Robin Sundt Echini
I want to use the Mimic Red/Green LEDs to indicate the position of signals on a mimic board. I will be using a normal Alpha Mimic board and green LEDs driven by the DCC Bus to show the position of the points - but the signals are switched by a lever frame with interlocking driving servos through two Megapoints controller boards - these, in turn can drive a relay board that provides Common, NO and NC. The idea is to drive the Red/Green LEDs from the mimic accessory pack using this relay, but I can't find the wiring for the Red/Green LED other than it appears to have three wires running from it.
Given 12v +/- and the relay providing Common, NO and NC (and a resistor?), how can I wire up the Red/Green LEDs to switch colour when the relay switches?
Spoke to Mike and Richard at DCC today, who were very helpful and said it was possible, but I can't find the wiring for the Red/Green LEDs to work out how to do it.
Regards
Robin
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Julian
I'm making an assumption that the Servos will be DCC Accessory controlled by the Megapoints boards.  Assuming that is so, the Alpha Mimic can read those Servo Accessory command addresses and will change the LEDs for you.

If you give the Alpha Mimic board the same address numbers as the Megapoints DCC outputs {ie. Points Address No. X and the Mimic you want to light the 2 LEDs for those points, also number X} then the two LEDs you plug into Alpha Mimic will change accordingly.  Addressing the Alpha Mimic is very easy and well described in the instructions.

Hope this is in the right direction for you.

Regards
Julian
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Robin Sundt Echini
Thank Julian, but no, the Magapoints boards are driven by the switches on the lever frame (see the entry on Signals relating to Hayling Signals) and I understand that I cannot drive the DCC from the Megapoints boards - so I cannot use DCC for these signals. I can, and will use DCC to drive the mimic board for the points but the signals have a simple relay with Common, NC and NO.
I think that the wiring should be something like this:
Red-Green Mimic.jpg 
Assuming that this is the correct wiring diagram for the Red/Green Mimic LEDs:
Is the Centre wire the "common" with red on one side and green on the other?
Is the Centre wire the Positive or negative?
Does the Mimic Red/Green LED contain its own resistor or do I have to add one?
Is a 10k resistor correct?
Regards
Robin
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Julian
Yes, I saw the very impressive interlocking lever frame, brilliant engineering.

Your switches will operate the Megapoints board like the switch connections on the Peco Servo Boards, I get that now.  I have wired my Peco Switchmaster two ways.  Firstly through simple sprung to centre switched [left / right] and also to use the NCE controller.  The DCC Accessory commands are produced by the Alpha Encoder Board, which matches the Alpha Mimic.  The Centre sprung switches connect to the Alpha Encoder and sends the DCC commands and the Mimic picks them up.  I'm pretty sure that should work in the same manner from your lever switches, also to an Alpha Encoder.

Regards
Julian
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Robin Sundt Echini

Hi Julian,
Yes, I know I could use another encoder board but I would rather not. Much simpler to wire the Red/Green LEDs directly from the Megapoints relay board (C, NO, NC). 

Another encoder board costs - plus it requires a four core cable to the two existing encoder boards 12ft away - plus I intend to replace my current encoder boards when DCC eventually bring out the new mimic/encoder boards. 

So, the wiring questions remain!!
Regards
Robin

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Julian

Humm…  I was rather under the impression that the Alpha Mimic was a DCC item, with just the two DCC wire inputs.  Your conversation with Mike and Richard seems to indicate that there may be another way.  My control board and instructions are packed away for now, I will have a look in the morning.

It's only a minor point, in view of the main question asked, but the connecting 4 strand joining cable isn't essential, if your addresses are following on from the other two boards.  The additional one can be addressed from the first address input, with the rest of the addresses following in sequence.

Regards
J

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Robin Sundt Echini
HI Julian,
You are right, the Alpha Mimic board is an excellent DCC product that will drive the mimic LEDs just from a two wire connection to the DCC bus. But, that requires that each unit is broadcasting a DCC address onto the bus. And, I will use exactly that to drive the LEDs for the point motors that are switched by the signal levers as they will be switching DCC Cobalt Digital point motors.
That bit is easy. It is trying to display the signal positions on the same mimic panel that is not so easy because the signals don't use DCC but are driven by the signal lever microswitches working through the Megapoints servo board. It is possible to network the Megapoints boards but I understand that the DCC "connection" unit that Megapoints has will drive the Megapoints boards FROM the DCC Bus - but that it cannot drive the DCC bus FROM the Megapoints board. Also, because the DCC address of the points is from 1 to 6 and all the addresses from 1 to 24 are already taken up with points elsewhere on the layout, if I COULD send a DCC address from the Megapoints board INTO the DCC Bus, it would have to be a higher address than 24. So, if I did give each of the seven signals a DCC address, it would have to be over 24. That would mean that I would need TWO Alpha Mimic boards - one for addresses 1-6 for the points and another for the signal addesses of say 25 to 31. That is because you can only set the starting address for each Alpha Mimic board, you can't split the address in the middle. So, if I can wire the Red/Green LEDs directly along the lines of the diagram above, driven straight from the switches, it would be much quicker and easier and would not need any extra boards beyond the one Alpha Mimic board for the points.
Regards
Robin
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Julian
Haa!...  my goodness me.  That's a bit like thumbing a marshmallow into a moneybox.  There's loads of information there, but some items to think about.  If you will excuse me for the time being I have some ideas, which I would prefer to sleep on - more about how than what.

Perhaps Mike and Richard can beat me to it, but I will apply the little grey cells to my current thoughts in the morning.

J
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Robin Sundt Echini
Having built the signal lever frame and interlocking, all I want to do is to build a small mimic board next to the lever frame that shows the position of each point and each signal in that area of the layout. After speaking to the helpful folks at DCC Concepts, I can't think of an easier way to do it than to use an Alpha Mimic board to show the position of the six points in that section using DCC and green LEDs and then wire Mimic Red/Green LEDs directly to the Megapoints relays to show the position of each of the seven signals.
However, to do this I need to know the wiring configuration of the Red/Green Mimic LEDs - So I get back to my original questions...

Looking at the three wires attached to the Mimic Red/Green LEDs:
Is the Centre wire the "common" with red on one side and green on the other?
Is the Centre wire the Positive or negative?
Does the Mimic Red/Green LED contain its own resistor or do I have to add one?
If I need to add a resistor, is a 10k resistor correct to balance brightness with the Green LEDs driven by the Mimic board?

Regards
Robin
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Julian
Hi Robin,

Having built the signal lever frame and interlocking, all I want to do is to build a small mimic board next to the lever frame that shows the position of each point and each signal in that area of the layout. After speaking to the helpful folks at DCC Concepts, I can't think of an easier way to do it than to use an Alpha Mimic board to show the position of the six points in that section using DCC and green LEDs and then wire Mimic Red/Green LEDs directly to the Megapoints relays to show the position of each of the seven signals.
However, to do this I need to know the wiring configuration of the Red/Green Mimic LEDs - So I get back to my original questions...

Looking at the three wires attached to the Mimic Red/Green LEDs:
Is the Centre wire the "common" with red on one side and green on the other?  Yes and the paired outputs are "Handed", so you get opposite colours from each LED pair.
Is the Centre wire the Positive or negative?  I'm not sure on this one, sorry, I may have missed it, but haven't seen anything in the manual.
Does the Mimic Red/Green LED contain its own resistor or do I have to add one?   Yes, the board delivers LED level supply.
If I need to add a resistor, is a 10k resistor correct to balance brightness with the Green LEDs driven by the Mimic board?   I was happy with the levels of red and green, but others may like them slightly differently.  

Regards
Robin


Regards
J
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AHJAY
The Alpha Mimic LEDs have TWO wires, not three

It will ONLY be three wires if you use TWO separate LEDs

Reverse polarity to change from red to green.

Ahjay
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Robin Sundt Echini
Thank you for that Ahjay.
Does the two-wire Mimic Red/Green already have a resistor in it, or do I need to add one to the circuit?
Robin
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AHJAY
Hello Robin

There are resistors BUT they are of course appropriate for the Mimic output voltage.... Therefore Yes, unless you are using  alow voltage source, add a resistor. Start with 1k to be safe. Depending on your regulated DC supply voltage, you can vary down a bit or up a lot depending on the illumination level wanted.

Ahjay
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Robin Sundt Echini
Thank you Ahjay. 
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