Question: chipping an old LGB railbus...?

Zerogee

Zerogee

Clencher's Bogleman
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Hi all, I know there is an old thread about DCC-chipping an LGB railbus, which is very useful, but it doesn't seem to cover one specific point - re-wiring the lights to the new decoder.
I have an old DC Wismar 'bus, the flat-end one without the engine bonnets, which I want to put a Massoth LS sound decoder in. Picking up the power and motor connections doesn't look too bad (though a little more complicated than anything with a "standard" LGB gearbox), but I'm slightly stumped on the lighting.....

The directional front and rear white and red bulbs are all fed through the PCB that surrounds the motor, and then the interior lights (and the front/rear "top" headlights) are powered from the steel "handrail" uprights which connect to the roof-mounted lighting PCB.

Does anyone who's actually done one of these happen to know (or even better, have pictures) of exactly how/where they made the new connections to make the lighting run correctly from a DCC decoder?

Any help would be greatly appreciated!

Jon.
 
Have you got a picture of your board?
The one I did was (I think) a later model..
Beware of the metal `springs` which return the bogies to centre.. If you lift / dislodge the board(s) these can move, and short-out on the underside of the circuit board..

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Hi Jon,

Did one of these ages ago. Used an XLS then! Had to put the XLS in the roof. The 4 vertical handrails take the lighting juice up for the compartment lighting. Used them to take track power up and motor power down. Have a pig nose one to do at some point - with a LS.

Will see if I have any photos about.
 
Mark: many thanks, any pics would be useful - I'm OK on the basic installation of the chip (though I'd be interested in your method as a comparison), what I'm specifically after is how to wire up the lights to the new decoder, especially the bulbs for the dual-colour head/taillights.....

PhilP: thanks, that looks like a much later model, I think the board in that one is a factory decoder - did you just have to add sound to that one? Thanks for the tip about the centering springs! I haven't stripped mine down yet, when I do I'll take some pics - I was asking the questions now so that I know what I need to do when the time comes to tackle it....

Jon.
 
Jon,
Yes I thought the one I did would be later..
Supposedly, just a 'S' decoder install, but the springs had come out of their holders, and blown the decoder.. - The board has to be left in to hold said springs down!
I had installed the 'S' card in the trailer, and then realised the driving car was behaving 'strangely'.. By the time I had twigged what / where the fault was, it was too late.
So, then had to shoehorn a motor decoder in the driving car as well.

In my case, there were four (black, as normal!) wires to the board from the roof / cab lights. Common, Cab A, cab B, and interior. Similarly the front / rear lights. NOTE: in my case, the white lights were bulbs, and the red LED's.

As the motor decoder fit was an 'extra' to the job, I did not photo-document it too well, I am afraid.

HTH,
PhilP.
 
Refer to page 6

http://www.gbdb.info/data/zeichnung/LGB/21650.pdf

From my rudimentary German translation the lights are directional feed from the PCB with direct feeds from the motor.

Best guess, is either dispense with the PCB and make direct connections to the decoder, OR, if the tracks on the PCB are wide enough to modify it so that the correct lighting arrangement coincides with functions from the decoder.
 
Thanks Arthur, I'd already got those LGB instructions, but they never show anything like a wiring diagram that might actually be useful! ;)
That particular one is also for a later MTS-chipped railbus, the early versions are a bit different, especially regarding the internal lights.

The problem is that I can't simply dump the PCB, because in these it forms part of the physical support for the motor as well as supplying the motor connections. Guess I'll have to try and trace the PCB tracks and see if I can figure out which goes where, that was what I had rather hoped someone had already done and could supply a photo or diagram showing which tracks to cut and where to solder the new wires!

Jon.
 
Jon,
I just lifted all the wires, and (more or less) started again..
If you are putting a decoder in, it is fairly trivial to connect the motor to it. The track power from the bogies, and to the two aux sockets is a continuity test for polarity..
If this is an old model, I guess the lights are fairly simple?? Again, lift the wires. Test with a bench supply, set to three volts, and a series resistor in case you find some LED's. Then either use resistors, or set the divider values to suit bulbs / LED's with current limiting resistors.
 
Jon, whilst the link maybe of use, a search of the site may well throw up something more useful.

http://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.buntbahn.de/modellbau/viewtopic.php%3Ft%3D2882&prev=search
 
Thanks again, Arthur - that DOES look very useful, and may well be just what I'm looking for! :)

Have bookmarked the page!

I'll have a good read through it (and try to figure out the questionable bits of the translation from German!), then compare it with mine when I strip it down.

Jon.
 
I did a couple of these oldies. One for me and one for Andy Rush. What I did for the lighting was to reuse the Board in the roof by isolating it from the Posts then cutting isolation Gaps for each set of lights. Thus feeding the new circuits with soldered wire from the lighting Wires of the decoder. Took a bit of scratching the Single Brain Cell as to where to cut the Copper Clad. If memory serves, one had a Massoth Chip the other an LGB one with an LGB Euro Sound Box shoehorned in the Cab. I have another old one to do on the shelf waiting to be done, addicted to these things!

Will try to get the one that I have out to take a pic of the Copper Clad mods for you.
Jond
 
Thanks, JonD! :)

I think I can probably puzzle out the upper PCB, though any pics or notes would help - but no-one seems to have mentioned the main body-mounted headlights and taillights, which change from white to red directionally.
I don't suppose you (or anyone else on here who has done one) remember one specific point: each head/tail light bulb assembly (which has one red and one white bulb, linked to the lights themselves by clear plastic lightguides) has a three-wire connection back to the main PCB the surrounds the motor; this connection has a green, a white and a brown wire. Do you recall, or did you note down, which of the wire colours goes to the WHITE bulb, which to the RED bulb, and which is the common return?

Another quick question to all: does the main PCB, the one that surrounds the motor, actually contribute to the physical location of the motor - ie: will the motor stay in place if the PCB is completely removed and discarded? I know that board carries the posts that connect (or press against) the motor terminals - but I don't know how much the board itself helps to keep the motor in position.....

Thanks,

Jon.
 
I can only say the later model has substantial bits of metal sticking up from the board to make contact with the motor.. This will help locate it, and stop it rotating. Though I think the lower plastic part presses no the motor to hold it in place as well.

You can see them on the left in the picture I posted.. motor contacts sit on the outside of these, and are quite tight.
 
[quote author=Zerogee link=topic=300523.msg339895#msg339895 date=1421227148]
Thanks, JonD!  :)

I think I can probably puzzle out the upper PCB, though any pics or notes would help - but no-one seems to have mentioned the main body-mounted headlights and taillights, which change from white to red directionally.
I don`t suppose you (or anyone else on here who has done one) remember one specific point: each head/tail light bulb assembly (which has one red and one white bulb, linked to the lights themselves by clear plastic lightguides) has a three-wire connection back to the main PCB the surrounds the motor; this connection has a green, a white and a brown wire. Do you recall, or did you note down, which of the wire colours goes to the WHITE bulb, which to the RED bulb, and which is the common return?

Another quick question to all: does the main PCB, the one that surrounds the motor, actually contribute to the physical location of the motor - ie: will the motor stay in place if the PCB is completely removed and discarded? I know that board carries the posts that connect (or press against) the motor terminals - but I don`t know how much the board itself helps to keep the motor in position.....

Thanks,

Jon.
[/quote]

Hi Jon,

Couldn`t find any pics from when I did the conversion the ones below were taken today as it is in bits waiting for me to refit the decoder.

The 3 wires (Green, Brown & White) for the lights also connect to the two round interconnect sockets (Green & Brown).  The Brown & White are used for the lights.  Brown is common and white is switched from the main board.  Two diodes are used for direction control on the little board.

I disconnected the lamps from the 3 wire cable and inserted a socket for the lamps.  The cable for this was run up through the end panel to the roof where it plugged into a new connection on the board in the roof.

Not sure if the board actually helps holding the motor in place but it does stop the metal springs that help centre the axles from dropping out!  I kept it there and modified it a little after taking all of the components off (except the transistors/regulators in the 4 corners that are used for fixing).

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That's a great help, Mark, thanks! :)

So the green wire to the small lighting boards is actually only for the aux power socket, which I won't need.... I'm thinking the simplest way might be to remove the diodes from these boards, then resolder the wires to the PCB tracks so that one is for the white bulb, one for the red bulb, and one for a common return; then just make the necessary connections to the decoder such that when the white lights at one end are on, the red are on at the other end, and vice-versa.... time to sketch out a wiring diagram I think! ;)

Jon.
 
Hi Z, had a look today but it looks like a memory failure, it was the oldie that I did was for Andy and that has gone now. Mine are all newer, the Old one that I have needs to be chipped up.

So what I remember doing was to Isolate all the White Bulbs at each end, feeding them from the Fore and Back Chip Lighting Circuit. The Red at each end was fed by a separate set of wires that passed from each end. I think that I also did some Technical Isolating of these on the copper clad Circuit Board. This in effect lights up the 4 bulbs as required. Quite an easy fix once I got my head round the problem.

Hope this helps.
Jond
 
I think I get what you mean, JonD, basically you connected each red bulb in parallel with the white bulb at the OPPOSITE end of the 'bus, yes?

What I had thought of doing, if I can describe it in a way that makes any sense, is to re-use the two runs of green/white/brown wires that are already in place, but disconnecting them all from the central PCB. At one end I'd use the white wire as a common return for both bulbs, then feed the white bulb with the green wire, and the red bulb from the brown wire. At t'other end (eee, I suddenly went all Northern there for no apparent reason...) I would swap over the green and brown to the respective bulbs (brown for white bulb, green for red). Now, in the middle, each pair of white, green and brown wires would be spliced and connected to the three feeds (Vor, Hintern and common) from the decoder.

That should take care of the main head/tail lamps, as far as I can see..... for the overhead lights, I'm tempted to still keep all four steel handrail posts as electrical feeds - giving me one common return, one for the interior lights (the central bulbs), and one each for the feeds to the combined directional cab light and headlight at each end......? Or would it be better to forget the handrail posts and simply use a single four-strand ribbon cable from the top to the bottom...?

Still not 100% sure where to put the decoder (an LS) or the speaker.... floor of passenger compartment or in the roof?

Jon.
 
Just a few pis to show what I have done. My preferred method these days is to mount the Chip on the Roof with 4 Wires to it from the Motor Area. These are passed through a Black Drinking Straw in the Drivers Cab to disguise them. Straw liberated from a Pub. Then I use varying sheeting to hide the Chip and in one case a Speaker too. I have on occasion put the Speaker in the Cab and one of the pics shows this. In short there is no right or wrong way, what works best for you.

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The White Roof Sheet is an LGB Euro Diesel Sound Unit, the rest being Anteater. As my lights are on all the time on some of them, I think that I have fed them from the Permanent Low Volt DC Lighting from each Chip. Letting the Diodes in the Roof Board do its thing. But as these were all done some time ago, memory as said fails and as the Ties are all done to the Guard Rails I am a bit reluctant to pull them apart.
JonD
 
Thanks, JonD, all useful! When I get to doing mine I'll try to photo-document the process and then write it up here.

Particularly like the idea of the black straw as a wiring conduit....

Any other ideas, pics or contributions welcome! :)

Jon.
 
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