LGB #2051 'V51' "DB" decoder install

Tim Brien

Registered
At present I am preparing a LGB #2051 Euro diesel for a Massoth XLS. I have the underframe wired, but am perplexed by the lighting circuit. Either end of the body has a constant brightness 5 volt circuit board for headlights. Is it OK to use this board for decoder '+' power supply for the lights or will the components on the circuit board cause problems?
 
Not sure if it can be done but when i fitted the same chip to mine i just disposed of all the old stuff and glued in some white LED's and resitors.
 
Steve,
it is more convenient to leave the board in, if possible. I traced out the board and if I remove the 7805 component then I should be able to bridge out the input wires to feed direct to the lights. There will still however, be a few components left on the board like a capacitor and resistor to deal with. These would be in the bridged out 'reduced' voltage part of the circuitry and may or may not impact electrically. I would feed 5 volts direct from the decoder.
 
Not familiar with this particular loco, but if it were me I'd probably bypass the voltage regulator and wire my own resistor in series with each LED, calculated correctly for full track power. I'm not a big fan of relying on the decoder to reduce the output voltage on the function pin: it works great but what if you accidentally reset the decoder or fit a replacement without remembering to change the voltage CV? ** POP!!**
 
I have yet to get round to making a replacement lighting pcb fpr my V51, using Veroboard and LEDs.

Zerogee (Jon) has done one though, using the original lighting pcb,so it might be worth sending him a PM....
 
Here you go - this is how I did mine: first, take out the lighting boards and snip off (and discard) ALL the components on the except for the actual bulb holders. That should leave them looking like this:

752d88c299064a8ea24b56370b27884b.jpg


Now, on the actual circuit side of the board, unsolder the GREEN wire from its pad, and re-use some it to bridge across between the two points shown (you could actually solder it in several other positions instead, what you need to do is connect the BROWN wire's circuit track to the outermost track that runs around the top and sides of the board). Once you've done this, the existing brown and white leads become the two power wires for all the lights at that end of the loco, and you simply connect them to the relevant lighting terminals on the decoder.

257ff68b3ade4ddfaccee2c8f5087177.jpg



Here's the actual installation of the XLS, speaker and manual volume control pot.

a8f7a23dc2194cc9b4c8d49596d2bea1.jpg


It's very simple, and seems to work OK on mine - hope it helps.
Note that I chose to put new 24volt bulbs in my loco, but if you keep the old 5volt ones be sure to adjust the lighting voltage CV on the decoder BEFORE you apply track power!!

Jon.
 
Looking back in the archives, I realise that I've posted these pics and description before - here:
http://www.gscalecentral.net/m13785...e same question as Tim asked here! Jon.
 
Zerogee said:
Looking back in the archives, I realise that I've posted these pics and description before - here:
http://www.gscalecentral.net/m137856
.... in a thread that I started myself, after I asked basically the same question as Tim asked here!

Jon.
You are a man ahead of your time Jon!

Perhaps you have seen my thread on acquiring DCC knowledge and primers etc.. I feel that I will be giving you a call soon for some input when it is convenient with you.... I will soon be wiring up a USAT loco for DCC but also leaving the guts ready for switching back to full DC operation. I know that your experience would be more than valuable in this little project.
 
Happy to help if I can, Mike - give me a call when you're ready! What decoder are you putting in it?

Jon.
 
Hi Jon
It will be either a ESU LOksound or a Massoth XLS. I do have a lenz decoder but it is not a high power handling jobbie which is what USAT locos need. But first, before I start chipping the locos, I want to find out if my layout can handle a DCC system! My block wiring and powersupply cables may need a bit of reinforcing as DCC needs good low resistance trackage and wiring and I do have a few areas which could do with a check over.
I will also be installing two circuit isolation breakers that can bring in either DCC power or DC power so that the layout can operate both BUT not at the same time! This will allow me to operate the number of locos that I have which are not chipped. I know unchipped locos can be used on DCC butb as I have to run 'lash-ups' for the gradients, I will keep the two power systems in place so that the triple headers can run on pure DC until they are all chipped.
 
Bumping this tread again. Have this old LGB 2051 and I'd be interested in installing a decoder: what's a modern decoder that would work (either massoth or piko?) that could handle the two motors of this unit? Thanks!
 
Well, the Massoth XLS that I used works fine, Rob! If you follow the notes and pics above, the lighting boards are easy to modify. Or a Massoth XL if you don't want/need sound.
I haven't used a Piko decoder, though I think you'll find these are just "re-badged" Uhlenbrock units.
There are many other decoders that will work just as well - ESU, Zimo and such, I tend to use Massoth because I'm reasonably used to them but other people will all have their personal preferences.

If your 2051 has pre-D type gearboxes (3 pin rather than 4 pin) or the even older clamshell boxes, then you'll need to go into the gearbox units and do some re-wiring to make them DCC compatible before you start on the actual decoder install, but none of that is particularly difficult.

Jon.
 
Thanks for the feedback Jon, but I'm pretty sure it's a pre-D type gearbox as it's "Made in W. Germany" so pre 1989. So it may be a clamshell as well. Pretty comfortable with a soldering iron and screwdriver just concerned about me inflicting damage in the disassembly and reassembly of the gearbox.

Any step-by-step guides for rewiring these old 3-pin gearboxes to prep for DCC?

Also, Jon, I noticed the links you posted way back when referencing another similar post to the above don't work. Did they include any additional tips? Thanks all!
 
Thanks for the feedback Jon, but I'm pretty sure it's a pre-D type gearbox as it's "Made in W. Germany" so pre 1989. So it may be a clamshell as well. Pretty comfortable with a soldering iron and screwdriver just concerned about me inflicting damage in the disassembly and reassembly of the gearbox.

Any step-by-step guides for rewiring these old 3-pin gearboxes to prep for DCC?

Also, Jon, I noticed the links you posted way back when referencing another similar post to the above don't work. Did they include any additional tips? Thanks all!

If each gearbox has a split line down the centre of it when viewed from underneath, then it's a clamshell - if it has a one-piece baseplate then it's a "sandwich" box, and if it doesn't have the little embossed "D" on the baseplate then it's a pre-DCC 3-pin. The procedures for DCC-readying a 3-pin sandwich or a clamshell box are of course different. Making a 3-pin into a 4-pin is easy, you just need to isolate the "white" (WS) pin from the motor terminal that normally presses on it - usually by bending the motor terminal tab gently away from the pin and slipping some heatshrink over the pin to keep the two apart - then solder a new yellow wire directly to that motor terminal, bringing the new wire out through a small hole drilled in the gearbox top plate. This new yellow wire becomes your "4th pin", and you simply connect the decoder using the usual LGB brown/green/white/yellow colour coding.

For a clamshell box it's still quite easy - open up the gearbox after removing the wheels on one side (the side that has the screws which hold the gearbox halves together), and remove the motor. Attach new wires (yellow and green) directly to the motor terminals, either soldered or using push-on spades, then you need to isolate the motor terminal from the two vertical strips of brass that normally make press-contact with them; you can either leave the brass bus-bars as they are and insulate the motor terminals (and their new wires) from them with heatshrink, or (if you know you are never likely to want to convert the gearbox back to DC again) you can simply snip the vertical brass strips off with a pair of fine cutters. For the track power feeds (white and brown wires), these can be soldered onto any suitable point on the gearbox which connects to the brass bus-bars - usually there will be two little brass tabs visible on the top of the gearbox which are where the loco picks up lighting power, and these can be used for your brown and white power wires. Lead the new motor wires out through the top of the gearbox (file a slot for them if there isn't a suitable hole available), bundle them with the new power wires and thence to the decoder - job done!

Jon.
 
Thanks all. Sounds easy enough and a good evening project! Since this is a dual mother loc, do I just do these modifications 2x (one for each gearbox) and double up the wires into the decoder terminals from each gearbox/motor?
 
Thanks all. Sounds easy enough and a good evening project! Since this is a dual mother loc, do I just do these modifications 2x (one for each gearbox) and double up the wires into the decoder terminals from each gearbox/motor?

Correct..

Always worth checking with your meter, you have the same track connections with the same colour wire.. Before you connect them to the decoder. - Had a loco where the motor blocks had been put on as mirror images of each other. really confused me for a while, when the controller shutdown!
 
Thanks all. Sounds easy enough and a good evening project! Since this is a dual mother loc, do I just do these modifications 2x (one for each gearbox) and double up the wires into the decoder terminals from each gearbox/motor?

Yes, you need to convert each gearbox, then double-up the wires to the decoder - it's probably easier to run both sets of the wires to a 4-way choc block connector and then single wires from there to the decoder itself.
A good evening's work should see the job done, it's pretty straightforward once you look inside the gearboxes and figure out what goes where.
One note of caution - before you actually connect the decoder and put power through it, just check all your wiring with a meter to make sure there are no dead shorts where you've connected the two motor blocks together - you need to make sure that both brown wires are going to the same side pickups, and same with the white, and that both motors (green and yellow wires) will run in the same direction! ;)

Edit: PhilP posted the same thing about polarity checking while I was typing!

Jon.
 
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