Illustration of an analogue signal profile using the relative duration of a rectangular pulse within a specified cycle (period), which must become shorter as the process becomes more dynamic (Figure P 34).
Pulse duration modulation is used in hydraulic systems, e.g. for the digital activation of the proportional solenoid of an (analogue) continuously adjustable valve. This exploits the fact that the solenoid produces an average current per impulse, depending on the pulse width. This process has the advantage of reducing losses during activation.
Figure P 34: Pulse duration modulation