Idle speed

Idle means the operation of a system or a machine without this does the work for which it is intended. Systems often require a certain starting time, to the desired values ​​, all parameters ( eg, temperature, also known as operating ) reach.

Basics

Since approaching often takes a lot of energy, it is to be, under certain circumstances, economic, systems run without load, as they disable it completely and boot up again later. However, the avoidance of unnecessary idling is a potential for energy saving.

Combustion engines

Combustion engines are below a minimum speed of the crankshaft to a halt. This speed is in most engines of motor vehicles between 700 and 900 min-1 min -1. So that the motor stops the rotational speed, it is idle, a small amount of fuel - air mixture ( the conventional gasoline engine ) or a fuel ( diesel engine, a direct injection gasoline engine ), the so-called state of gas is supplied. In fuel injection systems comes to a separate speed controller for use. Carburetors are equipped with a separate pilot jet. In most cases the idle speed is a little higher than is absolutely necessary adjusted, thus lower vibrations and a sudden change in the load operation does not go out of the engine.

Electrical Engineering

As an idling state is known in the electrical engineering, in which to an electric voltage source (or a power generator ), no electric load is connected or is operated in the on mode.

Shutdown

In optimized for best fuel economy automobiles, the engine is not idling, but automatically turned off when its power is not required by means of a so-called start-stop system. When the accelerator pedal is then depressed, the engine is automatically restarted. However, to save main disadvantage of this way fuel is a greater wear and tear, which is noticeable in the engine particularly at the crankshaft. This is due to their almost wear-free storage, however, the motion of the waves requires, which takes place at every new start of increased abrasion.