Junctionmad

Nobody forces you to read it so stop whinging

yes but the points is the computation for LEDS is simple the voltage dropped across the series resistor divided by the set current , NO laws , algebra etc if you can use a calculator you can get the resistor needed . ie Green led , 10V supply ( 10-2.5)/0.005 is no more difficult then that modern red green blue yellow leds will run down to 1mA these days and upto about 30mA, ( many will survive 60mA) 5mA is a good starting point, white leds are slightly different heres a quick summary of the major types

looking at the layout measuring video its unclear how many magnets are being used . It does seem that the loco can establish patterns upto 2 metre away but the recommended spacing is 20 - 100cm Hence I think ill modify my previous statements , It is capable of establishing multiple position detections , how many is not clear , if you look at the track measuring video , you can see that you use a given loco to "walk " the track on the mimic panel . measuring each section . again whether this is by BEMF sensing or multiple magnetic field sensing is not clear . Hence the system is more capable then a single point spot detection again its not clear if the positioning is continuous or a series of discrete points whats clear is that with magnets min 20-100cm apart that's a lot of reference points on a layout with any sort of complicated track . which suggests that a near real time continuous update of position is possible

I dont think so , as the manual mentions that you cant have too many close together , so it remains an issue whether complicated trackwork can be handled secondly the position is indicated by you the user. What happens is you place the magnets and then position the train within the magnetic filed and give the tracker the pattern ID number , ie position A, it then memories the flux/field orientation patterns from magnets it can sense and applies your pattern ID to that pattern . Each time it detects that pattern it tells the RailMagic box "hello 'Im at pattern ID # position" The BEMF is simply used instead of commanded speed profiling ( TC & iTrain ) as as means of then estimating run distance from a known point . This is used to effect a slowdown and stop , but then TC does that to what's clear is there is no continuous position update process , That requires triangulation , each "spot" detection point is logged by you and a calibration is performed to acquire the calibration at that "spot "

which is the same for every spot detection system linked back to a computer , ie TrainController etc , nothing new there

We need to apply Railmagic logic , instead of scrolling the pages it would be better to display all pages and move the phone around the room in a augmented reality situation

My own view is that a Railmagic spot detector system that outputted digital outputs that could be therefore feedback into iTrain , TrainController and jmri would actually be useful. I simply don’t buy the fact that this “ guy” in his bedroom is going to duplicate a detector system , the functionality of TrainController and produce a sound based DCC decoder to boot. That’s replicating the output of 3-4 established companies. cant see that happening

The position data doesn’t go by loconet. His system includes a throttle capability whereby control is done using your existing command station that needs a link to the command station

True. However BEMF sensing has some advantages over simple speed profiling from commanded speed as it “ in theory” takes into account load changes etc. “. However in practice it can be very difficult to accurately characterise the relationship between actual motor speed and bemf

Note the reason he’s doing his own decoder and has issues with BEMF in other decoders is that to measure BEMF he needs a “ quiet “ period in the motor drive waveform to sense accurate bemf. He may be finding that difficult to achieve.

The net effect of whether you simply do speed profiling , ie the relationship between commanded speed and motor speed , or whether you use BEMF and equally a speed profile calibration to relate BEMF to speed over the ground is somewhat a moot point given fixed gearing both derive the same information ie an estimate of distance covered. Both are “ estimates” neither is actually doing direct measurements ( which a continuous positioning system could do)

I think all Railmagic does is spot detection , It does not Re compute position as it moves based on triangulation , it merely report a spot position reached and used BEMF dead reckoning in between “ spot “ detection You can do exactly the same thing with lineside spot detectors and Railcom speed feedback. ( which is actually independent of BEMF and hence much more accurate ) Railmagic still needs loco speed profiling because you have to relate BEMF levels to actual forward movement. all in all it’s a spot detection system at heart.

Well it’s all speculation until it’s confirmed. But based on reading the manual it’s not capable of triangulation all its doing is “ remembering a flux or field orientation pattern at a known point “ when it sees that “ pattern “ again the tracker in the loco reports it’s at the known point via the DCC link which is detected by the Railmagic box

Presumably to allow throttle control via the command station , he’s not proposing to override the command station DCC

Nick. Continuous position updating would be a game changer. But it looks like Railmagic doesn’t do this. It seems to build a pattern of the fields at a specific series of known points on the track. It then uses BEMF to essentially dead reckon from that known point Given that’s seems to be the case. This is essentially just another spot detector system. It suffers from all the issues of spot detection ( ie block occupancy is hard to do , what about rolling stock in the section etc )

At present Railmagic is a closed shop system. Ie you need all his software which essentially is a replacement for TrainController or iTrain. Given it will take several years to rival the features of these packages , it might have been better to design a system that could have been interfaced to these types of control solutions. given most proper DCC layouts are wired with track droppers , adding spot or section detectors is a simple addition , so the claimed advantages of Railmagic in using magnets are not going to transpire in real situations , moreover the disadvantages of adding an additional circuit board in the loco are very real and present a significant difficulty.

We run at 8A on the O gauge single booster

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Surely field orientation would be modified by the presence of ferrous metals , other trains , etc. If it can measure multiple field orientations it should be capable of continuous position calculations and would not need BEMF dead reckoning

I think he doesn’t understand the hobby at all quite frankly

I had a copy of the above somewhere and icant find it , has anyone a drawings of a suitable roller gauge thanks dave

Given the complexity of resolving different magnetic flux densities , the system must struggle to scale up to large layouts with many magnets as the patterns could be very difficult to resolve , then you add the effects of external magnets , other ferrous objects on the layout ( for example a TMD , which lots of locos sitting together , or an O gauge train of 6 metal carriages passing. Hmmmm

As I said it’s a spot detector followed by dead reckoning , this is exactly what TrainController , iTrain do. In these cases they can’t sense BEMF so they use a predetermined speed profile but the end result remains a dead reckoning system. using BEMF is fraught with issues, ie gradients between magnets , friction slowdowns. Heavy versus light loaded trains , wheel slip It’s a complicated spot detection system that’s all i think on reflection its fairly easy to understand the basic principles given what’s written in Railmagics manual. the advantage of Railmagic is you can implement multiple spot detectors without baseboard wiring but this is balanced by having to retrofit all locos with an additional module and the imposition of limits on the DCC configuration I think I end up with the baseboard wiring !!

By the way. The reason he has issues with multiple boosters is he must intercept the DCC signal between the track and the booster not only to inject commands ( using a reserved loco long address ) he must also receive the communications from the loco mounted Railmagic “ tracker “. Hence of the loco shorts two boosters he suddenly has a loco sending pattern IDs to two listeners. I suspect this system doesn’t scale well at all. ( It’s unclear how it handle say a 4 track main line or a complex station throat

Any spot detection system can claim “ millimetre precision , after all the spot detector is fixed. Once tripped further calculations rely on “ dead reckoning “ ie calibrated loco response to DCC speed commands , which Railmagic also needs. in one fell swoop he’s invented …..iTrain Only difference is track side spot detectors force the installation of wiring to each spot detector but the loco doesn’t require much of any modification railmagic merely swops that complexity of baseboard wiring for the issue of fitting another module in the loco and then modified the DCC signal to get the tag number ( in this case a magnetic pattern ID) back to its control station( which is why he currently needs a full train length of isolation between boosters ) Given the limit of 16 locos I suspect he’s modifying the DCc idle packets to return pattern ID info to his “ trainiac” ( this guy needs to get out more ! ) to many active locos would prevent him from getting enough idle times to transmit the ID info. Really he’s bending the DCC spec and that’s not good ( the same can be said of Zimos HULU protocol which modified the DCC preamble sequence ) other then curiosity value I don’t see any advantages and I see several disadvantages.