(10-29-2017, 11:48 PM)Pheidippides Wrote: Hopefully the GrandLinq partners' experiences in Australia and other places will help spare us that trauma.
It's been a while since I've watched a full POV, but I don't recall any signal arms anywhere on G:Link.
(10-30-2017, 03:59 PM)KevinT Wrote: The nominal voltage of the OCS is 750V, but the max is 900V and under the heavy load of two accelerating double trains it's permitted to drop as low as 525V. By using a relaxation oscillator (think of the whine of a charging camera flash) to build up X amount of charge and then dump it into the light for Y amount of time, X can vary with the voltage: You get a slower blink at the lower voltage and a faster blink at the higher voltage, but the duration and brightness of the blink is always the same.
I guess I had thought that the lamp that was blinking was probably a PLC-driven output, not something directly driven by the voltage on the line itself. I guess what you're suggesting makes more sense, though - one less thing to go wrong or to fail. Safety-related stuff like this probably has to be as simple as possible (ie, not subject to a bad rung of Ladder Logic resulting in someone getting fried because the light didn't come on!)
ijmorlan: As for the fence... while all you have typed up there may make sense, none of us (that I know of) have ever seen the "Rule book" from Transport Canada (or whoever) that decides why and where the fences are going up. There is probably some very strict and carefully guided calculation about how these locations are determined. It's impossible for us to speculate on why these things are going up where they are. You'll just exhaust yourself trying.