-once (!).  That is, if cutting an acrylic panel you might need a special drill bit.


Then you use 12V relays to switch the actual train track AC.  As Leo says 10A relays are readily available in 1,2,4,8 and even 16 channel modules... maybe $2-3 per relay.  Following photo hijacked from this OGR thread showing relative size of automotive switch, 1 and 4 channel relay module, and O-gauge track.


As discussed here and there, one benefit of using 12V lighted switches and 12V relays is you can typically reduce the amount of heavy-duty, thick wiring.  By this I mean all the control panel wiring and the wiring from the panel to the relays carry relatively low-currents so you can use thinner wires which are easier to work with behind a crowded control panel and to construct wiring bundles or harnesses.  If you sketch out a "to-scale" drawing of your layout showing the required wiring runs or 12V control signals and AC track voltage you might see using, say, two 2-channel relay modules and one 4-channel relay module can make for "neater" wiring than a single 8-channel module.

If this approach is something you'd like to pursue, we can identify specific Amazon listings if that is your preferred supplier.




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Last edited by stan2004

@stan2004: That's exactly what I'm looking for!  Thanks so much!  I didn't realize they relays could be purchased pre-installed in the modules with the screw terminals.  I think that's definitely how I'm going to go about it.

I've got enough wall warts and transformers that I can send 12V to the switches no problem. I was worried about going the relay route because I didn't feel like I was ready to solder everything up, but the pre-installed modules look good to me.  Are the relays replaceable on the modules if they go bad?  

If you've got links, I'll use 'em, otherwise I'll start looking on my own for the above.  Thanks a bunch!


Other hobbyists have contributed helpful suggestions, and you may already be moving forward with those tips.

I considered lighted toggle switches for identification on four stub sidings on my L-shaped layout, but installed a different "solution."  I placed four unlighted toggle switches in a project box at the control panel and activated the sidings with them. Then I installed a lighted Lionel bumper at the end of each siding. When a toggle switch was ON, the bumper light at the stub siding was also ON and served as an indicator.  Readily noticeable for me to see as an 81 year old -- and probably useful to your dad!

Mike Mottler    LCCA 12394



auto switches and relays

I've never figured out the OGR restrictions on including direct links to non-OGR sponsors, but "12V LED car switch" is a good search for the switches.  Note the LED-color selection options.  On the right there's even a vendor with pre-wired switches though not clear if the potentially too-short supplied wire length just means more work!  BTW, upon closer examination I see the hole size for this particular style (there are other styles of course) is 20.7mm or a 13/16" drill bit which one might call larger than typical.

As Leo suggested search "Hiletgo 12V relay module" and you should get above with the attractive price of less than $2 per relay.

Heck, if you're going for, say, 8 channels it seems that 8 switches and 8 relays may not even break the $25 threshold to get Free shipping on Amazon. LOL. 

And to your question, no, the relays on these module are soldered in place.  They are NOT socketed.  If you had to replace one, the "loose" relays are widely available for maybe $1 a piece but considering the cost of the module(s) I can't imagine anyone firing up a soldering iron and such!  BTW, these modules have tiny LEDs for each relay that light up when a relay is thrown.  While the module might be hidden under your layout, these LEDs can be handy when troubleshooting initial installation to confirm the control signal is making it to the relay module.  And of course these are generic relays so you'll hear the tell-tale 'click' on and off.

These modules have been used by a lot of guys on OGR so assistance is readily available...


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  • auto switches and relays
Last edited by stan2004

And since I am fixated on the 13/16" mounting hole for some LED switches, yet another option for the lighted switch function is to separate the switch and LED.  You can buy pre-wired mini toggle switches which typically require mounting hole of 1/4" which I figure might be the most common drill bit size in the world?!  Likewise you can buy pre-wired 12V DC LEDs so, to your earlier point, you don't have to fuss with resistors.  There are a wide variety of mounting bezels for LEDs to clean up the presentation if need be.  

12v pre wired led

So the idea is to replace the relatively large automotive LED switch with a generic unlit toggle switch and a separate 12V LED.  Same 12V relays are used.  This requires 2 "smaller" mounting holes instead of 1 "larger" hole but may provide more flexibility in the control panel layout ... and still not qualify for Amazon $25 free shipping. 


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  • 12v pre wired led

Went ahead and ordered a 4-relay module and a set of 12V green lighted switches as you recommended above.  The HiLetGo ones weren't available in the 12V 4 channel module, but it appears that may of these modules are the same thing sold by different distributors.  The one I got was a "Vogurtime" brand.

@Mike H Mottler: Good suggestion, and I'll be using some of the classic Lionel lighted bumpers at the ends of my yard for an additional indication, but that won't work for the power zones that are part of my loops.  I'll probably add some basic 14V lamps near the power zones on the layout to indicate that the relay actually flipped and is feeding power.

Great suggestions, guys.  Will let you know how it pans out!



Another way to show when a track section is powered below.

I have three sections of track that are isolated with slide switches on the control panel that has a layout diagram that has the slide switches on their white line indicated section that shows black for the OFF and white for ON.

Train Complete 1-17-2015 152

On the layout I installed two Plasticville two track signal bridges over the sections and the signal light on the bridge is wired to the center rail to light when power is on that section and off if the power is off or when the section switch is set to Off.  I installed grain of wheat 12v bulbs behind the plastic colored lights on the bridge.

Picture of Plastiville two track signal bridge off the internet


Kind of make you wonder if the company name is really Yogurtime - as in it's time to get Yogurt.  That is, in the product photo their labeling for what should be "high" is off a bit depending on where you look.  Obviously this has no effect on functionality but it is arguably amusing! 


In any case, those 4 yellow push-on jumper should be installed exactly as shown in photo.  That is, this will be configured as "high" level triggering since when you flip the LED-switch to the "on" position it will send a "high" 12V DC signal to the relay module.  You'd move the yellow push-on jumpers to the "low" position if you send Ground or Common to the input triggers to activate the respective relay.


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  • vogurtime

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