Questions about PWM:

I am trying to do a project that is a digital throttle, driving the track with a plus width modulated (PWM) constant frequency. I have a commercial analog throttle that generates this PWM voltage source (it is at about 18KHZ) but I want to do it digitally for reason too complicated to explain here.

I wanted a project of limited scope that would still provide evidence of progress.  Modeling some water sounded like a plan, so I got to work on the Cedar Creek scene from last year's MRH Forum Challenge.  For construction of these scene in preparation for water, see http://model-railroad-hobbyist.com/node/8540 .

So I've decided to do a shelf layout of the Pacific Fruit Express style. I got an icing shed and will be picking up a produce storage distributor. I have a couple of questions regarding the colors of the Pacific Fruit Express cars. I'm intending to use the orange ones, but I've noticed that they have either brown (or black) or red ends on the cars. What's the difference? Years they changed the colors? I'm going for the late 70's on the layout possibly a steam loco as well into the 60's.

This depot was put in service at Amwaco, Idaho in 1910 and was used till about 1922.  On the Lake Creek and Coeur d'Alene Railroad line, which ran from Manito, WA about 14 to 18 miles to Lake Coeur d'Alene.  They carried passengers to Amwaco to a steam ship Harrison,that transported them to Harrison, Idaho then they boarded a train to travel on up to the Silver Valley and Wallace, Idaho