Alternating Current Module 26201-11

Upon completion of this module, you will be able to do the following: Objectives  Upon completion of this module, you will be able to do the following: 1. Calculate the peak and effective voltage or current values for an AC waveform. 2. Calculate the phase relationship between two AC waveforms. 3. Describe the voltage and current phase relationship in a resistive AC circuit. 4. Describe the voltage and current transients that occur in an inductive circuit. 5. Define inductive reactance and state how it is affected by frequency. 6. Describe the voltage and current transients that occur in a capacitive circuit. 7. Define capacitive reactance and state how it is affected by frequency. 8. Explain the relationship between voltage and current in the following types of AC circuits: • RL circuit • RC circuit • LC circuit • RLC circuit 9. Explain the following terms as they relate to AC circuits: • True power • Apparent power • Reactive power • Power factor 10. Explain basic transformer action.

Figure 1 – Conductor moving across a magnetic field

Figure 2 – Angle versus rate of cutting lines of flux

Figure 3 – One cycle of alternating voltage

Figure 4 – Frequency measurement

Figure 5 – Amplitude values for a sine wave

Figure 6 – Voltage waveforms 90° out of phase

Figure 7 – Waves in phase

Figure 8 – AC waveforms

Figure 9 – Resistive AC circuit

Figure 10 – Voltage and current in a resistive AC circuit

Figure 11 – Factors affecting the inductance of a coil

Figure 12 – Inductor voltage and current relationship

Figure 13 – Capacitors

Figure 14 – Charging and discharging a capacitor

Figure 15 – Capacitors in parallel

Figure 16 – Capacitors in series

Figure 17 – Voltage and current in a capacitive AC circuit

Figure 18 – Summary of AC circuit phase relationships

Figure 19 – Series RL circuit and vector diagram

Figure 20 – Series RL circuit with waveforms and vector diagram

Table 1 – Series R and XL Combinations

Figure 21 – Parallel RL circuit with waveforms and vector diagram

Table 2 – Parallel R and XL Combinations

Figure 22 – Series RC circuit with vector diagrams

Table 3 – Series R and XC Combinations

Figure 23 – Parallel RC circuit with vector diagrams

Table 4 – Parallel R and XC Combinations

Figure 24 – Series LC circuit with vector diagram

Figure 25 – Parallel LC circuit with vector diagram

Figure 26 – Series RLC circuit and vector diagram

Figure 27 – Parallel RLC circuit and vector diagram

Figure 28 – Power calculations in an AC circuit

Figure 29 – RLC circuit calculation

Figure 30 – Power triangle

Figure 31 – Basic components of a transformer

Figure 32 – Transformer action

Figure 33 – Steel laminated core

Figure 34 – Cutaway view of a transformer core

Figure 35 – Transformer winding polarity

Figure 36 – Transformer turns ratio

Figure 37 – Tapped transformers

Figure 38 – Importance of an isolation transformer

Figure 39 – Autotransformer schematic diagram

Figure 40 – Current transformer schematic diagram

Figure 41 – Potential transformer.

Supplemental Art

Course Map

Left-Hand Rule for Generators

RMS Amplitude

What’s Wrong With This Picture?

AC Circuits

Turns and Voltage Ratios