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Does anyone know the name of the DCC unit that allows your train to slow down and stop at a station, then after a few minutes starts off and does the same thing at the next station, and then repeats the whole process over and over again.
Puzzler..
 

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QUOTE (Puzzler @ 7 Jun 2008, 07:38) <{POST_SNAPBACK}>Does anyone know the name of the DCC unit that allows your train to slow down and stop at a station, then after a few minutes starts off and does the same thing at the next station, and then repeats the whole process over and over again.
Puzzler..

You may be thinking of asymmetric DCC which has been implemented by Lenz on their silver and gold decoders (so called ABC) and by Zimo on many of their chips. This brings a train to a halt in front of a red signal and will move off again when the signal changes. There are quite a number of implementation issues with it which I will not go into here. I have implemented the Zimo version of it for my main line signals and it can be made to work well.
 

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There are a number of ways to do this but, unless you are using some form of computer control you will need to section the track & use a braking module with a way to trigger it & time the sequence. This is the way we have automated using DCC with block systems & station stops & work with all decoders.

I'm not aware of many self contained unit that achieve this - I think that Viessmann produce one but AFAIK it will only works with decoders that support Lenz (asymmetrical) braking, so that rules out non-"european" brand decoders.

Hopefully Richard or someone will know of an easier way.
 

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QUOTE (BVM @ 7 Jun 2008, 08:13) <{POST_SNAPBACK}>You may be thinking of asymmetric DCC which has been implemented by Lenz on their silver and gold decoders (so called ABC) and by Zimo on many of their chips. This brings a train to a halt in front of a red signal and will move off again when the signal changes. There are quite a number of implementation issues with it which I will not go into here. I have implemented the Zimo version of it for my main line signals and it can be made to work well.

As you say it can get quite complicated although very effective, especially when used with decoders that use constant braking distance. The circuits that we used would work with either asymmetric DCC or with a braking generator.
 

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I'm Not an expert on these systems but I read about "utilizing Brake on DC " on the TCS website
It is very enlightening what you can do with this feature
there is a web link which explains different systems of control using this feature of the decoder
Timed stop at a station is just one of the controls that can be acheived ,quite a simple system

http://www.dccbitswitch.com/tcsbraking.htm
Hope this helps
Regards
Zmil
 

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Trax controls.com could have the very thing you are looking for.

Look under 'electronic modules'.

The 'Station Stop' module SSM-1 is £21.95

Alan B
 

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Discussion Starter · #7 ·
Sorry Alan..
the SSM-1 will only work with analogue dc.. Not dcc systems, as it's output is a varying dc voltage.
Puzzler

QUOTE (alanb @ 7 Jun 2008, 09:30) <{POST_SNAPBACK}>Trax controls.com could have the very thing you are looking for.

Look under 'electronic modules'.

The 'Station Stop' module SSM-1 is £21.95

Alan B
 

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Discussion Starter · #8 ·
I'm not sure I understand this? do TCS have a special decoder for this?
Puzzler..

QUOTE (zmil @ 7 Jun 2008, 09:19) <{POST_SNAPBACK}>I'm Not an expert on these systems but I read about "utilizing Brake on DC " on the TCS website
It is very enlightening what you can do with this feature
there is a web link which explains different systems of control using this feature of the decoder
Timed stop at a station is just one of the controls that can be acheived ,quite a simple system

http://www.dccbitswitch.com/tcsbraking.htm
Hope this helps
Regards
Zmil
 

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A lot of decoders have "brake on DC" which, if memory serves me correct will bring the locomotive to a controlled stop if DC is applied to the section the train is in - the DC has to have the polarity the "opposite" way to which the locomotive is running.
 

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QUOTE (Brian Considine @ 8 Jun 2008, 08:19) <{POST_SNAPBACK}>A lot of decoders have "brake on DC" which, if memory serves me correct will bring the locomotive to a controlled stop if DC is applied to the section the train is in - the DC has to have the polarity the "opposite" way to which the locomotive is running.

Again from memory (of college electronics and somewhat hazy) but is this a reverse polarity applied to the track and as such means no 'potential difference' and therefore no 'effective voltage' so bringing the loco to a halt .........................

or am I way off track ?
 

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QUOTE (Puzzler @ 8 Jun 2008, 14:30) <{POST_SNAPBACK}>I'm not sure I understand this? do TCS have a special decoder for this?
Puzzler..

Hi Puzzler
All the TCS decoders (T1's + M series) I have bought (2003 on) have the "brake on DC"
The other web site linked to TCS Web shows how to wire up a "block" for different control situations using this feature
looks a bit expensive US$89 for the timing control , but you also need a braking generator.
Richard could probably explain it better
Regards Zmil
 

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QUOTE (Basil @ 8 Jun 2008, 20:17) <{POST_SNAPBACK}>Again from memory (of college electronics and somewhat hazy) but is this a reverse polarity applied to the track and as such means no 'potential difference' and therefore no 'effective voltage' so bringing the loco to a halt .........................

or am I way off track ?

***Brake on DC is activated simply by turning off the ability to run on DC by changing CV29.

Your thought above is OK for DC running (althoughthere are simpler and better ways for auto slowing with DC too) - but not for this case - we are still talking DCC decoder after all.... So - It has nothing to do with applying voltages as you mention above, the presence of DC with DCC running turned off simply triggers a software command to slow the loco at the deceleration rate in CV3.

If it was a simple zero potential difference in voltage at the rails then smooth deceleration would not be possible.

The braking section must (a) have the loco entirely in it when its activated (I prefer to use an optical detector set a few inches inside the braking section to ensure this happens.) and (
have a DC voltage very close to the DCC rail voltage. The best way to achieve this is by rectifying the DCC signal with a bridge rectifier.

You should also set CV3 to a reasonable figure to achieve realistic slowing down and acceleration.

You may have to tweak the CV3 settings loco by loco initially but Brake on DC is entirely reliable with TCS and lenz decoders, however I've found that its a bit variable with digitrax and NCE

regards

Richard
 

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QUOTE (Richard Johnson @ 8 Jun 2008, 12:53) <{POST_SNAPBACK}>***Brake on DC is activated simply by turning off the ability to run on DC by changing CV29.

Your thought above is OK for DC running (althoughthere are simpler and better ways for auto slowing with DC too) - but not for this case - we are still talking DCC decoder after all.... So - It has nothing to do with applying voltages as you mention above, the presence of DC with DCC running turned off simply triggers a software command to slow the loco at the deceleration rate in CV3.

If it was a simple zero potential difference in voltage at the rails then smooth deceleration would not be possible.

The braking section must (a) have the loco entirely in it when its activated (I prefer to use an optical detector set a few inches inside the braking section to ensure this happens.) and (
have a DC voltage very close to the DCC rail voltage. The best way to achieve this is by rectifying the DCC signal with a bridge rectifier.

You should also set CV3 to a reasonable figure to achieve realistic slowing down and acceleration.

You may have to tweak the CV3 settings loco by loco initially but Brake on DC is entirely reliable with TCS and lenz decoders, however I've found that its a bit variable with digitrax and NCE

regards

Richard

Many thanks for your detailed reply. (Although I didn't start the topic). I haven't yet set up any of my loocs on dcc but have all the bits and pieces (Select Controller and a few Hornby decoders and bachmann). Have to wait until I get some time.

However, surfing this forum's topics is a great way to learn some of the basics and the links are excellent

Great forum
 
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