I know we have members here that are into trains so I figure the answer is among you.

When I see the diesel electric commuter trains Photo coming into the station they sound like the diesel is idling. When they leave they sound like they rev up.

When I think of a generator I imagine a constant speed to maintain a voltage.

So what is going on?

If the generator is ramped up and down how is the voltage maintained for the aux systems like electronics, lighting, HVAC etc.

Do they have more than one source of power?

Pleases fill me in. [Linked Image]

Bob Badger
Construction & Maintenance Electrician
Massachusetts