Ok I have my kato turnouts all hooked up to toggle switches and are work great. Now I have hooked up red and green leds with resistors and I can get them to turn on when the toggle is thrown for the switch . My question is how do I get the leds to stay on when the turnout is thrown. Basically I know I need to hok them up to the turnout but I am looking for help on this. Does anyone have a suggestion. I took apart on of the switches to check the mechanics on it and I think I can solder the wires of the led's to the brass plates inside the switch but not sure if that will work??????? Looking for help or suggestions
This is where we need our electrical engineers to sound off. I know it takes electronics to make this work but I have no idea where to start. You'd be helping both Dave and I out, with a answer.
Kato Switches use a pulse to power the switch motor. Other than the DCC starionary decoders (Switch-kat from NCE) - there is no simple method to keep either LED on.
Hi Jim, What do you mean by pulse to power. Are you saying that the switch just sends a short burst of electricity to the switch to acivate the magnet coil to move the switch. So what about hooking to the rails those have constant power dont they? I have #4 Kato which are power routing how about those?
Actually he might be able to use cheap relays that are thrown by the same button as the switch machine. RadioShack sells a little one for about $6 that'd probably do the trick. Let me flowchart the process and see if I can come up with a workable schematic for the circuit.
That would be great if you could. Let me know a comtrol panel with red and green lights would look awesome. Hopefuul you can. Thanks....Dave
OK, took a little research to find what I needed but here you go. The key to making all of this work is a lesser-known relay called a Dual-Coil Latching Relay. This little guy works pretty much the same as your switch machine, changing the output "direction", if you will, when you trigger one side or the other of the relay coils. Traditional relays won't work because there is only one actuating coil, which means your panel lights can easily get out of sync. This will remember your switch position (assuming you don't manually throw it!) even when you remove power from the circuit. Now this also assumes that you use 12V DC (not AC) power for your switch machine. Also, this assumes that your LED's are properly configured with resistors or whatever is necessary to make them compatible with 12V DC power (check and DOUBLE CHECK!). Here's some at a good price: Lot of 10 FRT3-SL2 Dual-Coil Latching DPDT relays And another: Omron G2RK-2-DC12 at Mouser Electronics You could also use one with 5V DC coils, but again, you'll need to add resistors to match the voltage. And f the power feed needs to be different to the switch machine, you could also substitute DPST momentary contact pushbutton switches. Hope this helps and let me know if you have any questions. -Matt
Great circuit, but there is a much easier way to do this. Over on the Yahoo N Scale Group Ray Stillwell (the guy who invented diode drop constant lighting) gives out a circuit that does this very well. I can't give it out, Ray wants to do that, but I can tell you it is the best way to control switches I've used in the 50+ years I've been a model rail. Ray published a short artive on this in Mainline Modeler before it went belly up, but has much more info in the pdf he gives away. I'm using Bi-color LEDs for indicators and this simple circuit drives both the switches and the LEDS. With the cheap toggle switches available on the bay, the LEDs and the components, I've got less than two fifty in it per control. I've got 22 of these hooked up over the past year and am gathering components for the staging yard I'm about to add. Please give it a look, you'll be glad you did.
I knew someone else must have done this before! Excellent!! This is the purely-analog solution and, if you get the relays in bulk, can be pretty cheap ($2-$4 per turnout). I'll check out Ray's solution next. THANKS!:tb-biggrin:
Thank you for the info. I will try to get to that site and see if I can get it. Do you know his on screen name or don't I need that. Thanks Dave
That will work for the Atlas turnouts, not for the Kato. Kato is a two wire turnout motor. There is only a single solenoid driving the switch points. The Kato controler reverses polarity as you throw the switch handle and then gives a momentary pulse to throw the switch. The same solenoid handles both directions by changing polarity. If you give them more than a pulse of power, you will burn up the motor. Applying constant voltage to the turnout will fry it. They need a momentary pulse. The Kato turnout control does that by design. If you want to use momentary pushbuttons, you should use a capacitive discharge system to power the turnouts to keep from burning them up.
Hi Carolinla and PW. I was not able to locate the yahoo n scale train forum. PW I hope you were so you can pss the info on to me. And to Carolina thanks for the info maybe if you can send Ray a message and then he can send the info to me. So you have 22 switches must be a big layout. Maybe you can draw me a diagram of how you have it set up then take an image of it and post it. Anyways I am glad people on here are trying to help its great. Thanks. Dave
CD units are not recommended or either Kato or Tomix switches. They operate by attracting a magnet not an iron slug. They will operate using a AA battery, so, they don't need that huge burst of power need for those Peco, Atlas or other solenoid based system. USING PUSH BUTTONS WILL NOT WORK AS YOU NEED TO REVERSE THE CURRENT TO CHANGE THE POLARITY OF THE COILS THAT ATTRACT THE MAGNET. Here are the designs that Mike Fifer and I came up with to make our own Kato/Tomix Switch Controllers..The simplest uses a momentary double throw, double pole switch. The other two are standard switches. the last one uses a Triple Throw TRIPLE Pole to have enough wiring for the constant on LEDs. Each set increases in complexity. The versions with push buttons can be built two ways. One button per switch - You must throw the toggle and push the button to activate the turnout. One button per control board - You throw the toggle switches to set up your route, then push the button to activate the turnout(s).
Chicago, thanks for the diagram. I am assuming that 3rd drawing is a triple pole double throw. I have the switches set up already like the first diagram with the leds coming out of the middle poles and hooked the pos of one led with the neg of the other led connected together and they do work when the toggle is activated but don't stay lit. I am assuming the 3rd diagram will keep the led lights on when after the kato switch is activated. One question what is the push button for. Is that so that there is no constant power to the switch to keep it from burning up or ie melting the plastic inside. I will try this and let you know how it works Thanks Dave
You are correct the push button is to provide momentary power. The toggle switches in the second two circuits are not momentary, so they will not self center and cut power. That is also how the second and third circuits indicate turnout position. The third with the LEDs can be seen from across the room. They can also be hooked up to track signals. The other ways I've seen this done require complicated circuits with ever rarer circuits and relays. You could build design three with a three leg bi-color LED or two separate LEDs.
Two questions: Are you using DCC? and if not, is it enough for the LED's to be lit when there is power to the track(engine approaching turnout, LED lit, engine stopped, LED not lit). If the answer to either of these questions is yes, then I have a fairly simple circuit that is wired directly to the turnout. Here is the DCC only version: and here is the DC or DCC version:
Nice and clean - minimal parts and wiring. Because of the DP Switch - this circuit "remembers" the switch machines last position and lights the appropriate color of LED. I built one almost identical and here are a couple of hints. Using bi-color LEDs for indicators can be a problem. Most bi-color LEDs are common cathode, this circuit is wired for common anode. I did find one from LEDtronixs Part Number L200TWRG4B-3A (5mm part) - they were about 25 cents each. I also used an 820 ohm resistor for bias.
