Wiring and power questions

[Mil1ion]

What is the power value per foot of track to operate without problems ?

I am thinking about 90 FEET of track for my set ups (Both HO and O scale) with 25 cars attached. No inclines though

I have a feeling I will need auto trigger switches for this set up (if such a thing even exists)
I just don't know how much power say to 10ft of track is required and can't find it in any books or online

 

[julienjj]

huh the rail are in a closed loop so... if you are using dcc the booster adjust power automatically, using DC the throttle adjust power when you turn up the wheel

what i do understand from your question is that you whant that loco never loose power. this can be archived by running a wire on the side or under your track and feed power every 3-4 feet of track if you use 3' flexible track, if you do use small track (ez-track or simillar) that are 6 inch long, increase the number or feeder.

Try "Wiring layout track" on google

 

[RexHea]

With 90 feet of track, you are not going to have any problems with power no matter DC or DCC or if you have one or several locos, HO or O. Just make sure that the total current of the max number of locos used is no more than 80% of the rated power pack.
As said above, it is recommended to have feeds to the track from a bus for DCC and I would do the same for DC. However, my track feeds are about 6-9 feet depending on if it is a main or yard. I have DCC and about 1300 feet of track powered by a Digitrax Chief 8 amp and run Op sessions with an average 10-12 trains running at the same time. I have no booster, but I do split the power into power districts with a PM42. I still have plenty of power to spare. I have never seen more than 6.5 amps used. (Note: all these are "can motor" type locos)

 

[CSX Robert]

What is the power value per foot of track to operate without problems ?...

If I understand your question, you're wanting to know how much current(amps) you need per foot of track. Well, there is no answer to that question. The size of the layout has no direct bearing on it's current needs. The total current draw of all running locomotives and accessories is what determines the current needs of the layout, and it does not matter if you have 10, 100, 1,000, or 10,000 feet of track.