RobjUK

That sounds like the shield board has a resistor between the wiper and ground connections you are using; from the figures probably around a third the resistance of your pot. Try disconnecting the pot ground and see if you still get a varying input? If it does, though not very linear, if there is a resistor. If not it should just read full scale all the time. A fixed resistor on the input may be a stray pulldown or it could be intended to allow a two wire variable resistance input, or an active input from an opamp.

I noticed that the Railmatch green I'm using - and now the examples posted in thread, eg. and All look extremely close to "British Racing Green", as the examples in these photos: I think the difference in shade between those is down to overall lighting / image brightness & all the greens are very close? I wonder if someone actually copied that basic colour for railway use, it's been used in motor racing since the early 1900s...

All you need to do is set the maximum Back EMF voltage of the decoder to 4V, or the maximum speed to the level that gives 4V to the motor. Anything connected between the decoder and motor, other than possibly a low value resistor, will mess up the decoders ability to control the motor and properly measure the voltage / back emf from the motor. The input to the decoder can be normal DCC 12 - 15V range without any harm to the motor; just increase the controller speed very slowly while you are setting it up and monitor the motor voltage until you have a suitable maximum speed value set in the decoder.

It works fine with my O gauge stuff, even dual motor locos which are somewhat pushing the limits when used with the DCS51 alone. Anything using 12V (or lower) motors should be fine?

Just... NO You have a very fundamental misunderstanding of electricity and electronics. Connecting the secondaries of two different transformers is (normally) wrong. True. With such as American AC controllers, old Lionel stuff etc., then there is not much between the transformer and track, so that is rather dodgy and I can understand warnings relating to those AC track type systems. However with any DC or DCC controller, there is no direct connection between the transformer and the track outputs and nothing done to the track output can ever feed back to the mains side. [Designing electronics and industrial control systems for over 40 years].

Which do you have - DCS50, 51 or 52? If it's a 51, try setting option switch 39 to do a factory reset. On the 52, set option switch 40 to do the same thing. I have a DCS51, I can try the same CV commands with that for comparison if needed. Note that with mine the "three digit CV" limit is 255 - above that, I use JMRI Decoderpro connected to it via the digitrax USB interface (which I believe is built in to the DCS52).

That of course is the one item I did not look at - it's wheeltappers sound not legomanbiffo. Every other one has this: which is not an "online" service, exactly, unless someone pasted the wrong bit of text in...

Hi Charlie, what's happened to the "online reblow" service? I've seen mention of it on here & people being sent sound files, but all the items I can see on your site headed with that then say send in the decoder as the next paragraph?? eg. https://www.dckits-devideos.co.uk/index.php?route=product/product&product_id=84&search=reblow&page=2

Sorry, but to me that is the wrong approach. Basing it on the 5A controller or booster you mention, if that trips at eg. 7.5, then the cable resistance can drop over 12V at 7,5A and still cause a trip. That same cable resistance would be dropping 8V or more at the rated 5A load of the controller, which is crazy and would seriously mess up the operation of locomotives. The wiring needs to be much, much lower resistance than what's needed to simply cause a trip to ensure proper performance at full load - eg. aim for no more that 1 - 2V drop at maximum current, meaning less than a quarter the resistance of the "trip capable" cable, so at least four times the cross sectional area that you "trip test" would require.

That changes the whole context of the question! The first post implies that it worked with Marklin protocol (system) but not DCC.. Later on you kept saying it supports DCC, but you never never that it worked with DCC from the Marklin controller.

I totally agree, I've emphasised that myself before. The table post was purely to put across the fact the "hook up wire" is a general classification (mainly in the USA) and not any specific size or rating of wire.

"Hook up wire" is a nickname for fine stranded wire than can take regular flexing - it does not define the physical size or current ratings of such wire. That's why I do not like the phrase or use it except in replies to posts mentioning it; cable & wire references should always specify the cross sectional area or wire gauge, to be really useful. See the size and rating chart here, as an example - anything from half an amp rating to over 200A rating, just in that series..

A bit more done on the cab now, with the sides attached to the front and the handrails fitted. After I did that I realised the sides of the instrument panel were open & probably should not be! I found the two small triangular fillers in the etch sheets, but fitting and soldering them without other parts melting off was, well, interesting.. I've also started assembling the gearbox, which is a 40:1 ballrace type from Finney7. That went quite well until I tried to get the full axle assembly with all spacers in place to check the end play - one of the small etched spacers that fits between the gear and bearings went "ping" and has not been seen since. After some googling for appropriate spacers I've found that Tamiya make packs of bearing shims so have one of those on the way - it's got ten each 0.1, 0.2 and either 0.3 or 0.4mm so should come in useful for other axle spacing applications. A couple of tips for anyone else assembling one of these gearboxes. The various spacers that are supplied as part of the etch need cleaning up after cutting the tags that hold them in the etch. I found the easiest way to hold them was to put the shank of an appropriate size drill bit through the spacer, then it can be held with a finger underneath while filing the top. Also, the instructions say to use one small spacer on the motor shaft before the worm gear. The flat on the supplied Canon motor shaft starts too far away from the motor face for that to do any good and it needed all three spacers to give a good fit with no movement of the motor shaft.

Exactly - for hook-up wire; (except plain stranded copper is actually far more common than tinned). Internal equipment wiring & interconnection is a different application than power distribution. There are various classes of cable structure for different uses. Installation cables are very different from "hookup wire". There is nothing at all wrong with single core for fixed distribution whether it's fixed to a wall or a layout base, as long as it is not being regularly flexed. The feeds to that and the dropper connections are stranded so absorb any slight movements. It's a good practical and functional setup. [Designing & manufacturing industrial electronics control & power systems for over 40 years].

Look at the last diagram, posted by John ks The decoder typically switches the outputs to ground. The common to all the LEDs is a feed from the decoders internal positive supply; the blue connection in that diagram.

There is a possibly relevant bit on page 32 of an ESU manual, here: http://www.esu.eu/uploads/tx_esudownloads/00810-08526_ECoS_2_Handbuch_ESUKG_EN_User_manual_Edition_I_February_2010_eBook.pdf It's for a slightly different signal type, but yours may need the same procedure. In essence it says connect to the programming track output, turn the controller on then track power off and on again?? That seems to put the signal in an alternate mode to accept programming, if I'm interpreting it correctly.

See page 8 of the manual for that signal, here: https://static.maerklin.de/damcontent/67/79/6779d23d0cd1f0bb22b0f69319e1b9111537192029.pdf Do you have the address you are trying to use set on the DIP Switches? The instructions are very poor, but it seems you must set an address using the switches before you can do anything else with DCC operation. It also says "programming track only" for setup, implying you cannot have anything else connected to the programming system while configuring it.

Well, I've made a bit of progress on this one, but as always seems to happen, when I complete one stage I find another problem! I've finished painting the cab interior components and started assembling them - but I can only attach the front bulkhead to the floor & not the rear sections, as then it will not fit through the reinforcing angles in the bodyshell.. It looks like I will have to make up brackets and other supports to fit all the parts separately. I can't glue them together as they go in either, it all has to be removable to be able to paint the body and fit the windows. I've also discovered that if I fit one the seat to the floor, the drivers head barely reached the base of the windscreen! Looking at other peoples Deltic cab builds, it appears the prototype has a multi-level cab floor, which the cab kit I got does not have - I need to add a couple of platforms under the drivers seats. It's my first build; hopefully with any more that are this involved, I'll have a better idea of what is needed in advance & be able to plan parts a bit better. Whilst I'm trying to come up with appropriate attachments for the cab parts on this, I've dug out another brass kit I acquired a few years ago - a Judith Edge "Barclay 0-4-0" I picked up on ebay, an untouched kit. I started on it when I originally got it, then put it on one side waiting for (something) then work went crazy and I pretty much forgot about it... The first two photos are of the stage it was left at; the etched sheets and the underframe / buffer bars. Over the last week, I've built the footplate and separated & fettled some of the parts I will need next, plus doing some detail work and shaping of the various cab and body panels. I have just started assembling the cab today - no photos of that yet.

Unfortunately, no.. The type of fault did not mean I had to fully disassemble the controller and get to the inner circuit board. I was rather curious how the up/down button system worked, but I was not prepared to desolder things unnecessarily just to satisfy my curiosity. Mine varies between something like probably 40-50 for the main speakers (Goodmans Achromats) and JVC linear tracking record deck to current for the rear / surround speakers and active sub (B&K) and a Sony surround amp. "If it ain't broke, don't fix it!" Under 30s or teenagers may be confused by Record or LP, in the current fad they are called Vinyl - and typically played on unbelievably bad turntables / record decks with MP3 or bluetooth output - they just do not see the laughable side of that, the supposed and mostly fictional "quality" of LPs fed through lossy digital compression systems....

Hi, you are most welcome. They are an interesting little controller and amazingly good! RJ.

Any sensible person who wants things to work reliably. ... Running a total of under 200mA... Use whatever you like for your system, that's up to you - but giving bad advice to other people is not good.

As long as neither controller is connected to anything else - or the low voltage side of the transformers earthed - in any way, it should be OK. The critical part is that the only possible current path between the two controllers is through the track. eg. If they use metal enclosures and have an internal connection to the enclosure, the enclosures would have to be mounted on insulation rather than being possibly interconnected.

Cable resistance and voltage drops - the wires you suggest are far too thin for practical use to power a layout. And sorry, but to be blunt, if you think it's OK to use thinner wire at a higher current because the voltage is different or it's AC rather than DC, your understanding of basic electricity and electronics is somewhat lacking. Please read up on Ohms Law, as AndyID suggests.

The critical part with low voltage systems such as model railways is not the _current_ capability of interconnecting cables, it's the resistance per length and the voltage drops that resistance will cause when under load. A few volts drop on a mains power circuit is pretty meaningless - a few volts when you are starting with 12V or thereabouts is catastrophic! Also, voltage drops are far more critical with non-DCC systems as the control voltage regulation for speed has to run through the entire wiring and track system to get to the motor. With DCC, the regulation and speed control are performed within each locomotive - as long as the track voltage does not dip so low that the required motor voltage cannot be achieved, it can stand quite a variation with no ill effects.

SCART cables are definitely not suitable for any kind of power connection. They consist of many fine cores, mostly tiny coaxial cables & a multicore screened group in the top quality stuff. The photo below is the makeup of a good quality SCART cable; I just happen to have some bulk stuff kicking about. A bit blurry, getting a good focus was not easy but clear enough to make out the individual cores, I think. The "large" red/green/blue/yellow/white/black cores are each a tiny coaxial cable with a few strands of screen wrap and an extremely small centre core - it's most obvious in the green one. The overall cable is almost all insulation, due to the quantity of cores and their types. The connectors themselves could be used at up to a couple of amps per contact, possibly - but "D" connectors are smaller, cheaper and generally better quality. eg. The D15 type would be suitable, you can use several contacts in parallel for higher currents as needed and all the shells, latches or screwlocks etc. are readily available. eg. https://uk.rs-online.com/web/p/solder-d-sub-connectors/6740748/ https://uk.rs-online.com/web/p/solder-d-sub-connectors/6740767/