Duty cycle

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In telecommunication and electronics, the term duty cycle has the following meanings:

The duty cycle D is defined as the ratio between the pulse duration (τ) and the period (T) of a rectangular waveform

• In a periodic phenomenon, the ratio of the duration of the phenomenon in a given period to the period.

duty cycle

where

D is the so-called duty cycle;

τ is the duration that the function is non-zero;

Τ is the period of the function.

For example, in an ideal pulse train (one having rectangular pulses), the duty cycle is the pulse duration divided by the pulse period. For a pulse train in which the pulse duration is 1 μs and the pulse period is 4 μs, the duty cycle is 0.25. The duty cycle of a square wave is 0.5, or 50%.

For another example, for a piece of electrical equipment, like an electric motor, the period for which it may be operated without deleterious effects, such as from overheating.

• The ratio of (a) the sum of all pulse durations during a specified period of continuous operation to (b) the total specified period of operation.

• In a continuously variable slope delta (CVSD) modulation converter, the mean proportion of binary "1" digits at the converter output in which each "1" indicates a run of a specified number of consecutive bits of the same polarity in the digital output signal.

Pulse-width modulation (PWM) is used in some music synthesizers to vary the duty-cycle of an oscillator during the performance, which has a subtle effect on the tone colors obtained.