Heljan 0 gauge Wiring...

Discussion in 'Resources' started by InvernessTMD, 12 April 2013.

  1. InvernessTMD

    InvernessTMD Western Thunderer

    The following has been taken from another (defunct) Forum to preserve it with their permission.

    A question was asked about fitting a Loksound XL chip into a Heljan Hymek (though is relevant to most of their 0 gauge locos so far). One suggestion was to mill the chassis to make it all fit properly.

    Someone else on a different thread went about replacing the HJ PCB with a replacement that kept the handy little plugs on the wiring and also meant the original PCB could be put back in at a later date.

    "I contacted Heljan by e-mail and received a very prompt reply from Kim Nannestad. He attached a diagram on how to modify the PCB, albeit for connecting a Lenz GoldMAXI decoder, but I’m sure we can translate it to a LoksoundXL:"

    Class 35_digital (Small).jpg

    Looking up the Lenz manual on their website, and comparing it with the LoksoundXL chip, I conclude the following:
    Noticing the long-white wire highlighted here, I emailed again to question this as it is not shown on the schematic diagram:

    Kim replied saying that “It is important that you follow the picture in stead of the drawing”, and e-mailed a close-up:
    I'm not sure about this white wire - it looks as though it is connected to the fan socket to me. Can anyone "read" this better than me?
    As requested, here are some photos of the Hymek “stripped bare”, (with the PCB removed)

    In_Bits (Small).jpg

    body (Small).jpg

    undernside (Small).jpg

    Bare_Bogie (Small).jpg

    tanks (Small).jpg
    Colin M likes this.
  2. InvernessTMD

    InvernessTMD Western Thunderer

    Here are the PCB mods, and then compared to a photo from Heljan. IMPORTANT!! Do the cuts as per the diagram from Heljan in my original post, but wire-up according to the photo, not the diagram! (Ignore the “Danish-welding” appearance!)

    PCB (Small).jpg

    Did some testing before committing myself further!:

    Testing (Small).jpg
    I thought about mounting the LoksoundXL decoder in the roof, but in the end decided to have the chassis milled to mount it beneath the Heljan pcb. Also had the fuel tank casting removed, as Dave did, to leave 1.5mm just to locate the tank

    Chassis_Milled (Small).jpg
    Mounted the decoder on 2 lengths of Plastruct section, making an opening for the wire to connect to the speaker in the tank, via the hole in the chassis block

    XL_with_mount (Small).jpg

    XL-Mounted1 (Small).jpg

    Enlarged the openings in the base of the tanks (to hopefully let-out more sound!). As Dave says, the speaker is a nice tight fit, but I epoxied the enclosure to the base of the chassis, to give a nice solid mounting.

    Enlarged the openings in the base of the tanks (to hopefully let-out more sound!). As Dave says, the speaker is a nice tight fit, but I epoxied the enclosure to the base of the chassis, to give a nice solid mounting.

    Speakerbox (Small).jpg

    Put everything together, connected the lights & the fan – it works!
    XL-Mounted2 (Small).jpg

    Just a few thoughts:

    1. I should have given more thought to the routing of the wires on the Heljan pcb with-respect to their connections to the Loksound Decoder – ie which end of the pcb they exit. I will probably rewire it ……..

    2. The fan is extremely noisy, and probably not worth the effort

    3. I may fit extra speakers, although the sound is quite powerful – I have CV63 set at 20 in my loft!

    4. I haven’t had time to work out a way to control the red-lights independently, so I can switch them on or off – any ideas?
    iploffy and Colin M like this.
  3. InvernessTMD

    InvernessTMD Western Thunderer

    Next one, the 'adaptor board'

    I have been over the past few months dipping in and out of detailing and converting both my Heljan locos (37 & 47) to DCC with Loksound XL boards, but what I didn't want to do was cut the original wiring or fiddle wih the Heljan PCB (just in case it ever needed to be put back to DC operation). I decided to make a replacement board that fits in the place of the original board but that can be piggybacked by the XL decoder board, I wanted all the connections to be "plugable" and this held me up trying to source plugs and sockets compatable with the Heljan board, anyhoo this past week I have finally been putting solder to board and came up with this setup, and amazingly enough it all worked first time!
    Oringinal Heljan board behind

    Piggybacked with the XL

    And installed

    I have yet to include a socket for the fan, thats the next step.

    I am happy with the result, I hate wires running all over the place with seemingly no order, this at least keeps things tidy.

    One odd thing I have noticed with the Loksound XL is a continous buzzing from the board, some component on the XL buzzes away quietly all the time, not sure if this is a fault or a "characteristic" as some manufacturers are happy to use as an explaination!

    Circuit Diagram;-
    heljan veroboard for MIGO forum.jpg (155.93 KiB) Viewed 2514 times

    Should be self evident what goes where I hope

    I chose different connections (and better) for the vero to decoder so as no way can they be muddled.

    Be careful with the orientation of the sockets, see the keyways in the diagram.

    You could put in a slightly higher rating resistor (I only had 470ohm to hand) but found that when the voltage of the decoder is "dimmed" (I use a value of 2) the LEDs are just perfect, and there is already a 330ohm resistor at the LED end of the Heljan wiring looms.

    I think thats all.........

    Oh yes, there are no long leads across as I used matrix board for the initial test, for the final boards I am using full stripboard, also there is no provision for the fan on the board presently (mainly becasue I have not yet worked out which function switch to use) but its will be just a matter of two sockets on a spare part of the board, one for the Heljan fan lead and the other to the chosen function output on the decoder.
    tomstaf, Colin M and BrushType4 like this.
  4. Colin M

    Colin M Western Thunderer

    These are by far the clearest instructions I've seen for fitting a neat Loksound conversion.

    I'm going to visit the RS website to stock up on plugs/sockets and give it a go.

    Nice one! Thanks.

  5. Phill Dyson

    Phill Dyson Western Thunderer

    Don't forget to post it here :thumbs:
    BrushType4 likes this.
  6. BrushType4

    BrushType4 Western Thunderer

    Did you ever do this?
  7. BrushType4

    BrushType4 Western Thunderer

    I've just ordered some RS bits to do the same. I can't find the spacers on the RS website. Any ideas what the rs no. or where they would be?
  8. Colin M

    Colin M Western Thunderer

    Sorry, not yet, but it's firmly on my 'to do' list!
  9. BrushType4

    BrushType4 Western Thunderer

    Ok, I've ordered enough bits to do at least two. Will be delivered Wednesday.
  10. Dog Star

    Dog Star Western Thunderer

    If you have done the conversion then please post some pictures.

    Thank you, Graham
    40126 likes this.
  11. Colin M

    Colin M Western Thunderer

    Haven't forgotten, but still not made time to progress this... :(
  12. TheSnapper

    TheSnapper Western Thunderer

    A couple of months ago, I was asked by a friend to install sound into his Heljan Hymek, and he asked if I could replicate my installation, done about 6 years ago, which is outlined above, in Posts #1 & 2..

    I would have preferred to try the method as described in Post #3 above but couldn’t source the Heljan-style connectors. So I decided to use the Heljan PCB, which I had pre-prepared for my Heljan Class47, together a Zimo MX695KV instead of a Loksound XL. This meant that I wouldn’t need to do any rewiring or fitting series resistors for the LED’s!

    I also wanted to use a Cliff Williams 35mm speaker, and the stay-alive Goldcap array, which came free with the decoder from Digitrains.

    I followed the same principle as before, and had the chassis milled, to be able to mount the decoder beneath the Heljan PCB.

    I configured the lights and fan, as described in my recent post here
    Hopefully the photos will speak for themselves:

    Hymek3 (Large).jpg
    ZiderHead, Ressaldar, SimonT and 3 others like this.