When alternating waveforms have the same frequency but different phase, they are said to be “Out of phase”. In the above picture,we can see three waves which are starting at the origin of the axis, leading at origin and lagging at the origin of the coordinate axis respectively.īack to top Phase Difference of Waveforms Out of Phase If the voltage and angular velocities of the two waveforms are same, then their phase is also same at any instant of time. Phase Relationship of a Sinusoidal WaveformĮvery alternating waveform will have its current, voltage and frequency. If Φ 0, then the phase angle of the wave is said to be in a positive phase. Ωt is the angular velocity (radians / Sec) The phase difference of sine waveforms can be expressed by below given equation, using maximum voltage or amplitude of the wave forms,Īmax is the amplitude of the measures sine wave The phase shift of the waveforms can be represented in time period (T) also. Where f is the frequency of the waveform and t is the time period.įor example, if two sine waves have the same frequency and have a phase shift of π/2 radians, then the phases of the waves can be defined as (nπ + 1) and nπ radians. The time interval and phase of a waveform are inversely proportional to each other. To understand this concept clearly, observe the figure below. Phase opposition: When the phase difference between two waves is 180 0 (it may be = + 180 0 or – 180 0), then the waves are said to be in ‘Phase opposition. Phase quadrature: When the phase difference between two waves is 90 0 (it may be = + 90 0 or – 90 0), then the waves are said to be in ‘Phase quadrature’. Leading phase means, a waveform is ahead of another wave with the same frequency and Lagging phase means, a waveform is behind another wave with the same frequency. The complete phase of a waveform can be defined as 2π radians or 360 degrees. The phase difference represented by the Greek letter Phi (Φ). This is also called as “Phase angle” or “Phase offset”. The phase difference of a sine wave can be defined as “The time interval by which a wave leads by or lags by another wave” and the phase difference is not a property of only one wave, it’s the relative property to two or more waves. Voltage and Current Phase Relationships to R,L,C.Phase Relationship of a Sinusoidal Waveform.