I have a Digitrax sound decoder in one of my locos (a Kato P42) and there are DCC CVs for certain elements of the diesel locomotive’s operation which generates sound. Can anyone explain the following to me, so I have a better understanding?
Air Dryer Rate (what is the function of the air dryer?)
Popoff Rate (what is the popoff exactly?)
Air Compressor – this is for the braking system, or does it have other uses?
first item, google locomotive air dryer and you will get a good explanation, better than i could give you.
second-as air pressure builds up, a relief or popoff valve releases the excess to prevent over pressurizing the system. functions like the safety valve on a steam engine. (not to be confused with the TV preacher named Peter Popoff)
third-compressed air was used for many things besides brakes. horn, bell ringer, sanding, cab signal, ats forestall warning alarm, windshield wipers, control air for electro-pneumatic controls and probably a bunch more i can’t remember at this time.
Charlie
The popoff rate will tell the chipset how often to turn on the pop off vavle sound. It doesn’t need to be a lot unless you sit in the yard a lot.
The air dryer takes moisture out of the compressed air so that bad things don’t happen with various equipment requiring compressed air. If you’re in a humid climate it will work more than in a dry climate.
The air compressor works more as it’s used more to maintain system pressure. It fills the resevoir tanks. When you initially make up a train, if you don’t have yard air, they fill the train up before you move.
Richard
The guys already have things pretty well covered as to what.
Now as to what each of the first two sounds sound like from your decoder, they’re somewhere on the spectrum of sounds from pssst to pffft to buoosh.
The air compressor will make a thumping, hammering, clunking sort of sound that take a considerably longer time (a minute or longer) to occur than the first two.
Thanks guys, this all helps!