Admittance, Y = 1/Z

1. Complex Impedance Admittance, Y = 1/Z • Tips • ELI the ICE man lives in SARLPARC • Inductive Circuits: Voltage leads current (phase angle is positive) • Capacitive Circuits: Voltage lags current (phase angle is negative) • SARL: Series Above Resonance appears Inductive • PARC: Parallel Above Resonance appears Capacitive • If reactance & resistance have same magnitude, phase angle = ±45° • If reactance is less than resistance, phase angle is less than ±45° • If reactance is greater than resistance, phase angle is greater than ±45° • If the reactance = 0, phase angle = 0. Circuit is purely resistive., voltage & current in phase. • For series circuits, add impedances • For parallel circuits, add admittances • When taking the reciprocal of an angle, flip the sign • In parallel circuits, the resultant impedance is smaller than the resistance or reactance. Plotting Impedance • Resistance (R) along positive x-axis (right). • Inductive reactance (XL) along positive y-axis (up). • Capacitive reactance (XC) along negative y-axis (down). • Negative x-axis (left) not used. • Resonant Freq , Quality Factor, Band Width • Resonant Frequency (fR) = 1 / (2π√LC ) • Quality factor (Q) = PS / PD= X / R • Half-power bandwidth (BW) = f2-f1 = Δf = f0 / Q = fR / Q Powdered Iron Cores • N = 100 x √L / AL • L = Inductance in μH • AL = Inductance Index in μH/(100 turns). • N = Number of Turns • Power Equations • Apparent Power (v-a) P = I x E • Real Power (watts)  P = I x E x cos(θ) • Power Factor (PF) = cos(θ) Ferrite Cores • N = 1000 x √L / AL • L = Inductance in mH • AL = Inductance Index in mH/(1000 turns) • N = Number of Turns