I have a control panel with a number of DPDT switches used to control Tortoises.
Each DPDT has two wires connected to a DC power pack on the outer terminals, and two wires from the center terminals are connected to the Tortoise. The circuit is completed by crisscrossing wires on the four outer terminals.
I also have a 2 leg bi-polar LED connected to the two center terminals on the DPDT to show the route of the turnout controlled by the Tortoise, green if straight route, red if divergent route.
That all works fine. But, now, I am changing the control panel.
Without going into detail, I am replacing the DPDT toggle switches with momentary push buttons, normally open. These push buttons will be connected to an NCE Mini Panel. So, two wires connecting the push button to the Mini Panel.
Now, I still want to use LEDs on the control panel to indicate turnout routing. So, I will connect two wires from the Tortoise to the LED on the control panel and one more wire from the Tortoise to the DC power pack. But, now I have only one side to the circuit completed. I assume that I need a 3 leg LED so I can complete the circuit with a second wire from the DC power pack.
Is there any way to still use 2 leg LEDs on the control panel?
Rich
Alton Junction
Rich, This month's Model Railroad Hobbyist online mag. has an article about using momentary push buttons with Torti
regards, Peter
Well, you have chosen to use push buttons. That kinda limits things. LION uses SPDT switches. If you want lights to stay on, you would need to have to Tortose contacts report back to you their status.
Another posibility is to use latching relays (Check Digi-Key) or use two relays. I use a 4PDT relay when the reverse route is selected, and use one of the poles of the relay to latch the relay. Pressing the other button energises a smaller second relay which will release the latch.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
richhotrainWithout going into detail, I am replacing the DPDT toggle switches with momentary push buttons, normally open. These push buttons will be connected to an NCE Mini Panel. So, two wires connecting the push button to the Mini Panel.
how do you intend to reverse the polarity on the Tortoise switch motors with push buttons?
richhotrainNow, I still want to use LEDs on the control panel to indicate turnout routing. So, I will connect two wires from the Tortoise to the LED on the control panel and one more wire from the Tortoise to the DC power pack. But, now I have only one side to the circuit completed. I assume that I need a 3 leg LED so I can complete the circuit with a second wire from the DC power pack. Is there any way to still use 2 leg LEDs on the control panel?
i think your current wiring is similar to the diagram below, the tortoise motor is driven thru the LEDs
but if you're not going to supply constant power to the Tortoise motor, couldn't you use one of the Tortoise SPDT switch to drive LEDs. wire the common (4) to a supply thru a resistor and each side of the switch (2&3) to an LED.
greg - Philadelphia & Reading / Reading
OK, the pushbuttons are driving the minipanel. Now what is the minipanel driving to operate the Tortoises? Which stationary decoder are you using?
NCE Switch-Its are cheap but putting the LED in series will probably drop too much voltage - they run slow as is. Not sure about the Switch-8, never tried one of those. Othr stationary decoders may put out closer to the full 12 volts, so dropping through the LED results in just the right voltage to make the Tortoise work fast enough while keeping the noise down.
It's an awful lot of extra wiring, since typically the stationary decoder will be by the Tortoise, so that's another 2 wires to run all the way back to the control panel - basically, saving nothing by going with the mini panel.
To use a 2-leg bicolor LED with just one SPDT contact, you need a bipolar power supply, with a +12, -12, and common. Or any voltage, really - the voltage determines how big a resistor you will need. The common goes to one leg of the LED, the other leg of the LED goes to pin 4 or 5 on the Tortoise. The +12 goes to 2 and -12 to 3 (or 6 and 7), flip around as required for the proper indication.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
This has been an evolving project for some time now.
I have a 10-track passenger station controlled by 9 turnouts, the lead turnout into the station branching off 8 more turnouts to feed the 10 tracks.
Originally, I used manual ground throws (Caboose Industries Hi-Level Switch Stands) to operate the turnouts. But that grew old fast, particularly because the passenger station complex sits on a 6' x 12' peninsula at one end of my layout, and I have to run around the peninsula to set the turnouts.
So, I automated the turnouts by installing Tortoises and wiring the Tortoises to DPDT switches on a control panel. The 2-leg bi-polar LEDs connect to the middle contacts on the DPDT to provide visual indication of routing. That works fine, but it still requires me to set the correct routes by flipping a series of toggle switches. It is further complicated by the fact that the lead turnout is a RH turnout, not a wye, and six of the tracks are controlled by two 3-way turnouts for space saving reasons. Not terribly complicated but, hey, I am lazy and looking for something easier to operate.
So, I have decided to fully automate the routing. I am about to install a Switch-8, one Switch-It, and a Mini Panel. The pushbuttons will be wired to the Mini Panel which will reside behind the control panel. The Mini Panel communicates with the stationary decoders via the track bus.
Because the push buttons are momentary, I can not think of a way to retain the 2-leg bi-polar LEDs on the control panel. Since I already have the wiring in place from the control panel to the Tortoises, once the stationary decoders and Mini Panel are installed, I can simply swap the two wires to each Tortoise to two legs of a 3 leg bi-polar LED by moving the wires from their power positions on the Tortoise to the switching positions on the Tortoise. A nearby DC power pack can complete the circuiit with one wire to the Tortoise and one wire to the center leg of the bi-polar LED. I know that will work, but I was curious if there was a way to salvage the 2-leg LEDs.
http://www.youtube.com/watch?v=1v5H84xmlpM Here's the video for push buttons. Jim
richhotrainI am about to install a Switch-8, one Switch-It, and a Mini Panel. The pushbuttons will be wired to the Mini Panel which will reside behind the control panel.
in the switch-8 Accessory decoder manual doesn't the diagram on page 4 show you how to wire up the LEDs similar to the way you currently do?
gregc richhotrain I am about to install a Switch-8, one Switch-It, and a Mini Panel. The pushbuttons will be wired to the Mini Panel which will reside behind the control panel. in the switch-8 Accessory decoder manual doesn't the diagram on page 4 show you how to wire up the LEDs similar to the way you currently do?
richhotrain I am about to install a Switch-8, one Switch-It, and a Mini Panel. The pushbuttons will be wired to the Mini Panel which will reside behind the control panel.
My problem is that the control panel is about 6 to 8 feet from these devices, and I don't have a continuous, uninterrupted source of DC power nearby. So, I am forced to string wiring from the Tortoises to the control panel where the LEDs will be located.
richhotrainMy problem is that the control panel is about 6 to 8 feet from these devices, and I don't have a continuous, uninterrupted source of DC power nearby. So, I am forced to string wiring from the Tortoises to the control panel where the LEDs will be located.
So you like a way that a pair of wires for each Tortoise can drive a pair of LEDs to indicate the Tortise position?
gregc richhotrain My problem is that the control panel is about 6 to 8 feet from these devices, and I don't have a continuous, uninterrupted source of DC power nearby. So, I am forced to string wiring from the Tortoises to the control panel where the LEDs will be located. So you like a way that a pair of wires for each Tortoise can drive a pair of LEDs to indicate the Tortise position?
richhotrain My problem is that the control panel is about 6 to 8 feet from these devices, and I don't have a continuous, uninterrupted source of DC power nearby. So, I am forced to string wiring from the Tortoises to the control panel where the LEDs will be located.
richhotrain gregc richhotrain I am about to install a Switch-8, one Switch-It, and a Mini Panel. The pushbuttons will be wired to the Mini Panel which will reside behind the control panel. in the switch-8 Accessory decoder manual doesn't the diagram on page 4 show you how to wire up the LEDs similar to the way you currently do? The diagram shown in the manual shows the LED connected between the Tortoise and the stationary decoder (Switch-8, Switch-It) and those two devices are very close to one another. My problem is that the control panel is about 6 to 8 feet from these devices, and I don't have a continuous, uninterrupted source of DC power nearby. So, I am forced to string wiring from the Tortoises to the control panel where the LEDs will be located. Rich
The diagram shown in the manual shows the LED connected between the Tortoise and the stationary decoder (Switch-8, Switch-It) and those two devices are very close to one another.
Unless I'm missing something, I don't see why you can't use the diagram in the Switch-8 manual. You have the bipolar LED at the control panel(the manual shows two separate LED's in parallel, but that is what the bipolar package is). You have two wires running from each Tortoise to the control panel. You'll have two wires from the Switch-8 to each tortoise. Use the two wires going to the control panel two splice the LED into one of the wires going from the Switch-8 to the Tortoise. It doesn't matter that the control panel is 6-8 feet away.
2 leg or 3 leg LEDs, you're going to have to run wires from the Tortoise back to the panel. My suggestion witht eh bipolar power supply would mean only 1 wire from each Tortoise back - the + and - power supply leads would run from Tortoise to Tortoise like a bus, and you'd need to run the common from the power supply to the panel. Then one wire from each LED to the switch contact terminal of the Tortois (4 or 5, doesn;t matter, you can use either set of contacts, saving the other for the frogs).
to re-use your 2-terminal bi-color LED, you would need 2 wires where the voltage on those wires can be reversed. You could wire from the switch-8 through your 2-terminal bi-color LED and back to the Tortoise. Apparently this is not desirable
You can use a 3-terminal bi-color LED, single-ended DC supply and a Tortoise SPDT. The DC (+) supply can be wired to the common SPDT terminal (4). The other SPDT terminals (3&2) are wired to separate LEDs. The common LED terminal is wired thru a resistor to the DC (-) supply. 3 wires are needed between the panel and each Tortoise.
greg, Randy, and CSX Robert, thank you all for your help and advice.
I did look at that diagram in the NCE manual. That would certainly be a solution for the continued use of the 2-leg bi-polar LEDs but, given the distance from the Tortoises to the control panel, I would either have to relocate the Switch-8 to the control panel or bring two wires to the control panel from the Tortoise and 2 more wires back to the Switch-8 if I wanted to keep it close to the Tortoises.
I will just use 3-leg bi-polar LEDs on the control panel with a wire from a nearby DC power pack to complete the circuit. That has been my dilemma, where to get a source of constant power to the LEDs once I use momentary push buttons to trigger the Mini Panel.
It's just one wire in my option. But you should already have 2 wires from the control panel to each Torotise, from the old DPDT toggles.
rrinker It's just one wire in my option. But you should already have 2 wires from the control panel to each Torotise, from the old DPDT toggles. --Randy
Yeah, the two power wires to the Tortoise terminals #1 and #8 can just be switched to the #4 and #5 terminals on the Tortoise. I'll just bring up a wire from the DC power back which is right below the control panel to a 3-leg LED to complete the circuit. I had the 3-leg LEDs on hand, but I was just curious if the 2-leg LEDs could be salvaged for this project. It was mostly intellectual curiosity about whether and how power could be supplied to the 2-leg LEDs once the DPDTs were gone, replaced by the momentary, normally open, pushbuttons. I appreciate the answers to that question.
richhotrain greg, Randy, and CSX Robert, thank you all for your help and advice. I did look at that diagram in the NCE manual. That would certainly be a solution for the continued use of the 2-leg bi-polar LEDs but, given the distance from the Tortoises to the control panel, I would either have to relocate the Switch-8 to the control panel or bring two wires to the control panel from the Tortoise and 2 more wires back to the Switch-8 if I wanted to keep it close to the Tortoises...
I did look at that diagram in the NCE manual. That would certainly be a solution for the continued use of the 2-leg bi-polar LEDs but, given the distance from the Tortoises to the control panel, I would either have to relocate the Switch-8 to the control panel or bring two wires to the control panel from the Tortoise and 2 more wires back to the Switch-8 if I wanted to keep it close to the Tortoises...
There would be no reason to run two more wires. Here is a diagram showing how to do it:
Oh, I see my error in thinking that I would need four wires, two to the control panel and two back to the Switch-8. Duh, I would need just one to the control panel and one wire back to the Switch-8. I don't know why electronics is so hard for me to grasp.
I need a simple drawing program so I can make pretty pictures, if I draw it with Paint it looks like a crayon drawing. Anyway, what I was getting at is that you cna continue to use the saem 2 leg LEDs and just run ONE wire from the Tortoises back to the panel. You need a bipolar power supply, like the one option shown in the Tortoise diagrams for using a SPDT toggle. The + and - lines from the power supply daisy chain to each Tortoise, pins 2 and 3. Pin 4 of the Tortoise is the one wire you run back to the panel. You also run the common lead of the power supply to the panel - ONE time, and daisy chain it to one side of each LED. The one wire from pin 4 of each Tortoise goes tot he other leg of the specific LED for that turnout. You will need to add a resistor to each LED as well. But, the two lead bicolor LEDs stay.
How this works is, when the Tortoise is one way, it connect the LED between the negative and common. Common therefore is positive, relative to the negative side. So whichever color LED inside the bicolor LED is wired that way will light up. Move the Torotise the other way, the leg of the LED connected to the Torotise is now positive, compared to common, which is eacatly the opposite polarity, so the other color LED inside there will light up.
It really works. You can test it - take a pair of 9V batteries. Connect the + of one to the - of the other. This is your common point. Hook up a 1K resistor between this common point and one lead of the bicolor LED. Touch the other lead to the free + terminal on one battery - it will be red or green depending on which way you hooked up the LED. Now touch that LED lead to the free - terminal of the second battery - if it was red, now it will be green, or vice-versa.
You'd think this simple demonstration would already be drawn somewhere that I could find on Google, but you'd be wrong, apparantly.
In this diagram, just replace the DS44 with your *corrected* switch - 8 *corrected*. They work on the same principal. (Not shown in the diagram is your two wires for the momentary push button which go to the mini panel.)
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
The minipanel doesn;t drive the Tortoise, the minipanel generates switch commands that are controlling Switch8's which drive the Tortoises. The Switch 8's are going to be located near the Tortoise they are controlling, so the simple method of just putting the LED in series with the motor drive would mean having that all run back to the control panel.
However, I suppose nothing actually prevents putting the Minipanel AND the Switch8 behind the control panel and then reusing the same two wires already running to the Torotise pins 1 and 8. The stationary decoder doesn;t HAVE to be placed close to the switch motor.
rrinker However, I suppose nothing actually prevents putting the Minipanel AND the Switch8 behind the control panel and then reusing the same two wires already running to the Torotise pins 1 and 8. The stationary decoder doesn;t HAVE to be placed close to the switch motor.
Randy, I agree with you.
As I have been reading through all of these helpful replies, it dawned on me that since I am running wires back to the control panel anyhow, I might just as well put the Switch-8, Switch-It, and Mini Panel on the control panel. Or should I say inside the control panel since I built it boxlike and the cover hinges forward to access the toggle switches, LEDs, and wiring.
richhotrain rrinker However, I suppose nothing actually prevents putting the Minipanel AND the Switch8 behind the control panel and then reusing the same two wires already running to the Torotise pins 1 and 8. The stationary decoder doesn;t HAVE to be placed close to the switch motor. Randy, I agree with you. As I have been reading through all of these helpful replies, it dawned on me that since I am running wires back to the control panel anyhow, I might just as well put the Switch-8, Switch-It, and Mini Panel on the control panel. Or should I say inside the control panel since I built it boxlike and the cover hinges forward to access the toggle switches, LEDs, and wiring. Rich
Eureaka! This would be the way to go - evrything would be done inside the control panel and you don't even have to venture underneath the layout(unless you've already started re-wiring things). Now why didn't any of us think of this several posts ago?
The Switch-8, Switch-It and Mini Panel are all enroute from MB Klein. Had I had them in hand, I probably could have been more helpful by doing some trial and error wiring. I am unfamiliar with exactly how they operate and how they are wired, so this is a learning process for me from the get go. But, I am learning a lot just from this thread, and I appreciate all of the help and advice.
Definitely try it out, I had one Switch-It to try out, since they work with any DCC system, and the output voltage was already on the low side, dropping another 2.1 volts through an LED might make it too low. But since it's driven off track voltage, that also had an effect - my Zephyr only puts about 12.5V tot he rail instead of 14-15 that most systems do (at least on the HO setting). I no longer have it to try with my expanded system using a DB150 to drive the rails which does put out the higher voltage. No idea on the Switch-8, they weren't around back then.