<P> where D (\ displaystyle D) is the duty cycle, P W (\ displaystyle PW) is the pulse width (pulse active time), and T (\ displaystyle T) is the total period of the signal . Thus, a 60% duty cycle means the signal is on 60% of the time but off 40% of the time . The "on time" for a 60% duty cycle could be a fraction of a second, a day, or even a week, depending on the length of the period . </P> <P> Duty cycles can be used to describe the percent time of an active signal in an electrical device such as the power switch in a switching power supply or the firing of action potentials by a living system such as a neuron . </P> <P> The duty factor for periodic signal expresses the same notion, but is usually scaled to a maximum of one rather than 100% . </P> <P> In electronics, duty cycle is the percentage of the ratio of pulse duration, or pulse width (PW) to the total period (T) of the waveform . It is generally used to represent time duration of a pulse when it is high (1). In digital electronics, signals are used in rectangular waveform which are represented by logic 1 and logic 0 . Logic 1 stands for presence of an electric pulse and 0 for absence of an electric pulse . For example, a signal (10101010) has 50% duty cycle, because the pulse remains high for 1 / 2 of the period or low for 1 / 2 of the period . Similarly, for pulse (10001000) the duty cycle will be 25% because the pulse remains high only for 1 / 4 of the period and remains low for 3 / 4 of the period . Electrical motors typically use less than a 100% duty cycle . For example, if a motor runs for one out of 100 seconds, or 1 / 100 of the time, then, its duty cycle is 1 / 100, or 1 percent . </P>

Continuous wave systems have a duty factor of