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Dr_C

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Dr_C

296 posts

OK I’ve started to answer the track series resistance question, but would still welcome comments on how to test a track to ensure there are no singular points of electrical discontinuity.

 

Back to the point of track resistance, when I assemble a U shape of track consisting of three standard straights followed by four standard 45 degree turns followed by a further three standard straights the total series resistance of each rail is between 0.5 to 0.8 Ohms. Given there are ten track pieces in play I conclude that single rail track resistance is typically 50-80 mOhms/piece. This figure includes measurement of any contact resistance arising at the connection points too (for my circuit there were of course only nine connection points not ten!). Also I should mention this track is about 10-12 years old so values are likely to be lower for new out of the box track. I have to say I am a bit surprised how low these resistance values have come out - but still recognise that voltage drops will occur across long lengths of track when large currents are flowing - acknowledgment to Mr Ohm for his very excellent law.

 

Now back to putting theory into operational practice. How should we test compliance of our track layouts to ensure there are no ‘singular‘ electrical discontinuities?

Dr_C

296 posts

Hi Blagard-01,

I like your exemplification of your point around deliberate omission of linkages which is helpful. Also I like the equations you share which remind me of school physics exams. I’m keen to use these equations to model track resistance effects and, therefore, wonder weather you would be in a position please to share indicative numbers for track resistance, perhaps measured in Ohms/metre. I would like to calculate the likely loss of power which will result from the ’deliberate omission scenario’. Looking forward to hearing back on this. Many thanks.

Second question, if ‘omissions’ which lead to lack of continuity are a problem in layout design, how do you test to ensure they do not occur at track level? i.e. how do you test your track layouts to ensure they conform to your ’good’ design principle? I can appreciate that two or more discontinuities on the same track would be instantly apparent. But how do you test to ensure there are NO discontinuities anywhere on the track?

I would really welcome your thoughts please...

C

 

Dr_C

296 posts

I don't disagree with you - I am simply explaining why the circuit appears to be fully functional as per Josefs 3hours plus of reported game play. Of course the brown rails wI'll not have any internal electrical connection unless a jumper is fitted. However I would use the term 'sub optimal' rather than 'bad' to describe this approach to design. More generally, now the reported modification has been upgraded so the size of the dead spot has been increased to 15mm we have moved from 'unsafe' to 'safe' - which is good!

Dr_C

296 posts

Hi Josef, great you have lengthened the cut to 15mm.

 

1/ As mentioned earlier - I really like your idea of modifying the flexible pcv by decoupling from the locating tabs and then insulating the exposed part of the pcb - completely agree this is far better than 'snipping' .

2/ blagard-01 is of course incorrect to assert that you need a jumper to connect the brown tracks because you yourself have already confirmed the system functions with two modified curved lane changers.

I assume your configuration has the following:

1/ the track is in good condition therefore all track joining connections are good from an electrical point of view.

2/ each of the two curved lane changera have exits onto different lanes in effect you are only introducimg one electrical discontinuity per lane.

3/ you are makimg use of the fact that a scalextric lane is powered in BOTH circuit directions and therefore remains fully functional when a single electrical discontinuity is introduced.

Of course there would be problems if you introduced a third lane changer into the mix - and that would be the time to each for the brown wire!!!

Enjoy the two lane changers - and your new ARC PRO :-)

Dr_C

296 posts

Thanks Andy... agree with your assessment... but still thought it useful to share my 'hobbyist' experimentations :-)

 

C

Dr_C

296 posts

Hi edteach3r,

 

The images are now with admin and I hope will be posted later today.

 

Meanwhile, might still be useful to keep the option C in mind - still my preference although I'm fully aware that opinions differ on this subject :-)

 

C

Dr_C

296 posts

Please see diagram which clarifies how the rails are cut in two places to create a dead zone. A single cut would be unsafe and would drive the base into overload each time the brushes traverse the single gap. Using the two cuts approach, refitting the centre section is optional but please ensure there is at least a 1mm separation between the centre piece of rail and the sections either side.

Dr_C

296 posts

Hi Edteach3r, many thanks for your comments and interest in the curved lane changer modification for the 'floating' exit flipper/wedge variant.

This variant requires a side-by-side pair of double cuts. These cuts can be made at any point on the lane changimg lane. I’m sure opinions will differ but I choose to apply the modification immediately following the entry/input flipper/wedge. Also, I make the gap between the rails 12mm in the form of 1mm-10mm-1mm for gap then isolated section of rail then gap. If you run with longer pick-up brushes then 15mm gap would make sense. Photos shown next to help provide clarification (hopefully)...

C

 

 

 

 

 

Dr_C

296 posts

It would appear that the two microswitches on the underside of the ARC PRO power base can be used to change the channel used by the base unit for communicating with the wireless throttles. This suggests that four separate ARC PROs can be used at the same time in close proximity.

 

The default setting appears to match the fixed setting of the ARC AIR. This is when switches 1 and 2 are both in the OFF position.

 

From my brief trial yesterday, when I change the microswitches to a different configuration (i.e. different channel) I then need to re-register each controller as per normal following the instructions in the manual. Then all works perfectly fine!

 

So far I have tried with one ARC PRO and one ARC AIR (set to a different channel) and both appear to function fully and completely independently of each other.

 

Interesting?

 

C

Dr_C

296 posts

Hope it works for you! I am planning to switch the wires around sometime before the weekend so can take some pictures if that helps...

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