I actually posted this first in the "DCC and Electronics" part of the forum but I'm not getting any responses. Presumably the folks who frequent that area are not dinosaurs like me. An intentional dinosaur, at that. :teeth: I'm going to use manual turnout control on my new layout, and I actually have three questions. 1. I got all ready to buy SPDT slide switches to use in fashioning my manual turnouts--they go under the track and allow me to throw the points at the same time as they route power through my power-routing Peco Electrofrog turnouts. This was because I had read about and seen these used. When I did some more research, though, I found an amazing number of people using DPDT switches for this. Which is better? (And why?) 2. Although all I ever see are schematics (which I don't understand), I THINK I can figure out how to wire an SPDT switch for a turnout. How would I go about wiring a DPDT switch for a turnout? 3. I want to be able to indicate the actual position of the points with two green lights for each turnout on the control panel. Either a track is open (a green light) or it is not (no light). How would I wire this, beyond running two wires from each track back to each light? Is this why some people use a DPDT? If I were using a DPDT would I be able to run wires from it to the light? This seems like a lot of questions, but I am just basically lost, lost, lost. I bought two railroad wiring books. I searched the internet. I did a search on Trainboard, too, and came up empty. (Though at least I learned what switches to buy in terms of amps!) I guess everyone else learns this stuff in high school. :embarassed: Any help would be deeply appreciated.
You may already know a lot more than I have done, but I THINK I know how. I will tell you what I think, and then maybe that will motivate somebody to correct me. I am THINKING of slide switches for yard and industrial spur turnouts near the front of the layout. For use on turnout power routing, the single throw double position connects a middle wire to one or the other of a pair of outer wires. The outer wires are feeds from the north and south rail of the track on the point end of the turnout. The center wire goes to feed the frog. You say you "want to be able to indicate the actual position of the points with two green lights for each turnout on the control panel.... How would I wire this, beyond running two wires from each track back to each light?" I cannot understand what good it would do to run two wires from each track back to a control panel light, unless there was a switch on the turnout itself for the purpose of sending that light signal. As I understand it, a double position/ double throw switch is like having two two-position switches that switch at the same time, built into the same switch. One "side" of the switch can be used to route power to the frog, the same as on a STDP switch discussed earlier. The other "side" of the DPDT switch (my terminology may be all mixed up) is used to power one or the other of the two control panel lights. Power for the panel lights goes to the center wire of that side of the switch, and the other two wires on the switch each go to one of the panel lights. Okay, clear as mud.... Sorry.
Ok Chaya hope this helps: A SPDT will only allow you to power the frog of the turnout because it only has one pole or power connection. A DPDT has two connections that are independent of each other so you can use one to power the frog and one to power you lights on your console panel I hope this cruddy diagram helps Basically if you want to power just the frogs use the SPDT if you want to do both you will probably have to go with the DPDT unless of course you wanted to.... rambles on about electronic circuits you really don't want to know about... :teeth: GOOD LUCK
Sleep Sloth (welcome!) has the basic use of the DPDT switch for power-routing through isolated frogs and position indication covered. It is the method I will be using for my Atlas C55 turnouts using both Blue Point and Tortoise machines. In Chaya's case the Electrofrogs are live through out the turnout - one rail on the diverging route is one polarity and everything else is the other (and vice versa). If you are diverging to a track that has no separate feeder then no insulation is required for inner rail/s off the frog for that route. If the diverging track has it's own feeder, you will need to insulate those inner rail/s off the frog to avoid a short. Using the slide switch without modifications to the turnout - If the diverging track has no feeder but you want to ensure power to the track without relying on the turnout switch point to provide it, you will need to add feeder wires from the DPDT slide switch you plan to use connected to the approach side of the turnout. This provides the best power-routing as it doesn't rely on the turnout's switch rail for powering the diverging track. It also isolates one rail rather than having it the same polarity as the adjacent rail and provides a stopping section on each route in the converging direction. Using a slide switch with modifications to the Electrofrog turnout - Rather than reinventing the wheel, have a look at the following site - http://www.loystoys.com/peco/about-electrofrog.html It covers mods to the Electrofrog for DCC purposes but the same applies if you wish to power the frog using a SPDT switch (or DPDT with position indication), as Sleep Sloth has above.
Oh, God. I am now SOOOOOOOOOOO confused. I will go back to my monkey see, monkey do school of electricity.
That is just how I feel, Fotheringill. How I wish I had fellow model railroaders to "monkey-see" with here in Santa Fe. There seem to be at least one or two--otherwise there would be no supplies at all at the local Hobby Lobby, and there are at least a few rudimentary supplies. Otherwise, people here tend to look at me like I'm an alien when I say I have a train layout. Lately I've been thinking how if a picture is worth a thousand words (and it is!), observing the real thing is worth a thousand pictures. I think I'm beginning to understand things better than I did, though. Please see my amusing attempt at illustration below: So the left top and bottom posts would connect to the throat of the turnout, while the left middle post would connect to one of the frog rails?? And then the right top post would connect to one green lamp while the right bottom post would connect to the other green lamp, and the right middle post would connect to both green lamps? :unsure8ao:
A DPDT switch is two SPDT switches next to each other, thrown by the same toggle. One side is used for the switch, the other side can be used to turn an LED on and off. Since there are two throws (that's the DP double pole part), you can also wire up two LEDs or one Red/Green LED to your panel if you like. Many become confused about frogs, but that's because one brings in too much extraneous stuff into the mix. I think of it as: Dis Side, Dat Side, which side supplies the power? You have to get power for the frog from somewhere, since it's dead out of the box. The power ALWAYS comes from one of the two rails (makes sense), and these two rails are always the ones leading into the switch from the point side. Sooo, you have to connect the frog to either Dis side's rail or Dat side's rail. You could do this with a wire soldered to the frog, touching Dis side or Dat side to get the power. In fact, it's a great way to get a handle on how things work. Once you get tired of moving the wire, you look at a book about relays, and figure out that the wire from the frog is the center pole if a SP switch, and each rail is the outside poles. The toggle moves the wire connection from one rail (pole) to the other. It may sound too simple, but once you get the basic DisDat worked out, everything else is just multiples of this simple gizzmo. This includes indicator lights and indeed entire signaling systems.
One wire would go straight to the LEDs (call it the ground wire, or - on the power pack) and hook to one leg of each LED. That leaves two more wires, one to each of the LEDs. Hook these up to the outer poles of the switch. The + from the power pack goes to the center pole of the switch. Using the DisDat approach, you then have a path from the power pack, through the switch, then to either Dis or Dat LED. Don't forget the resistor!!! The safest place is in the - (ground), since both LEDs use it. * * If you use two LEDs of different types (colors), they may not each like the same resistor, in which case you would put the resistors between the switch and each LED.
I found this website, which shows how to wire up a module that will allow for panel/indicator lights when using various types of turnout mechanisms. One of these weekends I might attempt wiring up the "Deluxe Circuit For 3-Wire Twin-Coils" circuit. Could be quite the project.
I'm actually going to use "Green LED Assemblies" with built-in resistors, for 12V. Very cool. All ready to go with holder and everything. Radio Shack part 276-271. Okay, Tony, I think I understand. Below is a re-drawn diagram, this time with a power pack. Is this what you were saying? (I haven't the faintest idea why Paintbrush smudged it up).
I think the LED common lead, the one connected to both LEDs should go to the - side of your ACC terminal on your powerpack instead of to the frog. Don't forget the LED resistors! Al
Chaya your last drawing is almost correct except you want to take the leads of both lights to your ground on your power pack and not the frog making a complete circuit through the switch. what you really have here is two complete circuits controlled by one switch. You got in before i did YES! You got it!
actually chaya you have the led/panel indicators connected to the wrong ends when the switch is in the up position (as per the drawing) you will be diverging so the upper right should go to the diverging light and the lower right should go to the straight light. have we confused you enough yet? lol
Maybe not him, but surely me. Would you be interested in doing a How To blog here at Trainboard on the topic? Any of you electricity people?
I've made up a few images to explain further what I posted above. 1 - Electrofrog turnouts. These have live frogs. In other words the frog is the same polarity as the closed switch. Also, the open switch is the same polarity as the closed switch. The rails from the frogs through both routes need to be insulated to prevent a short circuit. If the blue rails in the image below were not isolated at either end the + and - will be connected and a short exists. With the below, I have shown the converging rails to the turnout being isolated both ends to create a stopping section. This can be a short as you like and will prevent a train hitting the turnout when it is set against it and shorting the track block. This is not needed if you don't want this protection. The insulated joints at the frog are, though. A DPDT switch will do the power switching and maintain polarity separation. If you require indication of switch position a 3PDT switch is needed, two poles for the power routing, the third for indication. 2. Modified Electrofrog turnout (Also known as DCC-friendly) Here the rails between the switch and frog are cut to isolate the frog. A connection is then made through one pole of the switch from each rail to the frog. Electrofrogs have the wires underneath the frog area open so a solder connection can be made there. This isolates the turnout switch from the frog and prevents any short happening between the switch and stock rail unlike the unmodified Electrofrog (but with the gap provided on Peco's it's rarely been a problem unless you're wheel gauging is way off). The same applies with the above image regarding coming into the turnout in the converging direction against the turnout position and shorting on the frog. The adavantage here is only one pole of the switch is required for power-routing and the second pole can be used for turnout position indication. Note - the Atlas C55 turnouts are like the image below as they have isolated frogs that need to be powered if you require them live. Are the C80's are more like the Peco Insulfrog? 3. A simple indication circuit The indication side is very basic. All you need to supply is a positive (or negative depending on your needs) to the centre of the switch and two wires off the normal and reverse side to your indicator of choice. If using LED's, you can place a single current limiting resistor on the common negative leg after the LED's. By common I mean they are joined at ccommon point between the LED anodes and power supply.
Nope, it's getting clearer all the time! Soon I'll be able to find my way out of a box! :teeth: How about this, Sleep_Sloth? (Man, this diagram just gets fuzzier and fuzzier...)
