Inductive Reactance Electronics
Inductors in AC Circuits
Inductance Inductance opposes a change in current. Inductors create a voltage that opposes the current. Counter EMF (voltage) L v
Inductance The Henry (symbol: H) is the SI unit of inductance. It is named after the American physicist Joseph Henry..
Current Voltage Capacitor in DC
ELI
Voltage InductanceCurrent Voltage leads Current in an Inductive Circuit
Current Voltage Inductance in AC
Current Voltage I = I p sin(2πft) I p -Peak Current 2π-Cycle f-frequency(Hz) t-time(seconds) V = L di/dt V = L I p (2πf)cos(2πft) V p = I p (2πf)L V = L d(I p sin(2πft))/dt
V p = I p 2πfL R = 2πfL Inductive Reactance X L = 2πfL L is an Active Component V p /I p = 2πfL
Calculate the maximum current in a coil which has an inductance of 3 mH. The frequency is 60Hz. The maximum voltage across the coil is 6 V. X L = 2πfL L=3mH E=6V f=60Hz X L = 2π(60Hz)(.003H) X L = 1.13Ω I = E/X L I = 6V/1.13Ω I = 5.3A
Inductive/Resistive Circuit 90° Phase Shift caused by Inductor Impedance, Z, is calculated by adding X L and R vectorially. XLXL R Z
What is the impedance of a 100mH choke in series with a 470 Ω resistor with a 12V, 60Hz applied across them? What is the phase angle between voltage and current? X L = 2πfL L=100mH E=12V f=60Hz X L = 2π(60Hz)(.1H) X L = 37.7Ω R=470Ω
XLXL R Z
Current Voltage Inductance in AC 4.6°
Inductance in AC Circuits
1mF = 1 X F 1μF = 1 X F 1nF = 1 X F 1pF = 1 X F Capacitor Values
RLC Circuits
90° Phase Shift caused by Inductor XLXL R Z XCXC -90° Phase Shift caused by Capacitor
X c = 1/(2πfC) X c = 1/(2π(60)(1.5X10 -6 ) X c = 1768Ω X L = 2πfL X L = 2π(60)(0.65) X L = 245Ω XLXL R Z XCXC = -81° ICE – Current leads Voltage by 81°
Resonance The frequency where X L = X C The Circuit becomes a purely resistive circuit X c = 1/(2πfC) X L = 2πfL 1/(2πfC) = 2πfL X c = X L 1/(4π 2 CL) = f 2 = f
161 Hz= f
Worksheet Lab 2-6 Capacitors In AC Circuits Problems
Reactance Test Classwork Lab 7, Book 2 – Capacitive Reactance Worksheets Lab 2-5 Lab 2-6 Lab 2-8 Lab 2-9 Lab 2-11 Lab 2-12 Lab 2-13 } Due the day of the test!!