NFWEM57

On 03/06/2023 at 10:30, Eveannessant said:

Hi Patrick, good of you to commit to posting a circuit diagram, thanks.

Below is the PCB schematic.  The inputs are wired to the board, blue, green (aux1) and purple (aux2) on the left. The yellow and white are connected to the left of the DuPont connectors.  The DuPont connectors are as follows:

• White/Orange, Yellow/Orange - Head Code Lights on chassis (LED)
• Dark Blue - Adjustable White Running Lights - Body Shell
• White/Yellow  - Body Shell
• Red - Switched Adjustable Red Running Lights - Body Shell
• Purple - Switched Adjustable Cab Light

The trimmer are 50K, all resistors are 1K.  Light yellow is top of PCB with components and where the track cuts are.  Dark  yellow is underside (mirror) to show where the cuts actually are.

My latest design only has one trimmer to provide a differential between white running lights and marker lights if they are fitted, otherwise it is not required.  Speaker, track supply and part of stay alive circuit mounted on PCB as well.  Same PCB footprint, 9 x 12.. Screw terminals used instead of DuPont.  Some components not fitted if they are not used, likewise unused screw terminals. 

I am trying to show the circuit with text but the writing keeps getting hidden, Will try again later.

11 hours ago, Eveannessant said:

I've always found Zimo decoders to be better than ESU,

I started out using LaisDCC but eventually settled on ESU for the Command Station and thus decoders.  Have never purchased Zimo but some of my Steam factory fitted DCC Sound may have them fitted.  I do have Hornby TTS for my HSTs and have added stay alive to them.  The latest version of my PCB includes speaker connections and most of the stay alive circuit in the same footprint PCB.  I am using 21 pin decoders almost every where in my diesel fleet, but only a few are sound.  My planned layout is a replica, in EM, of a western mainline country junction 1960s to 1980s so it is about watching the trains go by.  Basis of circuit for switchable red shown below.  Opto-coupler used is 817A, type into google and you will find it offered by many manufactures. For a dual variant search for MCT62.  I bought in bulk a while ago and they cost me £0.11 and £0.28 each respectively.  Post COVID, no idea of cost now..!

23 minutes ago, Eveannessant said:

A circuit diagram of the vero board components would be nice

Hi, Thank you for your comments.  Only one motor wired up.  I too have a few later Bachmann models but its would have been a pity to part with usable stock.   I have converted Hornby Class 35s, Class 37S and Class 47s from the 1980s in much the same way. I have a newer PCB which does not use trimmers but relies on the CV adjustments for brilliance; ESU decoders. I'll dig out the diagram for the circuits shown and upload here. Please give me a day or two as family events are occurring over the weekend...!  The integrated circuit is a dual opto-coupler which is used to convert the Aux 1 and Aux 2 current sinks to a power feed for the red running lights and the cab lights. Yellow and White then used as normal for both. 

I was using a wheel puller, might have another go using an alternate method but US wheels already purchased so may as well use them.  Below is my Mainline conversion, which I sold on a while back.  Direction sensitive cab lights (Aux2) and switchable red running lights (Aux1) both enabled by the lights function. 

Cab light off (left) and on (right)

I have 3 more to convert for sale with 8 pin decoder sockets and 3 more to convert to EM (for me) with 21 pin decoders, stay alive and a new PCB design which provides the same functionality described above.  Will be using ESU decoder so better motor control and tuning.  No need for light brilliance adjustments on the PCBs, all done using CVs in the decoder.

Patrick

This is a fascinating thread. I have a number of Mainline and Bachman models for conversion to EM gauge for a planned west country layout, US wheelsets (NS) and brass gears (for mainline) already procured.  Just acquired D835 Pegasus for renaming to D854 Tiger.  RTR whels are accurate shape wise but almost impossible to remove with out damage. Hence US wheel sets for EM.  In the past, have converted Mainline model to DCC 8 Pin and added running and cab lights.