## Chapter Objectives and Summaries

### CHAPTER 23 Electronics

LEARNING OBJECTIVES
Knowledge of subject matter
• Use correct symbols to represent electronic devices and circuits.
• Identify any electronic component either by direct observation or recognition of an appropriate circuit symbol.
• Recall the method of operation of selected electronic testing instruments.
• Define the quantities of measurement used in resistance, capacitance and inductance.
• Inter convert units for AC voltage measurement ( VRMS : VP : VPP )
• Recall appropriate practical applications of resistors, capacitors, and inductors or their combinations.
• Define and deduce the time constants as applied to RC and or RL circuits.
• Describe the nature of P and N type semiconductors in terms of their crystalline structures and charge carriers during electrical conductivity.
• List common semiconductor devices used in electronics.
• Explain the operation of a PN diode and its use in AC rectification.
• State the bias conditions necessary for conduction within a semiconductor device such as a PN diode.

Scientific Processes

• Discuss the role that the historical development in electronics has played in modern societal changes and our way of life.
• Classify electronic components on the basis of physical structure, colour coding, labelling or method of operation.
• Interpret I/V curves and data tables to determine the nature of resistance or reactance at a given frequency.
• Communicate electronic information via an appropriate electronic circuit diagram.
• Design simple circuits to perform a given task or gather numerical data.

Complex reasoning processes

• Solve challenging problems using interconnected relationships between resistance, capacitance, inductance, DC voltage and current including complex circuit analysis.
• Derive new relationships algebraically or graphically from given data.
• Compare the DC behaviour of R, L and C components in circuits.
• Select the relevant properties of an electronic component in order to predict its behaviour in any given circuit.
• Model complex electrical circuits with the use of block diagrams as an analysis tool.

CHAPTER 23 SUMMARY

• Multimeters, cathode ray oscilloscopes and DC/AC power supplies are commonly used electronic test instruments.
• AC voltage waveforms are commonly measured in root mean square (VRMS), peak to peak (VPP) or peak (VP) modes.
• Electronic resistors are usually identified by a colour code within a preferred value system and may be used as current control or voltage divider elements in electronic circuits.
• Electronic components, such as resistors, capacitors and inductors, are manufactured in a wide range of types, tolerances and physical variation for numerous circuit design applications.
• Measurement units for resistance (R) are ohms , capacitance (C) are farads (F) and inductance (L) are henry (H).
• A capacitor is an electrical charge storage device and may be used in DC timing circuits or as AC high frequency bypass devices and direct current blocking devices. It stores energy in a electric field.
• The time constant of an RC series timing circuit is given by t=R/C in seconds.
• An inductor is an electromagnetic coil device that stores energy in a magnetic field. It can act as a filter or block to high frequency alternating currents.
• Semiconductors are the crystalline silicon based materials that make up modern electronic devices such as PN diodes.
• Depending on the bias or voltage polarity applied to a PN junction diode, it will either behave as an insulator or a very good conductor.
• Semiconductor action is based on both negative electrons and positive holes and a process of chemical impurity doping.
• PN junction diodes are used in the process of AC rectification and are the basis of power supply design, both half-wave and full-wave action.
• The output of a rectifier circuit may be filtered or smoothed by a large value capacitor placed in parallel across the output and regulated by a zener diode.
• Solar cells, LED's, LDR's, thermistors and zener diodes are some of the practical applications of semiconductor technology in electronics.