Two standard decoders hotter than one large decoder?

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Sammler

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I'm planning on fitting a decoder (or two!) into a Ge 4/4 III and have just read that fitting 2 standard decoders into a 2 motor locomotive can sometimes cause one of the decoders to become very hot. Is this a common problem or just an isolated incident?

http://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.reutimann-ch.ch/digital.html&prev=search

Would it be better to fit one large decoder instead?
 
Personally I would recommend 1 Big Un, with two small ones there is an extra element of falling over. I did have one small un of two blow in my LGB Brown Mallet and it still has the slightly Melted Plastic to show for it. Not sure how much saving there is. But if you go Sound, a Large Massoth will come in cheeper than two LGB Decoders and a Sound Box.
JonD
 
I have tried to improve the translation, but GTranslate failed. So I'm pasting it here:

"The motor that runs faster (from manufacturing tolerances or for whatever reason) is slowed down because the engine does not move as fast. Therefore, the decoder tries to adjust the speed and increases power. This does not accelerate the engine, because the additional force of the faster the motor is braked by the slower motor that does not want to turn so fast. This will make it even harder for faster engine that gets more "steam", etc. In my opinion, the solution to operate two motors with two decoders is nonsense anyway, because you are trying to control a single system with two control circuits. That can not work."
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How old is the GE4/4 III?
Fitting two decoders is an old solution now. when decoders were not powerful enough. But if you have an older model the early LGB decoders may plug in.
I would suggest using a modern larger decoder such as the Massoth XL (or XLS if you want sound). This may require a bit if rewiring in the loco but thats not too difficult and advice can be gained here.
The description translation shown by Beddhist, above, is true with modern decoders that have constant speed control software but older decoders dont have this.
 
The other reason for fitting two decoders was to make the loco act more prototypically..
In a Mallet the front would break away if power was applied too quickly. - This could be simulated if two decoders were used, but the above does still stand.
 
PhilP said:
The other reason for fitting two decoders was to make the loco act more prototypically..
In a Mallet the front would break away if power was applied too quickly. - This could be simulated if two decoders were used, but the above does still stand.
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You'd have to run the two decoders on different addresses to simulate that though. Originally the locos with two operated as two individual units so one could stutter leaving the other spinning, we cross wired the track inputs so both decoders shared the input but don't do it with the motor outputs ;)
 
PaulRhB said:
You'd have to run the two decoders on different addresses to simulate that though. Originally the locos with two operated as two individual units so one could stutter leaving the other spinning, we cross wired the track inputs so both decoders shared the input but don't do it with the motor outputs ;)
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No, if you adjust either the first couple of volts-to speed-step settings.. Or the start-up delay on the rear decoder, you can achieve the same effect.. .. you would have turned off load-control (back emf) as well if you were after this amount of realism.
Probably fitted TWO sets of magnets / axles for 'chuff' synchronisation .. .. .. Serious 'messing'! ::) ??? :o ;) ;)
 
It sounds like one big decoder is going to be the best option.

One thing the original article didn`t say is whether the 2 standard decoders were plugged into the original analogue board or connected directly to the motors.

From what I can tell, the 2 rows of motor/decoder pins on the analogue board are connected together and do not control the motors independently. This would explain why a single Massoth XL can control both motors using just one set of pins connected to the motors.

 

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  • LGB Ge 4 4 III Motor Pins & Massoth XL.jpg
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A while since I did one, so can not remember.. :(
Easy enough, try it and see if both motors run.. no harm will be done.
 
Sammler said:
It sounds like one big decoder is going to be the best option.

One thing the original article didn't say is whether the 2 standard decoders were plugged into the original analogue board or connected directly to the motors.

From what I can tell, the 2 rows of motor/decoder pins on the analogue board are connected together and do not control the motors independently. This would explain why a single Massoth XL can control both motors using just one set of pins connected to the motors.
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No, you DEFINITELY need to connect wires to BOTH sets of pins on the board, otherwise only one motor will run! You need to pair up the wires by colour and connect the two to each of the decoder screw terminals (eg: both greens into one motor terminal, both yellows into the other).

This thread might be of some use:
https://www.gscalecentral.net/digital-%28dcc%29/lgb-mallet-23851-massoth-decoder-fitting/

Jon.
 
PhilP said:
No, if you adjust either the first couple of volts-to speed-step settings.. Or the start-up delay on the rear decoder, you can achieve the same effect.. .. you would have turned off load-control (back emf) as well if you were after this amount of realism.
Probably fitted TWO sets of magnets / axles for 'chuff' synchronisation .. .. .. Serious 'messing'! ::) ??? :o ;) ;)
Click to expand...
Hmmm means it would always do it though which would irritate me ;)

Unless the new circuit boards are now cross wired on the two input side you will need to do it. They can't all be cross wired as otherwise with two fitted they would short out on the motor output with both fighting. I'd put money on needing to cross wire it ;)
 
Zerogee said:
No, you DEFINITELY need to connect wires to BOTH sets of pins on the board
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Thanks. Does anyone know if an ESU LokPilot XL V4.0 would be better than a Massoth eMotion XL (and is the the LokPilot supplied with wires)? I'm using an 18 volt power supply and have read that the Massoth decoders prefer 24 volts.
 
Nothing other than German instructions in with the LokPilot.
 
Depends what you mean by "better"?

Massoth decoders work just fine on 18 volts - that's what my NCE system runs on, and I have both Massoth and ESU decoders (and a few other brands).

As long as the voltage is comfortably above the minimum needed to power the decoder chips (usually around 7-8 volts ish) it will run.

If your loco is designed for / fitted with a 24 volt motor then obviously at 18v it'll run a little slower than its possible maximum speed regardless of which decoder brand you use. For me personally that's not an issue, I don't like to belt stuff round at full tilt anyway!

I like the ESU LokPilots (got 4 or 5 of the earlier model), they seem to have good smooth motor control. When I last bought some a few years ago they were cheaper than Massoth.

LokPilot V4 appears to be screw terminals like my earlier ones, so I doubt it comes with any wires.
http://www.esu.eu/en/products/lokpilot/lokpilot-xl-v40/
 
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