# LGB 2080S need info



## Greg65 (Jul 30, 2011)

Hi, I have inherited an LGB 2080S that is about 30 years old. I have been looking for a manual and have found a couple, but none have told me what this is. It is a grey plastic block behind the fire box. It has 3 pins with wires attached and V30 C75 A2 ~ K2 + - printed on it.
It appears to be the only electronic part except for wires in the train.


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## NavyTech (Aug 2, 2008)

I too have come across one of these and looking for a replacement for it. did you ever find out what it was for or is?


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## alecescolme (Dec 20, 2010)

Bi-directional lighting maybe? I had one in a power-tender that sound like what you describe, it was used for the bi-directional lighting circuit. 

Alec


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## krs (Feb 29, 2008)

Posted By Greg65 on 30 Jul 2011 01:00 AM 
Hi, I have inherited an LGB 2080S that is about 30 years old. I have been looking for a manual and have found a couple, but none have told me what this is. It is a grey plastic block behind the fire box. It has 3 pins with wires attached and V30 C75 A2 ~ K2 + - printed on it.
It appears to be the only electronic part except for wires in the train. 


Anyone hace a picture they can post?

From the symbols on it,
~ and + -
it sounds like a moulded diode bridge, ~ is the AC input and + and - are the DC outputs, but there would be four connections, not three.

Knut


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## Dick Friedman (Aug 19, 2008)

Maybe where this thing attaches to the engine body is the ground. It could be that it takes variable dc (hence the ~ symbol) from the track and converts it to unidirectional dc for leds or some other kind of diode.


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## krs (Feb 29, 2008)

Did a bit more digging. 

The same question came up back in 2010 on G Scale Central but the whole G Scale Central post is gone 

Google shows this: 

Chipping old locos (again!)... LGB 2073... - G Scale Central 
www.gscalecentral.co.uk › All Forums › [Power & Sound]Cached 
13 posts - 3 authors - 15 Jun 2010 
... 10mm square with three terminals, the block is marked: V30, C75, ... to what it is - I'm assuming it's a diode setup for the directional lighting. 

If there are really only three leads then I would assume it's a dual diode in a single moulded package, possibly a set of Schottky diodes to keep the voltage drop low. 
Strange to have a ~ symbol on the package but then this was 30 years ago. 
Best way to determine what it is (if a photograph gives no hint) is to trace out the wiring and see where these three leads connect.


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## TonyWalsham (Jan 2, 2008)

Any chance the pic could be posted in the message please and not as an avatar? Then we might be able to actually see what it is.


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## krs (Feb 29, 2008)

Tony, I never noticed there was a tiny picture as an avatar in the original post. 

As you said, a proper picture might help - preferably a few from different angles. 

Best wishes, 

Knut


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## TheRoundHouseRnR (Jul 15, 2012)

I'm new to this forum , saw this post and figured i would jump in. The " grey block" being descirbed is for directional lighting. Don't want to say that for 100% without seeing pictures as others mentioned but i am fairly certain this is whats being described. I have worked on many ,many lgb locomotives .It basically acts as two diodes with the anode and cathode leads on one side of each tied together and the others left apart. All rolled up in one package. There is a common lead from one side of track power that runs to both the front and back lights. Then the other side is ran to the variable input side of the block ( ~). From there it is split to the positive(+) to the front light and negative(-) to the rear lights. ( could be negative to the front and positive to the back , you get the idea). 

For someone that is not familiar with basic circuits. The box senses the polarity of the rails and blocks voltage from the back lamp and lights the front lamp or vice versa. Diodes act as a gate and only let electrons flow one way. They also can be used for low voltage switching or signaling due to there voltage drop as krs has mentioned 

I am confused a little, as you say there is no other electronic parts in the engine. The 2080S should be a sound loco , thats what the S stands for. so there should be at least a sound board. Especially with the older units. They didn't use printed PC boards at that time which made the circuits kinda of bulky ( these are the boards where you would see large resistors, transistors , and other through hole mounted hardware. But you do mention except for wires inside the engine. So maybe you haven't had the loco apart or maybe i misinterpreted your post 

I hope my posting was helping and i look forward to sharing more information when i can. thanks Kyle


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## TheRoundHouseRnR (Jul 15, 2012)

Never realized this post is a year old. lol Hope it still helps out Kyle


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