Power distance

[scott_efc]

I posted this in the help section although its probably much better off in here. Apologies if its still in the wrong place!

 

As part of my uni work i need to set up a track around the top of a few spaces in our studio however its quite a decent length and just wondering if i need to boost the power at all. The circuit would be around 76 feet long and i would just be using a bog standard dc horny controller and power set up. So simply would i need more than one power feed and if so how do i go about doing this?

 

Would really appreciate any help thankyou very much, Scott.

[Penlan]

....As part of my uni work i need .....its quite a decent length and just wondering if i need to boost the power at all. The circuit would be around 76 feet long and i would just be using a bog standard dc horny controller and power set up. So simply would i need more than one power feed and if so how do i go about doing this? ...

It occurs to me that the would i need more than one power feed and if so how do I go about doing this? element of this answer is part of the Uni. Work, it would have been in my day (50 years ago), and thus in the written part of the work you would explain your findings and what you did to resolve it, hopefully from first principles. If somebody does give you the advise sought here, can we presume your findings will include a phrase like - 'I posted a request on RMweb for help and I have applied the answers as follows.....'.

 

Of course I know an answer or two, but I thought about it and worked it out, and BTW the answers in the question.....

 

Penlan

[scott_efc]

It occurs to me that the would i need more than one power feed and if so how do I go about doing this? element of this answer is part of the Uni. Work, it would have been in my day (50 years ago), and thus in the written part of the work you would explain your findings and what you did to resolve it, hopefully from first principles. If somebody does give you the advise sought here, can we presume your findings will include a phrase like - 'I posted a request on RMweb for help and I have applied the answers as follows.....'.

 

Of course I know an answer or two, but I thought about it and worked it out, and BTW the answers in the question.....

 

Penlan

The subject i am studying is Fine Art so our work is less about proving how we come about things and more about justify what we are doing in the firstplace. We fill perhaps 5 or 6 120 page sketchbooks with written notes and research each semester and trust me the tutors really read very little of it when assesment time comes around. So if i was to explain how i got it to work, it would be more than sufficent to say that i asked the question on RMWEB and the answer i got was ....

[Penlan]

Ah, I see, I think I would have to mark a paper as 'showed ability to use resources available....' .

 

Over 70 odd feet, of I assume some form of RTR clip together track, I would expect some drop in voltage although if a circle, obviously the furthest point from the power clip would be 35'. This would be exagerated by any ill fitting fishplates/rail joiners and/or oxidisation in the connections - and these I would suggest would be your greatest problem, any ill fitting connection would escallate the losses the further any 'loco pickup' was from the one power supply point.

 

I would run seperate power clips spaced at about 10' intervals around the track, making sure the railconnectors between each piece of track is tight (pinch in with suitable pliers), the wiring from each power clip is taken back to a common source for connecting to the controller - and make sure they are all the correct way round, otherwise you will have a short circuit, thus use either two coloured wires, or a twin cable that has either a raised moulding or a coloured stripe to one of the wire coverings. I am assuming of course that whatever your trying to prove/analyse requires a constant power source.

 

Once all is wired up use a simple multimeter to check the voltage output at the controller is the same at each of the power clips, there will be a slight loss, but not significant enough if your Tutor is just going to breeze through the results.

 

This is where you will see reference in the description of layout wiring to Busbars and Droppers, the thick busbars carry the power round the underside of the layout baseboards and the droppers, normally two soldered to each rail, are connected to the busbars to ensure as much of the power as possible arrives at the rail without significant loss. The Busbars are thick(ish) wire so there is not any significant power loss, thin wire won't carry much power. The analogy is say the flow of water through different size pipes pipes.

 

As an old moaner, we had to be much more precise in our presentations/essays/projects etc., just for 'O' levels/National Certificate.

 

Although I have been a railway modeller for nearly 60 years, loss of voltage has been brought home to me through faulty earthing connections in 6volt systems on pre WW2 cars I tinker with - at the headlights we can often only have 4 volts arriving, which with 28watt bulb main beams............ the futures dim Thus we bypass earthing through the car body now by fitting two cables to everything, including the starter motor.

 

E.& O.E.

 

Penlan