Junctionmad

There are a fair number of inexpensive loconet modules etc.

Thanks Tim

What’s the vertical “ rod” running down out of shot behind the banner box ? Dave

Is that mechanical or electric , if mechanical was there a balance weight

My own interest is actually based on a project “ I’m supposed “ to be developing for a friends layout. , even if I’m snowed with other things I’m looking at deploying MERG CBUS alongside some custom modules to achieve this hence I’m interested in a realistic discussion , not an airy fairy “ micro do wonder “ or a discussion around deploying post office relays a reasonable discussion is useful , otherwise it descends onto speculative design theory , rather then practical Applications. DC based train identification and speed profiling is in practice too complex to achieve real useful results unlike others I actually contributed. a sketch of a digital superbloc solution that’s practical

These days you get an awful lot of “ simple logic “ ability in a $0.90 micro controller !

Warm dilute vinegar ,

Mrs ID is right , MarchLane brought it up first ( my emphasis ) . I mentioned that you have to link loco to its profile . I didnt suggest RFID until it was mentioned

Sorry to resurrect this thread , But " The signal Engineers post in 2015 I cant now locate that Appendix , any help much appreciated

It should be stated again. There is best practice and there is basic functionality DCC will work with a couple of wires to the track , electrofrogs will work straight out of the box etc my friend has a 16 x 8 OO complex layout on three levels. All run on DCC , with a few feeds to the track. best practice ,no , works , yes

Running alcohol is diluted IPA

Is there a source for these drawings ? regards

Thanks Clive

I still see several significant issues while it’s entirely possible to rely loco specific data from block to block , something at the start has to provide that initial data. ! secondly when people bandy about terms like RFID , they are clearly not aware of the issues. Merg members have done a huge amount of work in this area but the systems using commercially available tags and readers are not yet “mission capable “ because there are issues like speed of reading , antenna position /distance and multi track interference. these are not easily solved when I was in college , we cloned the term “ microprocessor do wonder “ to describe the situation where with a wave of the hand technical issues were bypassed there is already man years on implanting the basic digital super bloc , merely mind trying to make it loco specific I’m not decrying trans-ponding , but I know from my on experiments that the devil is very much in the detail in the same way mention was made of “ using CBUS “ etc. Right now CBUS for example has no means of transferring analog values without custom module software , doable ,yes , out of the box ,no

Knowing the BEMF is useless , because unless you have a relationship stored somewhere that relates a loco ID to the speed over the ground . this then means you need loco ID ie trains-ponding so that the block controller knows what loco it’s dealing with if you do that , you still don’t need BEMF , because you might as well store speed versus applied voltage for a given loco and simply look up the needed DC voltage for a given speed the alternative is a whole layout control system that knows where everything is and what everything is. Good luck with that in DC. the practicalities of implementing a solution in a DC layout means in reality you will simply have to accept you can’t profile locos no identify the specific loco in the block section . All you can do is ramp up and down the track voltage and the locos respond based on load and gear ratios

A decentralised systems is easier to manage , ie a digital Superbloc as to my knowledge no off the shelf " whole layout " automation is available for DC , so your very much into a roll your own A digital version of Superbloc would look something like this The disadvantages are common to all DC control systems, that is you have no knowledge of the relationship between the applied DC violate and the running speed . Sensing BEMF doesnt help , in order to have a relationship , you are into train identification , as you have to relate the train in the block with its DC characteristics . This is a whole big can of worms. Superbloc makes no attempt at that and in my view neither should you .

You can easily do what you are saying with a 5V digital pot chip , an amplifier to step up the voltage and a darlington pair . Equally you can use a H-Bridge and filter it to produce DC Its worth putting this question into the MERG forum as there are some current and recent projects to create distributed DC control systems. One of the issue with PWM is at teh boundary the loco may in effect join two H-bridges together in parallel , but these bridges are not synchronised and hence create shorts for one another . IN the MERG system this was solved by distributing a clock to keep all teh PWM synchronised A pure DC system is easier to manage in that respect

You can easily do what you are saying with a 5V digital pot chip , an amplifier to step up the voltage and a darlington pair . Equally you can use a H-Bridge and filter it to produce DC Its worth putting this question into the MERG forum as there are some current and recent projects to create distributed DC control systems. One of the issue with PWM is at teh boundary the loco may in effect join two H-bridges together in parallel , but these bridges are not synchronised and hence create shorts for one another . IN the MERG system this was solved by distributing a clock to keep all teh PWM synchronised A pure DC system is easier to manage in that respect

indeed, at high frequency it all looks like DC due to the inductance of the motor anyway

I know very little about " modern " signals , but I have to make a few O gauge simple 2 as[ect colour lights and GPLs for a new depot layout. The type of detailed info available for semaphores doesnt seem to be available for such signals. Most likely the standard SL35 filament head Im looking for a drawing of something like this , or at least the basic dimensions , a scaled photo. I gather there were different " back boxes" to these signals ( vertical and sloped ) etc . Also for the common Ground Position Indicator thanks for any help https://en.wikipedia.org/wiki/File:Two-aspect-signal_ES692.jpg

hS I meant some people dont like PWM, ie pulse width modulation of a pulse signal. So the alternative is a DC level control via series pass element , yes via a amplifier which could be driven in a number of ways from the PIC , R2R , DAC , or frequency to voltage etc.

The thread was originally about a pic version of MERGs superbloc . Superbloc is DC and each block section control feeds the next section with the DC control level being used in the current bloc. The idea being it sets the track voltage for the next section . The section can either accelerate or decelerate the loco from there. Superbloc has no idea what actual speed the loco is doing Duplicating suoerbloc is easy to do with a micro If you start getting into track detection , or trainsponding , you’d be better off going DCC dave

yes , but some people dont like PWM based drivers

has anyone got XtrackCad template for Marcway points etc thanks Dave

Ive used all three controllers. Id say each has its strong points and weak points The DR5000 is good value for what it says it can do, and its a good choice if you intend to use other modules in the range Teh Z21 is very flexible and has support for lots of busses , including a sniffer bus , its my preferred goto unit within the three mentioned ( there are aspects of the app I dont like ) The ECoS unit is very well built , buts its pricey and the haptic features get "old" fast . Its got a significant learning curve and is not a walk up and go controller I used Prodigy and NCE as well and would rate them behind the Z21 The drawback of the Z21 is there isn't a good non smartphone throttle choice , theWif MultiMaus is fairly awful and eats batteries All thre choices will run your layout , the choice is done to preference and cost