CHAPTER 24 Electronic Systems

• Define the terms : transducer, transistor, amplifier, integrated circuit, analog and digital.
• List common input and output transducers used in electronic circuits.
• Distinguish between analog and digital signal types used in electronic circuits.
• Explain the operation and semiconductor action of an NPN bipolar transistor.
• Define the transistor current gain factor (*).
• List the various modes of operation of transistors in electronic circuits.
• Relate devices such as FETs and Thyristors (SCRs) to transistor behaviour.
• Recall the method of biasing a transistor so that it will behave as a DC current amplifier or as an electronic switch.
• Recall the common types of integrated circuits (ICs) and their characteristics.
• Calculate the voltage gain (AV) of an operational amplifier with negative feedback.

Scientific Processes

• Sketch correctly a block diagram or schematic for a given circuit.
• Design simple transistor or IC circuits to perform a given task or gather electronic data.
• Communicate electronic information to others via an appropriate circuit diagram.
• Plot data necessary to graphically illustrate current gain for a simple transistor.
• Interpret signal input-output diagrams to determine a circuit's behaviour.
• Sketch variations in circuit designs to produce different outputs, such as frequency for an IC timer or clock circuit.
• Locate and comprehend transistor and IC circuit information from other text resources.
• Interpret circuit diagrams showing simple IC timers and amplifiers.

Complex Reasoning Processes

• Solve challenging problems involving DC current gain and switching action using transistor theory and circuits.
• Select relevant knowledge and data to satisfactorily explain the operation of complex circuits.
• Research fabrication techniques and the historical development of modern ICs.
• Model complex electronic circuits with the use of block diagrams as an analysis tool.
• Critically evaluate possible application circuits for devices, including fault finding or recognition of errors.

CHAPTER 24 SUMMARY

• Input transducers are used in electronic circuits to convert non-electrical energy forms into electrical energy represented as a current or voltage.
• Output transducers convert electrical currents and voltages into non-electrical energy forms.
• Electronic systems are often divided into various functional circuit blocks which may be represented as a block diagram.
• Electronic signals in a system may be either analog (continuously changing in waveform) or digital (two state, high or low, 0 or 1).
• In an NPN bipolar transistor a small base current causes a much larger collector current which is described as current amplification or gain .
• Transistors may be used as direct current (DC) amplifiers, or as fast acting switches.
• Field effect transistors (FETs) and Thyristors (SCRs) are close relatives of the simple bipolar transistor but provide different operating characteristics.
• Integrated circuits generally fall into two categories, Linear ICs, which process analog signals and Digital ICs, which process binary signals. They are commonly manufactured as dual in line (DIL) packages.
• Linear integrated circuits generally include operational amplifiers and timers.
• An operational amplifier (Op-Amp) is a linear IC with a very high open loop gain and a very high input impedance. They often are operated in circuit with closed loop feedback and contain both an inverting input (-) and a non-inverting input (+).
• Operational amplifiers increase the voltage difference between their two input terminals, with the voltage gain given by
• Free running or astable multivibrators form the basis of electronic timers or clocks.

Return to Objectives-Summary Menu Page page.