AC circuits – phase difference and power factor (cos φ)

Design & TechnologyElectrical Engineering & SafetyAges 17–18

An AC source u = U√2·sin(ωt) supplies a purely resistive load, an R–L load (motor, ballast), an R–C load, or a series R–L–C load. Real-time graphs of u(t) and i(t) show the current lagging the voltage in an inductive load and leading it in a capacitive load, while the phasor diagram alongside plots U_R, U_L, U_C and the phase angle φ. Drag the R, L, C sliders to see the impedance Z, power factor cos φ and real power P = UIcos φ change, including at resonance.