Some last minute ques. about installing my tortoises (at last).
I have a variety of wire on hand, but the most useful (because it is bundled in 4 strands) is the 20 gauge solid copper wire I use for feeders. Could I use this for a 16 foot runs from the 7.7 V 1.5 Amp power source I will be using? (The power source actually puts out 10 volts.)
Second ques....I want to have control of the tortoises from both the DPDT at the control area and a DPDTswitch near the turnout on the layout because they are 16 feet from the control area. Can I wire up two of the DPDT switches 16 feet apart, and soldered to the motor?
I know how to do the wiring, I just wonder if there is a good reason not to have these controlled by two switches in separate locations.
Yes, the 20 gauge wire should be good for that length, but....it really depends on how the active device responds to, or is affected by, drops in voltage over that distance.
This calculator
http://www.powerstream.com/Wire_Size.htm suggests that you can anticipate a drop in voltage near 0.1 volts over 16 feet, so it's hardly going to be a problem. I entered an amperage draw of only 0.3, but you can figure out what is more appropriate for your intended use.
Crandell
Since a Tortoise draws a maximum of 18ma, the voltage drop over thin wire will be negligible. You can safely use telephone wire, which is 24-26 gauge.
You can put two DPDT switches in series - however it will be like the "two way" switches in your house - they don't always agree. But it will work.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Agreed that 20 gauge is plenty. There was a thread recently that discussed using 2 dpdt switches. They will work fine. Also make sure the power supply has a DC output.
Springfield PA
Thanks, Gentlemen.
The three Tortoises went in smoothly and test out fine. Now I can wire them up as I wish thanks to your responses.
I was just sweating a little over this installation because I am using them on three quite expensive large radii curved turnouts and worried over the hole alignment etc. etc. since the turnouts are siliconed down and soldered in. I suppose I could have just left them pinned down while I did the Tortoise installs.
If the turnout is already installed I typically take a putty knife and slide it between the throwbar of the turnout and roadbed to protect it while drilling from underneath.
It takes an iron man to play with a toy iron horse.
MisterBeasleySince you're controlling these with dual DPDT toggles, the turnout position will not always be indicated by the toggle position. So, I'd recommend installing LED indicators. These can be either on the control panel or on the layout as signals. You'll appreciate them the first time you turn the lights down low and run night trains.
The one problem with LED indicators on dual DPDT toggles is that the light at one toggle switch may give an erroneous signal.
Say the toggle switch is down for straight hrough and up for divergent, and the LED is green for straight through and red for divergent on the main control panel. Now, flip the dual DPDT toggle up on the secondary control panel and the LED turns red. But, on the main control panel, the toggle is still down and the LED is still green.
The solution is to wire a second LED to show the color on the other control panel panel. A mismatch of red and green LED's calls for corrective action.
Rich
Alton Junction
richhotrain The solution is to wire a second LED to show the color on the other control panel panel. A mismatch of red and green LED's calls for corrective action. Rich
A much more simple LED solution would be to have two bi-color LEDs wired in parallel with each other and the pair of LEDs then wired in series between the two DPDT switches and the Tortoise. Mount one LED near each switch.
Regards,
Dave
From Mt Pleasant, Utah, the home of the Hill Valley and Thistle Railroad where the Buffalo still roam and a Droid runs the trains
Dave Merrill richhotrain: The solution is to wire a second LED to show the color on the other control panel panel. A mismatch of red and green LED's calls for corrective action. Rich Rich A much more simple LED solution would be to have two bi-color LEDs wired in parallel with each other and the pair of LEDs then wired in series between the two DPDT switches and the Tortoise. Mount one LED near each switch. Regards, Dave
richhotrain: The solution is to wire a second LED to show the color on the other control panel panel. A mismatch of red and green LED's calls for corrective action. Rich
Dave,
That is interesting. Can you elaborate?
If you wire the LEDs in the fashion you mentioned, will each LED correctly light the color that the turnout is thrown. In other words, regardless of the postion of each toggle (up or down), will both LEDs be green or both red? Or, will each LED be a different color as a toggle switch is flipped?
If you wire them in true parallel, then they would both be the same color at the same time, which is the idea here - having an indicator at both toggle locations that shows the true position of the turnout, since the toggles won't agree. Wire them anti-parallel (have to experiment since bi-color LEDs often don;t have any differentiation other than one lead longer than the other, since they light up no matter which way you connect them, unlike a regular diode) and one would be red while the other is green - that's the way to wire them for a single toggle at one location with a track diagram - the selected route would be green and the other wya would show red.
You can use two pairs of diodes to get a red and green indicator at toggle switch. It means more wire back and forth, but you'd hook one opair up to be red and the other green in a given position, and put one red and one green at each toggle location. flip either toggle and change the Tortoise, and the red lights will now be green and vice-versa.
I may be missing something here but.... If we are talking about two (or more) toggles controlling ONE Tortoise, then why wouldn't a single bi color LED in series with one leg of the Tortoise motor work as well as the solutions given here? I haven't worked out on paper, just thinking.
73
Bruce in the Peg
Well I'm thinkign the only reason you'd need TWO toggle switches is to operate the turnout from two different positions - say opposite sides of the layout. So with just one LED, it would have to be on one side, and you couldn't see it from the other side. And since you can't go by toggle position.... Sure, you could put the single LED ont he layout like a dwarf signal next to the turnout and get away with just one, but for a fascia panel application you'll need one at each operation position - there isn't a limit, really, you can wire a dozen DPDT toggles in series with the Tortoise and control it from a dozen different positions if you wanted to. The limit is the LEDs - more than 2 or maybe 3 will drop the voltage to the Tortoise motor too much, so if you need lots of indicators you'll need to use the Tortoise contacts to control them all instead of the simple series wiring.
If you have a bipolar power supply(easily made with two matching regular power supplies), here is a circuit that will let you control a Tortoise from two locations and gives LED indication of the alignment at each location wihtout requireing running a bunch of wires back and forth: