Standard

ELC 109 - Alternating Current I

Course Description:

Introduces the theory and application of varying sine wave voltages and current. Topics include: AC wave generation factors such as peak, peak to peak, average, and RMS values of AC voltage and current; frequency and phase relationship in resistive, RL, RC, and RLC circuits; and impedance, admittance, and conductance power factors calculated from given and/or measured data.

Competency Areas:	Hours
AC Wave Generation	Class	4
Frequency and Phase Relationship	D. Lab	6
Impedance, Admittance, and Conductance Power Factors	P. Lab/O.B.I.	0
	Credit	7
Prerequisite: ELC 108, MAT 105
Corequisite:
Course Guide

Competency	After completing this section, the student will:	Hours
		Class	D. Lab	P. Lab/ O.B.I.
AC WAVE GENERATION		4	10	0
Magnetism	Explain the principles of magnetism.
	Demonstrate application of magnetic principles.
Sine wave	Describe sign waves generated by alternating current.
Alternating current	Define alternating current.
Voltage and current values	Measure AC voltage and current values.
Alternating voltage generator	Describe the preparation of a basic AC generator.
FREQUENCY AND PHASE RELATIONSHIP		6	10	0
Frequency period	Determine the frequency period of an AC sine wave.
Wavelength	Determine the wavelength of an AC sine wave.
Phase angle, time factor	Determine the phase angle of an AC sine wave.
Nonsinusoidal AC waveforms	Name three types of AC waves other than a sine wave.
Harmonic frequencies	Describe harmonic frequencies.
IMPEDANCE, ADMITTANCE, AND CONDUCTANCE POWER FACTORS		30	40	0
Inductance, reactance, self inductance, and mutual inductance	Define inductance.
	Define induction by alternating current.
	Define self inductance.
	Define self inducted voltage (VI).
(VI) opposition to a change in current Mutual inductance	Draw a vector diagram showing phase relationships.
Inductance in series or parallel	Define the unit of energy and calculate the strength of an induced voltage.
Energy in magnetic field of inductance
Inductive reactance
(XL) reduction in the amount of I	Determine the reactance of a coil if given the inductance and the frequency.
XL = 2(3.14) FL
Series and parallel inductive reactance
Ohm’s law applied to XL
Applications of XL for different frequencies
R-L circuits
Sine wave IL lags VL 90 degrees	Calculate the phase angle for series and parallel circuits.
XL and R in series
Impedance (Z)	Determine the impedance of an RL circuit.
XL and R in parallel
Q of a coil
AF and RF chokes
Capacitance
Storing a charge	Identify capacitors and capacitor symbols.
Charging and discharging	Explain how a capacitor operates.
Time constants
Farad unit of capacitance	Name the unit of measurement for capacitors.
Typical capacitors
Parallel capacitances	Demonstrate the effect of capacitors in series and parallel.
Series capacitances
Capacitive reactance
Alternating current in a capacitive circuit
X = 1/[2(3.14)FC]	Define capacitive reactance and compute its value in Ohm’s law when the capacitance and operating frequency are known.
Series and parallel capacitive reactance
Ohm’s law applied to XC
Applications of capacitive reactance
Sine wave charge and discharge current
R-C circuits
Sine-wave Vc lags Ic by 90 degrees	Show by vector diagram the phase relationship between E and I in an RC circuit.
X and R in series
X and R in parallel
RF and AF coupling capacitors
Capacitive voltage dividers	Calculate voltage drops across each capacitor in a capacitive voltage divider.
General case of capacitive current Ic
Calculating the RC time constant	Calculate the charge and discharge time. of an RC circuit.
A-C circuits
AC circuits with resistance only	Determine E,I,R,XL,X,Z,Q, PF, true and apparent power for AC R-UC circuits using measurements and calculations.
Circuits with XL only
Circuits with X only
Opposite reactance cancel	Define and calculate admittance, susceptance, and conductance.
Series reactance and resistance
Parallel reactance and resistance	Analyze both series and parallel AC circuits and determine their current and voltage values

Suggested Resources

Books:

Fry, J. (1986). AC electronics. Benton Harbor, MI: Heathkit Educational Systems.

Grob, B. (1987). Basic electronics (5th ed.). New York: McGraw-Hill.

Malvino, A. P. (1984). Electronic principles (3rd ed.). New York: McGraw-Hill.

Manville, R. R. (1982). How AC and DC circuits work (2nd ed.). Indianapolis, IN: Howard W. Sams.

Patrick, D. R., & Fardo, S. W. (1984). Electricity and electronics. Englewood Cliffs, NJ: Prentice Hall.

Patrick, D. R., & Fardo, S. W. (1989). Understanding AC circuits: Concepts, experiments, and troubleshooting. Englewood Cliffs, NJ: Prentice Hall.

Sharader, R. L (1980). Electronic communications (5th ed.). New York: McGraw-Hill.