Mister Rusty
Ahjay advocates the fitting of incandescent12v. 21w car bulbs in series with the frog wire.
Here is my take on the installation
15544533190166213195819505628098.jpg  Whilst the bulbs could be simply soldered in place and dangle, l have gone this route to enable high-serviceability when exhibiting.

The layout is too short to have switched protection by an isolated section of rail, especially when a Beyer Garrett is lurking around, let alone dmu's.
The bulb-holders were less than £3.00 each off you know where, the bulbs under £3.00 for 10, same source. 
Cheaper than wearing out decoders.
As l use the layout as a teaching aid to give anyone a chance to drive DCC, "spads" often occur, especially with inertia being demonstrated..

Back to the rebuild.
Pete

If you're going to do it, do it right.
[ but don't count the rivets 😜 ]
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robertdcc
Hi!  There is something wrong with the picture - I can't get it to open any which way (phone, laptop, via the website)!  Please can you post it again.

Thanks

Robert
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Mister Rusty
Hi  Robert
it opens fine for me.
Will send again, though

15544623267234921625476379717786.jpg  should be just above.
Pete

If you're going to do it, do it right.
[ but don't count the rivets 😜 ]
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Bunkerbarge
It works OK for me Robert, are you able to view it through a different browser or on an alternative machine?
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robertdcc
Thanks for uploading again!  The new one opens up fine (Chrome browser, Windows 10 Home), the original one still doesn't!  Same in Edge and Internet Explorer.  And the original doesn't come up on my iphone either.  Very strange.

Anyway, I can now see exactly what you have done thank you.

Robert
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Iain Morrison wimorrison
wouldn't it be more effective to have 2 busses, one for the track and one for the point motors and protect the track with a cut-out device? That way you could still change the points when someone causes a short and the layout would start again instantly the short was removed (i.e. changing the point direction).

as for price with an MERG DCO costing £10 or an NCE EB1 @ ~£25 there isn't a cost saving in using bulbs in this manner.

Just a suggestion, it would also demonstrate 'best' practice  😉
Iain Morrison
Modelling h0e using Z21 with iTrain automation and Railcom
There are also unknown unknowns – the ones we don't know we don't know
http://www.wimorrison.co.uk
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Mister Rusty
HI Iain,
Thank you, l shall investigate.
Iain , thank you for your advice, it is really appreciated, honestly.
I follow what you are saying, and accept what  you suggest.
However, I set out on a course to have no wires running to and fro under the layout, having the minimal necessary, certainly no bus, definitely not 2.
Merg layouts always have too much wire for me; looking at Kineton by Leamington MRC, they display it with mirrors to show the complexity, whilst neat,
for what purpose? Computer control? Or, look at us, aren't we clever?
This approach to layout control has put off a lot of potential new modellers who often say ''I thought DCC was simple.''
We all know that it is , IN PRINCIPLE.
However, application can be different.
Not my scene, I wish to drive my locos, etc.
Also, there is no bus, deliberately. The layout is wired to easily accept one if l so wish, and would take just over an hour to add. Seriously.
It is a learning curve for me to just what is necessary and what is not. I cannot accept anything, unless l have proven it to myself. Always been that way.
As l have quoted elsewhere '' Why? is a most powerful word''. It has stood me well in various hobbies, currently having built a globally unbeaten 1300cc Civic, 15.97 secs @ 83.13mph for the quarter, using all standard Honda parts, just changed bits from different models. After we set the record, l still had people telling me that the engine just would not run.
Sadly, it is a *********** when l cannot apply what l know has been proven by others, without having to prove it to myself first.
Mind, it also generates interesting different applications.
Anyone else use car trim adhesive [no. plate] foam tape as underlay?
Works a charm.
MERG  DCO,  NCE EB1, what language is that? 😳
Seriously, I am off to research them. Knowledge is all.
I can always use the light bulbs elsewhere, Christmas is coming.
The layout works perfectly well without the  bulb holders, they have been installed as a  precaution only.
As I use the handset for all functions, including accessories, l cannot see how one controller can operate 2 separate bus circuits, using iP digital motors fed from the track. The layout is 15' long, end-to-end, so roundy-round rules are not relevant really. also, it is not even long enough to allow my preferred point protection by an isolation rail, the length of the power footprint of a multiple unit in reverse before a frog, hence the bulbs and holders.
I do not want power districts, track sensors, or a computer isolating me from the pleasure of driving the power unit etc. especially when one area will be driven under '' Inglenook'' rules, whilst a passenger service is operated by another operator. This includes conflicting moves and is very entertaining, something that could not be done easily with analogue.
My knowledge of electronics is minimal, just about understanding what diodes, capacitors and resistors do. Capacitors make nice confetti, don't they?? 😊
Iain,
thanks again
Pete

If you're going to do it, do it right.
[ but don't count the rivets 😜 ]
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Iain Morrison wimorrison
Pete

i hear all your concerns and share your thought MERG - I even took them to task at one exhibition when they were scaring the pants of people with the complexity of their demo - I have seen aircraft that have simpler installations than they have for a model railway! - Not made by Boeing I hasten to add 🙂, I mention them only because their kit is cheap, but you do have to build it yourself.

having multiple busses has benefit - especially when isolating faults but they can increase complexity but with that complexity comes increased reliability. 

And none of what hat I am describing earlier has anything to do with computer control, it is simply a way of wiring it 🙂

iain 
Iain Morrison
Modelling h0e using Z21 with iTrain automation and Railcom
There are also unknown unknowns – the ones we don't know we don't know
http://www.wimorrison.co.uk
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Mister Rusty
Iain
Thanks
Pete

If you're going to do it, do it right.
[ but don't count the rivets 😜 ]
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AHJAY
The objective of the bulbs is to buffer the short in the first place. it supplements overload protection and prevents the system cut out in the first place.

When a system has a short in relation to any loco running a frog it takes several seconds for you to remove the problem and by then, many DCC systems have already made a dozen or two unnecessary attempts at a reset with commensurate voltage spikes.... every one of which is harmful in a way.

I have sat on both sides of the "Same or separated bus" discussion. I am currently less and less inclined to use separated power bus structures... and more and more inclined towards the prevention of problems via safety interlocking and other such things, as they take less effort and in fact do more good.

regards, Ahjay
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Mister Rusty
Ahjay
Sitting both sides of the fence?
😫WATCH OUT FOR THE SPIKES  😫 on top
All the best
Pete

If you're going to do it, do it right.
[ but don't count the rivets 😜 ]
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