A 'throttle' is a circular plate situated usually downstream of a carburretor in the airstream of the inlet manifold. It is attached to a bar across its center which is hinged so that when turned it can present it's edge to the airflow with minimum impedance, or turn through 90 degrees and completely block the airflow. By this means the mass airflow allowed to pass into the engine, and therefore it's power output can be varied.
Since throttles are only used with carburretors, they are only strictly relevant when talking about engines which use carburretors. (e.g. piston engines).
Gas turbine engines do not have carburretors, but adjust the amount of fuel pumped into the combustion chambers to vary the thrust that the engine will produce, (or power, if it is a turbo prop.).
Therefore, a more correct term for the "engine output control levers" - when applied to gas turbines - is 'thrust levers', since that is the parameter which is varied by adjustment of their position.
Having said all that, they are often called throttles/throttle levers, because everyone knows what that means - a hangover from the piston engined aircraft a lot of us started on - it's a bit like calling your vacuum cleaner a 'Hoover' I suppose.
It's a bit of a pedantic point, but I hope this helps.
U
Last edited by Uplinker; 20th June 2012 at 02:08.