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Best decoder for a Tortoise?


Mike53A
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Let's call the Tortoises Master and Slave. My installation is more than 10 years old, and I have Hare decoders on the Master Tortoise, but let's see if we can work it out. The input from your decoder to the Master Tortoise goes to #1 & #8, obviously.  Now connect #2 & #7 on the Master to #1 & #8 on the Slave. Now on the Master put short jumpers between #1, #3 and #6, and another pair between #4, #5 & #8. If the points don't reverse relative to each other, swap #1 and #8 on the Slave.

 

Can someone please check my logic on this! 

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Thanks Nigel, that’s exactly the  way I had it wired with a split power supply and analogue switching. The track and loco’s were all DCC.
 

I’ve now taken the decision to go the whole hog and drive everything via DCC. What confused me from the US circuit was the NCE MK8 which I took to be a Switch 8 mk2. It then appeared to be a half ‘n half, DCC with a split power supply.

 

Thanks Warren, once the ECoS turns up I’ll hook it up and see what happens. Driving more than 2 or 3 may be an issue in which case route setting may be the answer.

I

Edited by gordon s
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Cheer’s Ian. I was fine until the polarity was reversed. Unfortunately I can’t do much right now as I’m hooked up to my two weekly drip for the next hour or so. Could be worse though. Stretched out on the sofa in the warm, glass of Shiraz and England Six Nations Rugby on the TV......:drink_mini:

 

Seems the message didn’t reach the French.....:mellow:

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40 minutes ago, Nigelcliffe said:

 

From a cursory glance at the diagram, I think they are assuming a split power supply.  Which has +volts, 0volts and -volts.  This reduces the amount of wiring to the switch panel needed to operate tortoise.     Th split power supply can be achieved in two common ways:

 

 

 

 

- Nigel

Yes, but it shows the first Tortoise being powered by one connection to a NCE "MK8" (whatever that is supposed to be!) with the other connection going to ground.

That is not how a Switch-8 is, or can be, connected.

 

I found another reference to an NCE "MK8" on the web and it also seemed to be a Switch-8 that was being talked about

http://cs.trains.com/mrr/f/744/t/259949.aspx

 

No wonder people get confused.

 

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1 hour ago, gordon s said:

Thanks Ian. I thought that was what the US guys was suggesting, but can't get my head round how the polarity to the second motor is reversed via the switch contacts. How are you making those connections?

 

OK, I have another question which is beyond my existing knowledge base....;)

 

On my layout I have four parallel tracks with a crossover from track 1 to track 3. Where it crosses over track two there is a switched diamond crossing, so each turnout has its own Tortoise and the switched crossing has two Tortoise motors.  I'm guessing I can't run all four motors from one decoder, so any suggestions how to deal with the switching so that it is foolproof and you can't have conflicts?

 

In actual fact, looking at the pic, the turnout up towards the knife handle also comes into play, so there are five motors involved. Should they have separate inputs to the Switch 8 separate and the switching made via route setting in the ECoS?

 

I think the idea of daisy chaining the Tortoises is so that they don't all throw at once (and perhaps as importantly draw current at once), in which case it may be possible to drive more than two Tortoise from the same Switch 8 output - possibly even all five in your scenario above.  Think of the Switch 8 as being like a simple mechanical switch.  When you switch it on, it makes a circuit and power will be fed to the first Tortoise but only to the one connected directly to the Switch 8 (or a mechanical switch).  Once that Tortoise has thrown fully across, the switch output on the first Tortoise will make the circuit to provide the power to switch the second Tortoise.  The second Tortoise won't start to move until the first one has fully thrown, so its demand for current will be after the first.  Similarly, if you were to route power to the third Tortoise through the switch contacts on the second Tortoise and route power to the fourth Tortoise through the switch contacts of the third Tortoise, and route power to the fifth Tortoise through the switch contacts on the fourth, then I think you should be able to switch all from a single Switch 8 output.

 

Note however that I haven't tried this and don't have any practical experience with either the Switch 8 or Tortoise motors.

 

 

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2 minutes ago, Dungrange said:

 

I think the idea of daisy chaining the Tortoises is so that they don't all throw at once (and perhaps as importantly draw current at once), in which case it may be possible to drive more than two Tortoise from the same Switch 8 output - possibly even all five in your scenario above.  Think of the Switch 8 as being like a simple mechanical switch.  When you switch it on, it makes a circuit and power will be fed to the first Tortoise but only to the one connected directly to the Switch 8 (or a mechanical switch).  Once that Tortoise has thrown fully across, the switch output on the first Tortoise will make the circuit to provide the power to switch the second Tortoise.  The second Tortoise won't start to move until the first one has fully thrown, so its demand for current will be after the first.  Similarly, if you were to route power to the third Tortoise through the switch contacts on the second Tortoise and route power to the fourth Tortoise through the switch contacts of the third Tortoise, and route power to the fifth Tortoise through the switch contacts on the fourth, then I think you should be able to switch all from a single Switch 8 output.

 

Note however that I haven't tried this and don't have any practical experience with either the Switch 8 or Tortoise motors.

 

 

Note,

The Tortoises draw the most current when stationary, when moving the current draw drops to about one third of that when stationary.

So you are not saving current by "daisy chaining" in that fashion.

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7 minutes ago, melmerby said:

Note,

The Tortoises draw the most current when stationary, when moving the current draw drops to about one third of that when stationary.

So you are not saving current by "daisy chaining" in that fashion.

 

Okay - I has assumed peak current draw was during movement, but if the peak is at stall (which seems to be the case), then you're right - you can't connect more than two per output.

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1 hour ago, melmerby said:

 

Quote

From a cursory glance at the diagram, I think they are assuming a split power supply.  Which has +volts, 0volts and -volts.  This reduces the amount of wiring to the switch panel needed to operate tortoise.     Th split power supply can be achieved in two common ways:

 

 

Yes, but it shows the first Tortoise being powered by one connection to a NCE "MK8" (whatever that is supposed to be!) with the other connection going to ground.

That is not how a Switch-8 is, or can be, connected.

 

I found another reference to an NCE "MK8" on the web and it also seemed to be a Switch-8 that was being talked about

http://cs.trains.com/mrr/f/744/t/259949.aspx

 

No wonder people get confused.

 

 

It is as you describe.   So as your earlier post says, there has to be another +V,0V,-V  power supply in the setup.  

 

I can't think of a reason why that power couldn't come from the DCC power, by using a couple of fast-recovery rectifier diodes (treat the DCC as an AC power source), plus perhaps something (resistor?) to push the voltage down a bit as voltage might otherwise be a bit high for the tortoise.   But a separate power supply is usually cheaper than taking current from a DCC system, unless the system has lots of surplus power which will never be used. 

 

 

And, yes, not surprised at the confusion!

   

 

 

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18 minutes ago, Dungrange said:

 

Okay - I has assumed peak current draw was during movement, but if the peak is at stall (which seems to be the case), then you're right - you can't connect more than two per output.

They are like any device with a DC motor, if they are running freely they consume less current than when stationary (or stalled.)

The motors are very high resistance so a continuous 12v when stalled will not overheat them. (typically less than 200mW)

 

 

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7 minutes ago, Nigelcliffe said:

 

It is as you describe.   So as your earlier post says, there has to be another +V,0V,-V  power supply in the setup.  

 

I can't think of a reason why that power couldn't come from the DCC power, by using a couple of fast-recovery rectifier diodes (treat the DCC as an AC power source), plus perhaps something (resistor?) to push the voltage down a bit as voltage might otherwise be a bit high for the tortoise.   But a separate power supply is usually cheaper than taking current from a DCC system, unless the system has lots of surplus power which will never be used. 

 

 

And, yes, not surprised at the confusion!

   

 

 

With the Mk2 you can use an external 9-15v DC supply, thus saving any drain on the DCC system.

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Really, on a big complex layout , you need a separate layout control bus , preferably bi directional . So you cam feed back point blade position and or track section occupancy. 

 

MERG CBUS would be ideal , if you are prepared to do some simple soldering. It’s also the cheapest system around and there are modules to drive stall motors , solonoids etc. hence a mimic panel /switches etc can be easily build up at minimal cost. You could also integrate virtual mimic panels via JMRI 

 

( disclusure , I am a MERG member , ,I am also responsible for a big O gauge layout ,55 cobalts , 20 semaphores , 25 ground discs , track section occupancy,   DCC  for traction  only , Z21 )

 

ps another system worth looking at is the Megapoints system. But it’s not connectable to DCC 

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24 minutes ago, Junctionmad said:

ps another system worth looking at is the Megapoints system. But it’s not connectable to DCC 

 

Megapoints is primarily for servo motors, not tortoise.  So, yes if a change to the motor type in the thread title.

 

It can connect to DCC - there is a DCC module add-on in the Megapoints catalogue, so the MegaPoints system acts as a number of DCC Accessory Decoders.  There are constraints that then imposes (in some module combinations it will end up as either DCC controlled, or they are panel controlled, not both), so read the documentation carefully before commiting to the approach.   

The Megapoints website (blog?) has discussed more advanced connections, including a bi-directional computer link to software such as JMRI, no idea if that's available yet as a product. 

 

- Nigel

 

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 Came across this while looking for exactly this question. Have read the thread but am a little confused so wanted to list My exact questions if that’s OK.

 

i have ECoS and Tortoise and need a suitable Decoders, which i see from this thread is either the NCE Switch 8 or DCC concepts — which seems to be about 3/4 the price of the First.

 

1: can the DCC concepts AD8fx also handle crossovers — is 2 tortoise at once?

2: I assume 8 outputs means 8 points and not 4 points in 2 directions...... ( sorry been away from DCC for a while and want to be sure)

3: if I use the panel setting on the ECoS will both show how the Point is set on the Panel Display? (Read something about Railcom but not sure if this is a concern here?)

 

thanks Russell

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I have exactly that set up, Russell. ECoS, Switch 8's and Tortoise motors and they work perfectly.

 

The answers to your questions as follows:

 

1. Yes. No problem. Just connect the two motors together and then take a pair of leads to the Switch 8 output. If one is reversed, just reverse the leads between the two motors.

2. Yes. 8 turnouts.

3. Yes. You will need Railcom switched off on the ECoS. Easy to do.

 

It's great to be able to set routes and find the turnouts switching one after another.

 

 

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Hi Russell,

Yes - a DCCconcepts AD8FX can accept 2x Tortoises on one output for a crossover pair.

It is also 8 discrete channels - all individually addressable.

It does not have Railcom capability, but if you change the point from your ECoS, the ECoS display will mirror that command.

 

If you are not using Railcom, then no issues anyway.

 

Best Regards,

The DCC Team.

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20 hours ago, DCCconcepts said:

Hi Russell,

Yes - a DCCconcepts AD8FX can accept 2x Tortoises on one output for a crossover pair.

It is also 8 discrete channels - all individually addressable.

It does not have Railcom capability, but if you change the point from your ECoS, the ECoS display will mirror that command.

 

If you are not using Railcom, then no issues anyway.

 

Best Regards,

The DCC Team.

Thank for that. 
Am I Right in thinking the only use for Railcom is showing the loco number and it’s position?
 

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1 hour ago, russellwar said:

Thank for that. 
Am I Right in thinking the only use for Railcom is showing the loco number and it’s position?
 

 

Yes - according to this from the DCC Wiki:

 

What Can RailCom Do?

Locomotive Identification. When a RailCom equipped multi-function decoder enters a section of track with a detector, its presence will be immediately noted. At the same time you'll know where your train is.

Info Display: A number of items can be supplied by the multi-function decoder: Speed, fuel, water level, etc.

Data read back: It is possible to display CV values during programming, and acknowledge commands

Unknown multi-function decoder: If a new locomotive is introduced to the layout, you can find out its address, and even allow a throttle to acquire it automatically.

RailComPlus adds the ability to read the multi-function decoder's function capabilities and automatically register the locomotive with the command station.

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9 hours ago, newbryford said:

 

Yes - according to this from the DCC Wiki:

 

 

Thanks for clearing that up.

do you have a link to this please so I can look things up myself. Checked Wikipedia and the DEMU Wiki and could find that text so wondering if there is a decent online resource. Thanks Russell 

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2 hours ago, russellwar said:

Thanks for clearing that up.

do you have a link to this please so I can look things up myself. Checked Wikipedia and the DEMU Wiki and could find that text so wondering if there is a decent online resource. Thanks Russell 

Strangely the DCCWiki is actually at DCCWiki!

https://dccwiki.com/

Searching for Railcom:

https://dccwiki.com/Railcom

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