The signals on my layout are wired up as turnout position indicators - mostly on the frog end, and they show which path is selected. To do this, I use either a separate relay or a mechanical attachment to the switch machine. These are effectively Single-Pole, Double-Throw toggles.
I'm using dual-color red/green LEDs for my signals. Are yours dual-color LEDs like these, or separate bulbs for each color?
It takes an iron man to play with a toy iron horse.
-Dan
Builder of Bowser steam! Railimages Site
I, and my prototype, use dwarfs as turnout direction indicators, so the 2 dwarfs controlling movement into the frog end of a turnout always have opposite indications depending on which way the points are thrown. Likewise, the dwarf at the point end will display more restrictive for the, "Reverse," point setting, and less restrictive for the, "Normal," point setting. All three dwarfs for a single turnout, and the turnout motor or ground throw, would operate together.
In model form, this can be done with one set of SPDT contacts on a switch machine, a separate SPDT switch or a SPDT switch mechanically connected to the ground throw. The disadvantage of a separate switch (not connected to the ground throw) is that there are two separate controls and one or the other could be overlooked - especially by a novice operator.
Personally, I use toggle switches at the fascia line, mechanically linked to the points, to control manually thrown turnouts and all associated electricals. Turnouts controlled from different places are fitted with 2-coil switch machines and signal circuits are routed through the switch machine contacts.
Chuck (modeling Central Japan in September, 1964 - with dwarfs within yard limits)
outdoorsfellar wrote:... that's why I want them to be wired independantly from the track. I just wanna make sure I don't end up frying anything if I wire them the way I'm thinking I would.
Wire the two LEDs in series Anode to cathode. The LEDs will have one lead in common. Use a split power supply. Ground goes to the two single leads. + and - to each end of the SPST switch. Center of switch through 1k nominal resistor to common LED connection.
Better solution is to use two resistors - one in series with each single LED lead. This will allow you to use different resistance values to adjust for similar brightness.
Adaptable to bi-color LEDs too.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
Thanks again. I just found this diagram that shows what I want to do for the most part. It shows using a DPDT toggle, so I dunno if it has to be exaclty like that. Let's pretend this has nothing to do with model railroading ... just an attempt to light up a red or green LED using a toggle to select which color I choose ....
In the end, it will be a simulation of block detection which would be less expensive & less of a hassle of wiring up normal signal controls. With that said, I'm looking for reasurrance I suppose that this would work for what I'm wanting to accomplish. For the signals I'll be using, two resistors come with each signal. Any suggestions on this approach ?
2 LEDs (red and green), SPST, 9V power supply, 1K resistor. You may have to fool around with polarity to get the LEDs to light but it will work. Forgive the drawing, it's late.
UpNorth wrote:
Thanks for the help, I really appreciate it. I am curious as to how we get a 9 volt supply. Also, why isn't the long leg of the red connected to the short leg of the green ? Is that because it's due to being a 9 v hook up ?
outdoorsfellar wrote:Thanks again. I just found this diagram that shows what I want to do for the most part. It shows using a DPDT toggle, so I dunno if it has to be exaclty like that. Let's pretend this has nothing to do with model railroading ... just an attempt to light up a red or green LED using a toggle to select which color I choose ....In the end, it will be a simulation of block detection which would be less expensive & less of a hassle of wiring up normal signal controls. With that said, I'm looking for reasurrance I suppose that this would work for what I'm wanting to accomplish. For the signals I'll be using, two resistors come with each signal. Any suggestions on this approach ?
This is a prety good diagram of how to do it. Now to let this tshow which way the TO is thrown (what I was trying to explain before).
When you set the TO to the diverging route, you'll throw the switch below your benchwork, and the lichts will change...
This is what had in mind... The Blue line is the pushrod to your fascia panel, and the red line is the turnout throwbar.
All you require is to turn on a LED when you toggle the SPST switch. You don't really need all all the fancy criss-cross wiring to invert polarity. That is good if you are running a dual color LED . From what I see, you're not, just the red and the green.
Use a 9V (wal-wart) power supply if you're only doing this for a few LED. More LED's, more amps.
I forget the long lead, short lead thing. Just try it, you can't blow the LED as long as you put the resistor in the circuit.
Ok, one more question. Today I made a mock up using the diagram below. The only difference was that I used a 12v DC powerpack for power & I used a SPDT toggle that I already had. I want the on-off-on capability anyway. The lights worked like a charm. I stopped at Radio Shack yesterday & though they had sub miniature red bulbs, I had to buy a larger green bulb. Anyway, just as I somewhat expected, the resister became hot while having either bulb on using the 12v. I tried a 9v battery for the hell of it & that worked too, but the resister did not get hot. I figured it got hot the other way was due to more voltage for that one set of bulbs. I plan on having quite a few more signals hooked up once I implement this, & I'm thinking that will disperse the heat when I do that & things will be ok. Is my thinking correct ?