Resistors have no polarity. So they can be wired in either direction.
Correct, it's that easy. It doesn't even matter which leg of the LED the resistor is on, they're simply in series.
Thank you so much guys for your help. I’m looking forward to seeing this in action.
Hi Gunrunnerjohn, I’ve started wiring my switches according to the previous directions you gave me. But I’m having problems. Accessory power is working fine. But the wiring for the remote momentary switch is giving me fits. On first try, I soldered a resistor to one leg of the LED and the other end to the yellow wire. I connected the green and red wires to the outer posts of the SPDT switch, and wired the black wire and the other leg of the LED to the center post of the SPDT. Nothing worked. No lit LED, no movement of the frog, nothing. And the lantern on the turnout didn’t light up either. I checked continuity of the momentary switch and found that power goes to the center post and the outer posts get the thru and turn wires. So then I tried switching the red wire to the center post and the yellow wire to an outer post, keeping the LED and resistor on the center post, and the other leg of the LED to the black wire. Still nothing. But when I touched the resistor hooked to the red wire on the center rail of the turnout, the LED came on green, but I was not able to move the frog via the momentary switch. Also, a funny smell emanated from the momentary switch if I held the wire on the center rail for more than 30 seconds. I took the metal plate off the bottom of the turnout to see if I could find a continuity problem there with a test meter, but it’s too complicated for my brain. But I did find there was continuity between the Aux in and the remote red wire. That’s why I put the red wire on the center post of the momentary switch. Any ideas on what I’m doing wrong and how to correct it? It just seems like power is not getting across from the transformer to the remote. Your expertise (or anyone else’s) would be much appreciated. Thanks.
If it's wired just like Chuck's diagram, I'm at a loss. You ARE using a momentary center off toggle, right? You need to have the center off position.
Here's chuck's diagram of the Fastrack switch controller.
Yes, I am using momentary switches with center off. How many LEDs are being used in the diagram? I’m only using one green/red LED per switch, thinking the it will be green on thru and red on turn. The diagram looks like there are four LEDs and four resistors all connected to the yellow wire. I’m not an electrical genius, so could you provide a little explanation of the diagram in layman’s terms for me. Sorry to be a pain, but I’m just trying to get thru the learning curve. Thanks!
There are two LED's for each direction in that diagram, you can simply omit one for each direction. Just leave out the components outlined in red.
SW1 and SW2 are just the two sides of the ON-OFF-ON momentary toggle.
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Ok. That makes more sense. So, what wire gets attached to the center post of the switch? And if I’m using one bi-colored LED (green/red) do I need a resistor on both legs? Does the anode leg get attached to the yellow wire and the cathode leg to the black wire? I’m gonna get this thru my thick skull somehow! 🥴
Center post? There are four terminals under the switch, all of this gets connected to those!
Preacherman78 means the pole on the momentary switch. Black
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Thanks for your replies. So if I’m reading this right, the red and green wires attach to the outer posts of the momentary switch, the black wire attaches to the center post of the momentary switch, and the yellow wire only attaches to the bi-color LED with a resistor. I’m assuming the resistor goes on the anode (long) leg of the LED and then to the yellow wire, and the chathode (short) leg gets attached to the center post with the black wire. With or without a resistor? Is that correct? Thanks for your patience in walking me thru this.
Bi-color LED's don't have an anode and cathode like you'd expect, as there are two LED chips internally facing opposite directions. For bi-polar 2-wire red/green, usually the long lead positive gives you red and the short lead positive gives you green. Just temporarily connect it, if it's wrong, swap the leads.
Do both LED leads get attached to the yellow wire then? And only one resistor?
So ... I finally got this setup to work. But only on track power. If I take out the jumper and connect to aux in and aux gnd under the switch, it does nothing. The lantern on the switch doesn’t light up, the momentary toggle switch doesn’t work, and the LED doesn’t light up. And when I try to apply track power to the rest of the layout, the voltmeter on the MTH Z-4000 reads 1.6 volts and starts to buzz if I move the lever forward. And the voltage will not increase when I move the lever. But on track power it all works perfectly. What am I doing wrong?
Your aux wires are interchanged. Power and com...
Is that in the switch itself? If so, can I just reverse my wires?
Maybe I’m wrong, doesn’t explain why you get no lights before you apply track power. Where’s the aux power coming from?
Aux power is off the constant 14V output of the MTH Z-4000 transformer. I have that wired to a 12 position distribution block. From there is goes to the switch. To differentiate from my track power drops, I’m using orange (+) and purple (-) wire.
I’m not familiar with the Z-4000. Are the connections for the fixed and variable voltage well marked as to the U terminals which you would want to connect to the outside rails and the aux gnd? And the A terminals which will go to the center rail and the aux in? One can assume that the transformer has variable voltage with the common connection to the U terminal and the fixed voltage common to the same U point inside the transformer.
Actually I don’t think you need aux gnd wiring for FasTrack switches since the current is so small, having a return path for the power in is not significant. I think the aux gnd is the same connection as the outside rails on the switch. But that does point out that it’s imperative that the power to aux in comes from the A terminal of the transformer.
The connections are clearly marked on the back of the transformer. The commons all have black screw connectors and the hots all have red screw connectors. On the back of the Z-4000 there are four outputs, not unlike the Lionel ZW transformer. The two outer sets are variable voltage run by the levers. The inner two sets are 14V and 10V constant sources. As for needing aux wiring, I think you’re right. I hooked up my MTH DCS Explorer and it provides constant 18V to the track. The engine is run via an app on my iPhone. So I think I can just replace the black Lionel remote with the setup we’ve been discussing here and everything should work fine. With the app, I can stop and start the engine and power is maintained to the track no matter what the engine is doing.
Wasn't there just a thread going on some FT turnouts having lugs wired wrong from the factory? (old threads too)
Adriatic posted:Wasn't there just a thread going on some FT turnouts having lugs wired wrong from the factory? (old threads too)
Yes, my brand new 072 Wye switch had that issue and I had to fix it.
I don't understand why CJACK on 1/13/2019 needs diodes and resistors for LED's while GunrunnerJohn just needs a resistor. Is it because GunrunnerJohn is using a bi-color 2-pin LED?
I used 2-pin bi-color LEDs on mine and put a resistor on one leg connected to the yellow wire from the switch and then the other leg to ground on the layout. It works great.
michaelblock posted:I don't understand why CJACK on 1/13/2019 needs diodes and resistors for LED's while GunrunnerJohn just needs a resistor. Is it because GunrunnerJohn is using a bi-color 2-pin LED?
I posted a schematic of what Lionel uses in their controllers. And yes, if you use a bi-color 2 pin LED, you just need a resistor to limit the current...you do not need diodes to steer the current to the proper color LED.
cjack posted:michaelblock posted:I don't understand why CJACK on 1/13/2019 needs diodes and resistors for LED's while GunrunnerJohn just needs a resistor. Is it because GunrunnerJohn is using a bi-color 2-pin LED?
I posted a schematic of what Lionel uses in their controllers. And yes, if you use a bi-color 2 pin LED, you just need a resistor to limit the current...you do not need diodes to steer the current to the proper color LED.
Like cjack says, he simply posted what Lionel does in their controller.
The 2-terminal bi-color LED is simply a packaging option that does not suit all applications. Sometimes you want 2 separate points of light. Consider a red-green color-blind individual who would see only an illuminated indicator irrespective if red or green were on!
In other words Lionel could have wired the 2 LEDs of their FT controller like a bi-color LED but using separate LEDs so there are 2 points of light. Then they could have used just 1 resistor and eliminated the 2 diodes.
If you dig deeper, there are reasons to use the Lionel approach but devolves into arcane technical mumbo jumbo. Plus, these are penny (or less) components...so the cost penalty was a few cents.
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These comments answer my question. Thank you.
