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Ian Wigglesworth
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Discussion Starter · #1 ·
I wish I had hear about the DCC Bit Switches before finishing my layout!!

DCC Bit Switch

Once I had seen the web site thought I'd have to give it a go.
Ordered the DC Generator Bit Switch and the Timed Station stop one, not cheap by any means but they do work!!



So the one with the Switch is the DC Generator, flick the switch to automatic and it will do it's stuff!
The larger one is the Timed station stop which comes with the two reed switches but you have to buy the magnets separately.
The section to be controlled has to be isolated (both rails) from the loop, as I have finished my layout I used a dremel cutting disc to cut through the rails at each end of the radius.
The reed switches are fairly big but can be hidden fairly easily and you could buy smaller ones.

The first thing to do is check you decoder settings, you have to alter CV29 to run on DCC only.
The TCS and Digitrax decoders work fine, the CT Elektronic doesn't support 'brake-on-dc' so you need to check which decoders you are using.

I have placed a magnet inside the front of the first coach, when the loco comes round and makes the reed switch the loco will be brought to a halt using the settings in CV3 and 4 for acceleration and deceleration.
After a few secsonds pause(which can be adjusted from 0-120secs) the loco will accelerate away.

It takes a bit of planning and fore-thought but it's a great way to partially automate a layout and by adjusting the position of the magnet inside the coaches, wagons or tender you can run different trains all without using a PC or buying software, like a say the Bit-Switches are not cheap but they do work well, I'm well impressed with just this one!
On my permanent layout that I'm just about to start to build I will use these to control the two loops, each loop can have two locos on, running in and out of a station siding all automatically.

A quick video of it in action, so the loco is running so fast, but wanted to try and keep the video length as short as possible, it gives the idea though.



Hope it proves useful.

Cheers
 

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Paul Hamilton aka "Lancashire Fusilier"
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Thats a neat review Ian - cheers for that. Looks like it would be well useful for that 3rd track loop where you just want something running in the background while you shunt the yard for instance.
 

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I have been looking into but they seem expensive for what they are.
For instance looking at the generator module it mainly seems to consist of a full wave rectifier a capacitor a switch and a couple of terminals couldn't have cost more than a few quid to make.
Also who sells them in the UK
 

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Looks a useful bit of kit to me - yes, you can usually make these sort of modules yourself for less money, but not everyone has the expertise to do so, or even the time.

Thanks for the review.
 

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Ian Wigglesworth
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Discussion Starter · #6 ·
QUOTE (Vulcanbomber @ 6 Nov 2008, 09:05) <{POST_SNAPBACK}>I have been looking into but they seem expensive for what they are.
For instance looking at the generator module it mainly seems to consist of a full wave rectifier a capacitor a switch and a couple of terminals couldn't have cost more than a few quid to make.
Also who sells them in the UK

Agreed!!
They are expensive for what they are, but to buy the components and work it all out and build them, is too time consuming, for me anyway.
I wonder if it's worth asking Fred Huges(owner of the Bit-Switches) if he would consider supplying them as a kit which we can then build.
May save a few quid, the LDT kits are about £12 cheaper when you build them.

At present there are no UK suppliers, but as I'm going to buy more of these for my permanent layout I have asked Digitrains if they would stock them, as my order will be quite large.
I will keep you posted.

I still think it's a great way to automate part of a layout with out having to use a PC and software and all the block detectors, which would also cost a fair bit, admittedly the Bit-Switches wouldn't be as powerful as the PC and software though.

Cheers
 

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Dear All,

A similar device for this type of control is the MX9 from ZIMO. See here for a comprehensive manual with various examples of how it can be used. It has enough connections for 8 sections in one module, if I understand the documentation correctly, so it is quite cost effective. I have never used this myself, but plan to some time in the future. Of course, it requires decoders with the ZIMO HLU braking implemented to work as designed, but this includes ZIMO and CT Elektronic (and possibly others). With additional boards, you can run signals and occupancy indicator lights (on a control panel or signal diagram) from the MX9.
 

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Ian Wigglesworth
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750 Posts
QUOTE (John @ 6 Nov 2008, 13:59) <{POST_SNAPBACK}>Dear All,

A similar device for this type of control is the MX9 from ZIMO. See here for a comprehensive manual with various examples of how it can be used. It has enough connections for 8 sections in one module, if I understand the documentation correctly, so it is quite cost effective. I have never used this myself, but plan to some time in the future. Of course, it requires decoders with the ZIMO HLU braking implemented to work as designed, but this includes ZIMO and CT Elektronic (and possibly others). With additional boards, you can run signals and occupancy indicator lights (on a control panel or signal diagram) from the MX9.

Hells bells!!
That MX9v block control module..............£315.84
thats more than all of the Bit-Switches I will need to do my full layout, I also don't need to buy a Zimo controller or the Zimo decoders to get it all to work!
Ok it might have much more functionality but at a price, and if you want the bells and whistles(probably literally!) then thats even more money for extra plug in cards.
Not really similar at all, in operation or price.
You don't work for Zimo do you John?


Cheers
 

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Hi Ian

With the Bit Switches , Will it work with the Lenz decoders or is the 'Brake on DC' different to the Asymmetrical DCC ?
the Asymmetrical can be created with 5 diodes , 2 on one leg of the DCC feed for the block and 3 on the other. The cost of the DC generator by Bit Switch does seem a bit pricey but if it is simple and works and does the job reliably
Then its a good product

Regards Zmil
 

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QUOTE (zmil @ 7 Nov 2008, 09:56) <{POST_SNAPBACK}>Hi Ian

With the Bit Switches , Will it work with the Lenz decoders or is the 'Brake on DC' different to the Asymmetrical DCC ?
the Asymmetrical can be created with 5 diodes , 2 on one leg of the DCC feed for the block and 3 on the other. The cost of the DC generator by Bit Switch does seem a bit pricey but if it is simple and works and does the job reliably
Then its a good product

Regards Zmil

Made a mistake with this post , The Asymmetrical DCC Generator has 5 diodes but only on one leg of the DCC bus so you only Isolate the section for Braking on one rail

Regards Zmil
 

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Just another modeller
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QUOTE (zmil @ 7 Nov 2008, 10:35) <{POST_SNAPBACK}>Made a mistake with this post , The Asymmetrical DCC Generator has 5 diodes but only on one leg of the DCC bus so you only Isolate the section for Braking on one rail

Regards Zmil

***DCC-bitswitch creates modules modellers are happy to use and comfortable with - thats the whole point.

Most are not adventurous in any way when it comes to playing with electrickery. (More than 90% also never ever change any CV other than address in DCC for similar reasons)

In itself though, Brake on DC is dead easy to implement and has been in most quality decoders for many years - all TCS, ESU, Lenz, Zimo etc...

It only requires that the braking section be rectified to DC, and that the DC level is within 1 volt of the DCC voltage. It is actually incredibly easy to do providing a modeller bothers to read the decoder manuals and think it through.

There are two things to consider. The one that is seldom stated but essential is that the whole loco needs to be in the "slow and stop" section when its rectified, and the decoder needs to have the run on DC option turned off via CV29.

For smooth stopping, you also need to set both CV3 (accel) and CV4 (decel) momentum appropriately of course.
 

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QUOTE (Richard Johnson @ 7 Nov 2008, 03:11) <{POST_SNAPBACK}>There are two things to consider. The one that is seldom stated but essential is that the whole loco needs to be in the "slow and stop" section when its rectified,
I may be wrong on this but I understood that the whole train had to be in the section, especially if any of the coaches for example had pickups/metal wheels ?
 

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Ian Wigglesworth
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QUOTE (Brian Considine @ 7 Nov 2008, 09:10) <{POST_SNAPBACK}>I may be wrong on this but I understood that the whole train had to be in the section, especially if any of the coaches for example had pickups/metal wheels ?

Yes, that is correct.

The reed switch is positioned so that the whole train length is in the isolated section when it gets activated.
So I can run different length trains I have just moved the magnet inside the coaches to a different position so that the whole train length is still contained in the isolated section.

Basically when the reed switch is activated by the magnet the Bit Switch relay operates and puts DC onto the rails in the isolated section, hence the need for the whole train to be contained with in the section, after the timer has timed out DCC is returned to the rails and the train just resumes what it was doing.

The set-up I have shown is very simple, as it's just used as a standalone unit.
It starts to get a little more complicated when it's linked into the other Bit-Switches, such as the Spur or block section.
At least you can share the reed switches, so the activation reed switch to operate this section could be used as the release trigger for the previous section.

When I start on my permanent layout I will take photos and try and explain where all of the connections goto, it's more complicated but will allow two locos to run on one loop, with one loco entering into a siding and waiting there until an express train has passed by on the mainline which will release it.
Wiring diagram below.
I will fit three reed switches before the turnout T1 and T3 this will give me additonal control of which loco enters the station loop.
One of these will switch the point one way the other two will be in series to switch the point the other way.
I will need two magnets in the coaches at a set distance apart, so that these will activate the two reed switches connected in series.
This way only the train with the two magnets in that line up correctly with the reed switches will switch the point to take the station loop.
Well thats how it should work in theory!!!



This will involve lots of reed switches for activation of the points as well, so it will be reed switch and magnet city


One thing with the magnets being inside the coaches, it should make them less prone to being knocked off the tracks!!

Cheers
 

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Just another modeller
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QUOTE (wiggy25 @ 7 Nov 2008, 19:06) <{POST_SNAPBACK}>Yes, that is correct.

Actually that isn't correct at all - I do not "guess" these comments I make... I've been using brake on DC in many applications.

It is just the whole of the powered loco or the consist, and the rest of the train does not matter one little bit.

if you used conductive couplings between loco and rolling tock or had an MU set with linked power, then all items would have to be in the block.

The key is that a direct short of both rails cannot happen at the gap. To ensure this I actually make the gaps offset.... or, where the possibility of a longer than usual train of loco's exists or optical sensing isn't possible ( I dislike reed switches), I make TWO sections, with them both activated only as the loco enters the second section.

It works very reliably like this.

Richard
 

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Ian Wigglesworth
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QUOTE (Richard Johnson @ 7 Nov 2008, 12:35) <{POST_SNAPBACK}>Actually that isn't correct at all - I do not "guess" these comments I make... I've been using brake on DC in many applications.

Richard

Crikey Richard don't bite my head off!


I didn't say you guess about the comments you make!!
I know you have far more knowledge than me, I was only answering Brian from the instructions/information that I have read and received.

QUOTE if you used conductive couplings between loco and rolling stock or had an MU set with linked power, then all items would have to be in the block.

So it was a bit correct then
 

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Hmmmmm - Some time ago we automated an existing layout using DCC - setrack was used in some places so it made sense to cut the sections at the joins, so they were in line. In a couple of places we did indeed make the sections shorter than the longest trains in use & did suffer from some problems - making the sections to match the longest trains certainly elliminated these problems.
 

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QUOTE (Brian Considine @ 7 Nov 2008, 14:58) <{POST_SNAPBACK}>Hmmmmm - Some time ago we automated an existing layout using DCC - setrack was used in some places so it made sense to cut the sections at the joins, so they were in line. In a couple of places we did indeed make the sections shorter than the longest trains in use & did suffer from some problems - making the sections to match the longest trains certainly elliminated these problems.
I think I've had this dicussion with Richard before ;-) Maybe I'm still missing something, but...

If you draw out the schematic of a DC section fed via a bridge rectifier from the adjacent DCC section, shorting either isolation gap is equivalent to a short across one of the rectifier diodes and will short one phase of the DCC signal.

That's the theory, but the practice may be very different. To see a problem, there are a number of pre-requisites:
-You must have metal wheels.
-The wheels must be able to make contact with both sides of the isolation gap at the same time. This depends on how rigid the axles are mounted in the chassis and whether they can fall into the gap.
-The contact time must be long enough to trip the booster. This will vary between layouts and operating practice. Presumably the train is going reasonably fast before it enters the braking section, minimising any contact.

Another thing to watch out for is coach lighting picking up from both rails on both bogies, in which case the whole coach needs to be in the section before switching to DC.

Another issue is propelling stock or multiple units where the motor is not at the "front" of the train. The safest advice in this case is to plan for the whole train being in the braking section before activating brake on DC.

Andrew
 

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Hi All

I think staggering the isolation gap by about 2" would eliminate most of the problems

for instance with my coach lighting two wheels (on one side) on one bogie are one pickup and the opposite on the other
unless there is a problem with feeding the internal lighting power momentarily from both feeds (DCC and Rectified for the braking section)
causing the command station to trip.

I suppose it just a case of testing for your particular system and rolling stock
It would take a fair bit of tweeking to get the stopping distance correct for each Loco anyway

Regards Zmil
 

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QUOTE (wiggy25 @ 7 Nov 2008, 22:24) <{POST_SNAPBACK}>Crikey Richard don't bite my head off!


I didn't say you guess about the comments you make!!
I know you have far more knowledge than me, I was only answering Brian from the instructions/information that I have read and received.

So it was a bit correct then


***Did it read like a bite - sincerely sorry if it did, I certainly didn't intend it to.

Not correct that a whole train should be in the block, but correct in that the powered part/anything continuously powered should be. For example, a loco and coaches with metal wheels - only the loco matters as long as the primary gap is not shorted, hence recommending offsetting the gaps as the best way.

The problem with Brake on DC is that its been there in front of everyone inside every reasonable decoder since the DCC standards were made and yet its never really been properly explained....

I actually did a couple of diagrammes a while ago and passed them in front of a couple of the better known brand decoder designers and they agreed that they would work fine as shown, but had no explainaton as to why decoder instructions never explain it properly!

here is a basic diagramme that will mean the braking section is never shorted and also allows you to use an across the rails inductive or resistive detector.

Regards

Richard
 

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Just another modeller
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QUOTE (SPROGman @ 7 Nov 2008, 23:54) <{POST_SNAPBACK}>I think I've had this dicussion with Richard before ;-) Maybe I'm still missing something, but...

If you draw out the schematic of a DC section fed via a bridge rectifier from the adjacent DCC section, shorting either isolation gap is equivalent to a short across one of the rectifier diodes and will short one phase of the DCC signal.

That's the theory, but the practice may be very different. To see a problem, there are a number of pre-requisites:
-You must have metal wheels.
-The wheels must be able to make contact with both sides of the isolation gap at the same time. This depends on how rigid the axles are mounted in the chassis and whether they can fall into the gap.
-The contact time must be long enough to trip the booster. This will vary between layouts and operating practice. Presumably the train is going reasonably fast before it enters the braking section, minimising any contact.

Another thing to watch out for is coach lighting picking up from both rails on both bogies, in which case the whole coach needs to be in the section before switching to DC.

Another issue is propelling stock or multiple units where the motor is not at the "front" of the train. The safest advice in this case is to plan for the whole train being in the braking section before activating brake on DC.

Andrew

***Hi Andrew... Yes, we've discussed it before - the diagramme attached to my reply to Ian tells it better than my description. Its similar to the one I sent U last time, and it works 100% of the time.

The issue is bridging the gaps for the loco.... or the longest continuously powered item. As you say, a DMU / EMU with the power car at the back needs to be in section, but thats the same really in context as a consist etc.

A standard passenger train or goods train, only the loco matters.

IF You do not use TWO isolated sections, you can only use non track dependent detection/triggering. Hence my preference for the dual section method, with one as a buffer section.

Zmil: ONLY if the detection is far enough into the section for the whole loco.

Richard
 
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