I need an answer to a question that has perplexed me for nearly 14 years.
When I built my first HO scale layout, I installed Tortoises to power my turnouts, and I installed some dwarf signals and trackside searchlight signals from Tomar Industries. My signals are connected to the internal switches of the Tortoises. My power source is an MRC Railpower 1370 power pack.
The Tomar signals use a white wire as the positive and red and green wires as the negative. I connect resistors on the red and green wires to protect the LEDs. One of my questions relates to the #4 and #5 terminals on the Tortoise. The Circuitron literature doesn't specify positive versus negative, but I recently found a diagram that indicates that #4 is positive and #5 is negative. I always install a black wire on #5 and consider it the negative side necessary to complete a circuit. The two screw terminals on the DC side of the MRC Railpower 1370 are marked + and -.
When I first set up my wiring protocol, not knowing any better, I ran black and white wires all the way back to the power pack for each signal and each Tortoise - - a wiring nightmare that I now regret. So, I am in the process of installing 14AWG black and white bus wires down the center of the layout so that I can connect the individual black and white wires at their source, cutting down substantially on the amount of wire under the layout.
This all seems simple enough, but it isn't, at least for me. Sometimes, I have to connect black wires to the positive terminal of the power pack and white wires to the negative terminal of the power pack. So, that is my other question. Since the Tomar signals always use the white wire as positive, are the internal switch connections on the Tortoise sometimes reversing my wiring protocol?
I hope this all makes sense.
Rich
Alton Junction
Switchs (as in electrical switches) have no poolarity, nor any active components that could reverse the polarity. They are, in the case of the Tortooise, literally some slabs of metal on the circuit board with wipers that touch them and connect 5 to either 6 or 7, depending on which way the Tortooise moves. It is exactly the same as if you took the wire off of pin 5 and then alternately touched it to the wire connected to pins 6 and 7.
So if in some cases you need to swap the wires around, either somewhere you reversed the connection.
Or - does Tomar sell signals both ways, common anode and common cathode? Or are some of your signals another brand? That common wire might not always be + on the signal. If they are common anode it is, and the colored wires from each LED are the -, but if the signal is common cathode, then the common side is the - and the wire from each LED is +.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks, Randy, for that reply. It got me to thinking that maybe not all Tomar Industries signals are wired the same way. The white wire on the dwarf signal is positive according to the instruction sheet, so I just assumed that the search light signal is also positive. It is not. I called Tomar and was told that the white wire on the search light signal is negative. Go figure. So, that explains my confusion.
Regarding the Tortoise internal switch, since it is not polarity specific, I assume that means that to complete a circuit, the black wire on #4 or #5 should be wired to the opposite polarity terminal on the DC power pack than the polarity of the signal that it controls. Is that correct?
That is correct, the common of the Tortoise contacts, either 4 or 5, goes to the power supply. The 'stationary' contacts (the whole thing moves in the Tortoise, unlike the typical demonstration of a knife switch) go to one of the LEDs in the signal. That's 2 and 3 when 4 is the common, and 6 and 7 when 5 is the common. Tortoise instruction sheet shows the arrangement.
Thanks, Randy. I appreciate the help.
richhotrain Randy. I appreciate the help.
Randy, I will add my thanks as well. I now have a much better understanding of what goes on inside the wee beasties!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hon30critter richhotrain Randy. I appreciate the help. Randy, I will add my thanks as well. I now have a much better understanding of what goes on inside the wee beasties! Dave
Where would we be on this forum without Randy?
Some of us will be fine........No offense Randy....
Take Care!
Frank
If you think it's complicated using the Tortoise contacts to switch the signals, consider a more complex signal system that uses electronics to drive the signals. The circuit required to drive common anode signals (+ is common) is completely different than the circuit needed to drive common cathoode (- is common) signals.
It's possible, when the 'driver' is a microcontroller, to flip between modes using code, so a device like the Digitrax SE8C can be set to run either type of signal. What mode controllers don;t have though, is a mix and match mode. It's either all CA, or all CC. I'm rather surprised that Tomar makes some types of signals one way and other types the opposite way - usually within a manufacturer they are consistent - it's when you combine signals from different companies you run into problems like this.
zstripe Some of us will be fine........No offense Randy.... Take Care! Frank
Richie
rrinker ---snip--- I'm rather surprised that Tomar makes some types of signals one way and other types the opposite way - usually within a manufacturer they are consistent - it's when you combine signals from different companies you run into problems like this. --Randy ---end snip---
---snip---
I'm rather surprised that Tomar makes some types of signals one way and other types the opposite way - usually within a manufacturer they are consistent - it's when you combine signals from different companies you run into problems like this.
---end snip---
I believe I can clear up the choice of common situation with Tomar signals. All of their "2 and 3 light" signals (i.e. individual red, yellow and green LEDs) use a common anode/positive. Their "older" searchlight style signals (single "lens" with red/green LED behind it) used a common cathode/negative because that was the way those 3-wire red/green LEDs typically came. However, Tomar has recently shifted to the more modern approach to searchlight signals which use a common anode LED with red, yellow, and green elements within it. So ultimately your wiring, or choice of signal circuit, will depend on which style of signal you have and possibly which vintage of signal it is!
LogicRailTech rrinker ---snip--- I'm rather surprised that Tomar makes some types of signals one way and other types the opposite way - usually within a manufacturer they are consistent - it's when you combine signals from different companies you run into problems like this. --Randy ---end snip--- I believe I can clear up the choice of common situation with Tomar signals. All of their "2 and 3 light" signals (i.e. individual red, yellow and green LEDs) use a common anode/positive. Their "older" searchlight style signals (single "lens" with red/green LED behind it) used a common cathode/negative because that was the way those 3-wire red/green LEDs typically came. However, Tomar has recently shifted to the more modern approach to searchlight signals which use a common anode LED with red, yellow, and green elements within it. So ultimately your wiring, or choice of signal circuit, will depend on which style of signal you have and possibly which vintage of signal it is!
richhotrain zstripe Some of us will be fine........No offense Randy.... Take Care! Frank Frankie, you are such a meanie. Richie
Frankie, you are such a meanie.
I'm not being a ''meanie"....I'm being honest. When I started into the HO scale side of the hobby in 1950....Randy wasn't born yet! You learned on Your own.
Frankie
Hi Frank,
C'mon, man, I am just pulling your chain. So, instead of, what would we do without Randy, let me say, what would I do without Randy. I will let the rest of you speak for yourselves.
Rich........Yeah, but You had the chain around My neck.......
Take Care, grasshopper! LOL.
zstripe Rich........Yeah, but You had the chain around My neck....... Take Care, grasshopper! LOL. Frank
Frank, I find you to be the most interesting man in the world.
Where would we be on the forum without Frank?
Even I learned a loot oof it oon my own - out of self defense. I wanted too run trains, and my dad was at work, so I proceeded to figure out the missing wires and had the trains running when he got home - I was only 5. What's crazy is that this started me down a path where by the time I started HS I knew I wanted to go to college for electrical engineering, yet here I am 29 years out of school and only just really started to do any real electrical engineering, designing my signal and detection system. Sure I've dabbled a little here and there, but my first job out of college, I quickly took a sharp turn into computer networking and application development. And I'm always learning. I've never laid out a PC board, but I'm learning that now - my servo driver and signal controller, I will need too many boards to do them all as point to point wiring, so I will be having PC boards made.
That's a great story, Randy.
Yeah, when I went to bed the night before, only the track in the front was in place. I got up the next morning and went down to watch cartoons (it was saturday morning) and I saw all the track was in place, completing the loop. So I put a train on the track and ran it, it got half way and just died. So I crawled up on the layout (literally) and started hunting around, I saw the plastic joiners near where the train stopped moving, and then I found the other terminal track in the back. Fished out some wire, and hooked it up, boom, train was running.
Somewhere in all my moves I've lost the pictures of what we used to set up over the holidays. The final one occupied all available space and was 4x10 with an extra bit grafted on along the 10' side to make it slightly wider than 4' so a loop of 22" radius could be fit without being close to the edge - all in sections, 2 of them 4x4, then a 2x4 piece and the extensions, long and narrow pieces, all with various cleats to secure them together when set up. 2 main loops, an inside trolley loop through the town, and one of those Lionel HO section gang cars (I always called it a bumper car) running halfway up the mountain, plus one of those operating cable car sets from the base up to the ski lodge on top. I forget how many turnouts. My Dad built it all but he could never run the trains without running a switch somehwere and derailing - i was the only one who could consistently run trains. Mostly Typco and Life Like stuff, and some AHM. Some of the pieces were older than me - Flyer HO industrial diesel, a Tyco 0-6-0T, and some cars. Nicest thing we had was the Rivarossi streamlined Hudson - hence the extensions for the 22" radius curves. The cars it pulled - well, we were not prototype modelers of any sort, the passenger consist was Tyco Santa Fe cars from their F7 passenger set. And one AHM IC dome car I later hacked up in an attempt to follow an MR Paint Shop article on making a business/track inspection car.
richhotrain hon30critter richhotrain Randy. I appreciate the help. Randy, I will add my thanks as well. I now have a much better understanding of what goes on inside the wee beasties! Dave What has always confused me has been my wiring protocol. Since Tomar Industries uses a white wire for the common, I use a black wire on the Tortoise. It all seemed so simple. White as one polarity, black as the other. Little did I know that some Tomar signals use white for positive (+) and other signals use white for negative (-). And, to make matters worse, I thought that the Tortoise internal switches were polarity specific. Where would we be on this forum without Randy? Rich
What has always confused me has been my wiring protocol. Since Tomar Industries uses a white wire for the common, I use a black wire on the Tortoise. It all seemed so simple. White as one polarity, black as the other. Little did I know that some Tomar signals use white for positive (+) and other signals use white for negative (-). And, to make matters worse, I thought that the Tortoise internal switches were polarity specific.