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Power frog when track glued down

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Power frog when track glued down
Posted by Buschy on Tuesday, January 27, 2015 5:04 PM

I am in the process of installing LEDs on my control panel to indicate point direction. A green light will illuminate either on the left or right track on the little track diagram on my control panel.

It is my understanding that I first need to run a wire from terminal 3 on my digital cobalt motors to each frog for polarity. The problem is that my track is already glued down onto the plastercloth that sits on top of Woodland Scenics risers. No access to underneath the frog(s) unless I start ripping track up. Is there a way of neatly connecting a wire to these frogs from above the bench? I also am using Hornby point clips at present, they seem to be working well, no DCC issues so far. However, not sure if having these point clips influences how frogs are to be wired for the LEDs? I am a novice when it comes to wiring and electronics. Confused

Once the wire from each motor to each frog is connected, the diagram in the cobalt manual then shows another wire running from frog back to each LED on control panel, along with either a positive or negative track wire depending on whether the LED is positioned on left or right track.

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Posted by mlehman on Wednesday, January 28, 2015 10:35 AM

The neatest solution is to solder a lead to the bottom of the rail in the frog. Won't work here, though.

Instead, you can tin the end of a wire, bend it into an L-shape, drill a hole next to the frog rail, drop the wire through it, then solder the tinned wire end against the side of the rail. If you do this to the backside of the rail -- away from the aisle side -- it's invisible under most viewing angles.

Mike Lehman

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Posted by carl425 on Wednesday, January 28, 2015 11:18 AM

When you look at the return on the labor investment, I believe powered frogs are overrated unless you run really short equipment.  If that's the case, Keep Alive decoders fix that and other pesky little track problems.

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Posted by gmpullman on Wednesday, January 28, 2015 12:07 PM

Hi, and Welcome

If I understand your question I believe you are confusing two different issues, or options, for using the switch options on the turnout motor. I do not have any Cobalts but I use Tortoises which I believe are nearly identical.

All you need to do for a panel indicator is place an LED (or a pair OR one two-lead bi-color LED) in-line or series, with one of the leads of the power going to the turnout motor. No need to use ANY of the switch contacts with this method.

As also mentioned here, you can use the auxiliary contacts to power a frog and you CAN carefully solder a small wire (22-28 gauge) to the frog and route it to the common switch contact. Either of the other contacts will be wired to "Rail A or Rail B" as called for in regards to point orientation.

Once you get the hang of what options you have with the switch motors you will understand it better.

I have some #10 turnouts on my layout and the frogs are powered because the frog is almost 2-1/2" long! Too big of a gap to span without reliable power.

Good Luck, Ed

 

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Posted by mlehman on Wednesday, January 28, 2015 2:15 PM

carl425

When you look at the return on the labor investment, I believe powered frogs are overrated unless you run really short equipment.  If that's the case, Keep Alive decoders fix that and other pesky little track problems.

 

To a certain extent, that's true, a recent fix for a very old problem. But it doesn't always work as well unless you're in HO or larger scales, because of the space needed. In HOn3, reliable operation depends on hot frogs, although some of the smaller keep-alives can fit some locos. Not sure any fit N scale yet, but they might eventually in factory installs that make room for them from the start.

Certainly it's more trouble to add a hot frog once track is down. If you use a Tortoise, Blue Point or other such gizmo, your contacts are already there, it's just a matter of three more wires to hook up, the red and black track power and the (usually green, it's a frog, right?) wire to the frog. Not very labor intensive , really if planned for from the start.

Mike Lehman

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Posted by carl425 on Wednesday, January 28, 2015 2:28 PM

gmpullman
I have some #10 turnouts on my layout and the frogs are powered because the frog is almost 2-1/2" long! Too big of a gap to span without reliable power.

Good point.  Without Keep Alive decoders I'd probably power those long ones too for insurance even though the other truck (I run diesels) would supply power most of the time.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by carl425 on Wednesday, January 28, 2015 2:36 PM

mlehman
it's just a matter of three more wires to hook up, the red and black track power and the (usually green, it's a frog, right?) wire to the frog. Not very labor intensive , really if planned for from the start.

Except 2 of the wires have to be hooked up twice.  I always get the polarity wrong on the first try. Super Angry

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Posted by rrinker on Wednesday, January 28, 2015 2:51 PM

 Precisely why I prepare my turnouts prior to laying track. Although on my previous layout, even my smallest loco handled the frogs just fine, even at slow speeds, so I never hooked the wires up. Now on my new layout, I will be using Peco Electrofrog which even on the smaller size have a larger dead section around the frog than the Atlas ones I used previously, so power is going to almost be required. Smaller locos with sound, it's a choice between sound and a decent speaker or a keep alive.

                    --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by mlehman on Wednesday, January 28, 2015 3:51 PM

carl425
Except 2 of the wires have to be hooked up twice. I always get the polarity wrong on the first try.

Yeah, but it's 50/50 odds, way better than the lottery.Smile

What I do sometimes when hooking up a number of them is to clip or position the leads to each rail so that the function on the multimeter that emits a signal when there's continuity is enabled. Everything has to be in the same block or section, but whenever you hear the noise you know it's wrong and you simply switch the leads. I'm somewhat dyslexic, so this is also a clear indication that, like a lot of things in life, the best choice is often the opposite of my first choice...Laugh

Mike Lehman

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Posted by Buschy on Thursday, January 29, 2015 12:41 AM
The thought of not having to use any of the switch contacts appeals (not wiring the frog), but I'm having trouble visualizing how the wiring would work with your idea. I did try a few different possible workarounds (without getting frog involved) but the best I could do was get the 2 green LEDs to light up at the same time. I couldn't get them to alternate, depending on whether the motor had the switch track positioned to the left, or to the right.
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Posted by floridaflyer on Thursday, January 29, 2015 9:19 AM

If all you want to do is install an LED on the control panel to show direction then re-read gmpullman's post. It is a simple installation.

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Posted by maxman on Thursday, January 29, 2015 12:21 PM

gmpullman
If I understand your question I believe you are confusing two different issues, or options, for using the switch options on the turnout motor. I do not have any Cobalts but I use Tortoises which I believe are nearly identical. All you need to do for a panel indicator is place an LED (or a pair OR one two-lead bi-color LED) in-line or series, with one of the leads of the power going to the turnout motor. No need to use ANY of the switch contacts with this method.

 

I agree that  frog power and LED power are two separate things.

However, doing some reading I find in several places that the Cobalt draws 30 milliamps when stalled.  According to Circuitron, who of course sells the competing product, this draw is "too high to safely wires LEDs in series with the motor".  See shortcoming 3 here: http://www.circuitron.com/index_files/Page697.htm.  I'm assuming that series wiring of LEDs may be done with suitable resistors installed.  In fact, the second or third diagram down here: http://www.re-os.nl/cobalt/Cobalt%20S%20manual%203%20Cobalt.pdf, shows a resistor installed.

So adding a resistor becomes an additional step, as I understand the subject.

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Posted by rrinker on Thursday, January 29, 2015 12:38 PM

 It is too much - LEDs are rated 20-25ma typically. Specialty ones for high brightness flashlights and so forth can take more, but also often need a heatsink.

                         --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by gmpullman on Thursday, January 29, 2015 12:41 PM

Thanks for clearing that up, Maxman. I only have experience with the Tortoise.

To Buschy, you have to orient the LEDs cathode to anode, or +- and -+ then wire that pair, with the resistor, in series with one lead to the motor, NOT across the motor leads.

Ed

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Posted by rrinker on Thursday, January 29, 2015 3:14 PM

 That won't work with the Cobalt you will be dropping the voltage to the motor too much. You can't put the resistor and LED in series with the motor. For indicator LEDs you have to use the contacts, or wire the LED and resistor in parallel with the motor connection. The diagrams in the Cobalt manual linked above show how to hook this up.

                   --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Buschy on Thursday, January 29, 2015 3:33 PM

I think problem has been solved. Page 3 of this link shows how it can be done. Cobalt Ip digital and digital work same way.

 

The frog wire doesn't have to go any further than the diode for LEDs to work.

http://www.dccconcepts.com/vamr/adding-led...-turnout-motors

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Posted by Buschy on Thursday, January 29, 2015 3:40 PM

Buschy

I think problem has been solved. Page 3 of this link shows how it can be done. Cobalt Ip digital and digital work same way.

 

The frog wire doesn't have to go any further than the diode for LEDs to work.

http://www.dccconcepts.com/vamr/adding-led...-turnout-motors

 

Correction...

http://www.dccconcepts.com/vamr/adding-leds-to-cobalt-turnout-motors

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Posted by maxman on Thursday, January 29, 2015 3:52 PM

Buschy
http://www.dccconcepts.com/vamr/adding-led...-turnout-motors

Something wrong with this link.  I get webpage not found.

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Posted by mlehman on Thursday, January 29, 2015 5:01 PM

Mike Lehman

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Posted by maxman on Thursday, January 29, 2015 5:17 PM

mlehman

 
thanks, works better.  However I don't understand why the method using their switches doesn't require a resistor.
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Posted by rrinker on Thursday, January 29, 2015 5:18 PM

 They must have made some changes, even to the Classic - when they first introduced them, at least for sale int he US, they were listed as 30-40ma, now they all say "typically 20ma". Now if it trulyt is 20ma or less, you can do series LEDs and no resistors. The fact that their diagrams recommend to use parallel LEDs and resistors as the best option though, leaves me to wonder. I'd do the parallel. If theya re the IP versions, it would appear what makes them "intelligent power" is that they cut off power to the motor at the end of throw - so no matter what the current, series LEDs won't work. You MUST use the contacts and wire as shown in the diagram.

 All this remains independent of frog power options.

                        --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by BroadwayLion on Friday, January 30, 2015 10:31 AM

You want to attch wires to tracks that are already in place.

Well NOBODY says that the wires must be invisible. Drilling down might not be an option since you might drill into the switch motor.

Sometimes thew wires are right out in fron of God and Everybody.

After all, railroads do not drill down it the the ground, now do they?

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by rrinker on Friday, January 30, 2015 4:24 PM

maxman
 
mlehman

 

 
thanks, works better.  However I don't understand why the method using their switches doesn't require a resistor.
 

 Do you mean #2 in that PDF file, using their toggle switches witht he little pc board on the back? Looks closely, upper right, there is a surface mount resistor on that circuit board.

                          --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by maxman on Friday, January 30, 2015 5:43 PM

rrinker
Do you mean #2 in that PDF file, using their toggle switches witht he little pc board on the back? Looks closely, upper right, there is a surface mount resistor on that circuit board.

No, actually #1, which I believe shows the LEDs wired similiar to the Tortoise wiring.  Maybe they have reduced the motor current draw.

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Posted by rrinker on Friday, January 30, 2015 7:49 PM

 Yeah, that's what I said before. The products section of their web site says the Cobalt Classic draws 20ma, which means you could put LEDs directly ins eries, same as a Tortoise. But their original ads for them, the specifications said 30 or 40 ma, which is way too much.

                       --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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