Electronics Principles Teachers Pack V10

Clive W. Humphris

Description

Now published as a portable, learning, reference and subject revision guide, students, teachers and hobbyists can have their own low-cost portable version as an eBook.

For easy reading, a comprehensive list of hundreds of topics each with a graphic image and explanatory text act as a useful exam revision reminder or reference tool for professionals.

The accompanying software which brings all these images to life can be downloaded at no extra charge thereby providing an additional computer based interactive learning resource as an easy and enjoyable way to study.

A combined eBook and educational site licence software package at a tiny fraction of the previously published price.

Unlock accompanying software with your eBook receipt!

Sujets

• Electronique & télécommunications
• Sciences et techniques
• Technology
• Electronics
• Engineering
• Ingénierie
• Sciences appliquées
• Sciences appliquées
• Ingénierie
• Sciences appliquées

Informations

• Publié par: eBookIt.com
• Date de parution: 30 mars 2017
• Nombre de lectures: 0
• EAN13: 9781456617394
• Langue: English

Extrait

Table of Contents

Introduction.
Basic Electronics
Conductor And Insulator
Resistor Value Test.
Simple Dc Circuits
Types Of Switching.
Variable Voltages.
Ohm's Law.
DC Voltage
DC Current
Series and Parallel Resistors.
AC Measurement.
AC Voltage and Current.
AC Theory.
RCL Series.
RCL Parallel.
Capacitance.
Capacitors.
Inductance.
Inductors.
Impedance.
Radio and Communication.
Tuned Circuits.
Attenuators.
Passive Filters.
Active Filters.
Oscillators.
Circuit Theorems.
Complex Numbers.
DC Power.
AC Power.
Silicon Controlled Rectifier.
Power Supply.
Voltage Regulation.
Magnetism.
Electrical Machines.
Transformers.
Three Phase Systems.
Energy Transfer and Cost.
Atomic Structures.
Diode Theory.
Diode Applications.
Transistor Theory.
Bipolar Transistors.
Transistor Configurations.
Active Transistor Circuits.
Field Effect Transistors.
Basic Operational Amplifier.
Op-Amp Theory.
Op-Amp Applications.
Sum and Difference Amplifiers.
Analogue Multi-Meter.
Component Testing.
Additional Notes.
Electronics Principles Teachers Pack V10
by Clive W. Humphris Portable Learning, Reference and Revision Tools. Copyright by eptsoft limited 2012 All rights reserved. Acknowledgement. Our thanks and appreciation goes to John D. Ransley MIEE from Whitbourne in Worcestershire for all his help and expert guidance in developing this software title. Introduction.
Electronics Principles Teachers Pack V10 eBook covers all the topics of this popular software title used in schools and colleges worldwide for over twenty years.
Now published as a portable, learning, reference and subject revision guide students and teachers can have their own low-cost version as an eBook.
The PC educational software to accompany your eBook provides you with an easy and enjoyable way to study your chosen subject.
See Additional Notes for instructions to download the highly interactive PC software for your school. Used in thousands of schools and colleges worldwide the software is designed to work as a traditional textbook on your PC screen. Comprising hundreds of menu selected colourful topics where the graphic images (from your eBook) are brought to life for every value change along with many additional learning software features.
With the fully integrated whiteboard technology whole class teaching, topics can be displayed full screen where values and selections can be interactively explored by pointing and clicking the input buttons.
Full colour printed is available for student handouts (using your values and selections) or images and text pasted to make student assignments.
Various additional software editors are included to enable your own calculations to be explored and evaluated from simple algebraic equations to complex formulae.
A unique eBook and educational site licence software package at a tiny fraction of the previously published price.
BASIC ELECTRONICS: Finding Circuit Voltages.

When calculating a voltage, in this case a DC we are determining the potential difference (PD) developed across an electrical device due to the current flowing through it. This will be explained further when we come to explore Ohm's Law. In this instance we are finding the voltages developed across the resistor and the lamp. The components shown are in what is called a series circuit, the resistor is in series with the lamp as the electron current flow is through one followed by the other. Remove either the resistor or the lamp and the circuit ceases to function, what's known as an open-circuit. This simple circuit provides the opportunity to introduce some electronics mathematics which for the moment its sufficient to say that if we want to find how much current is being drawn from the battery when the lamp is lit, we can calculate it. Found by dividing the sum of the voltages across the resistor and lamp by the total circuit resistance. When the individual potential differences are added they will always equal the supply potential of the battery. This is known as Kirchhoff's Voltage Law. Note: the polarity of the voltage. This is important when it comes to connecting your Voltage Test Meter where the black lead is applied to the more negative part of the circuit and the red lead to the more positive.
BASIC ELECTRONICS: Measuring Voltage and Current.

The electric current which flows through a circuit is a measure of the rate of flow of electric charge (electron movement) past any given point. An ammeter is used to measure current flow, but before we can do this, it is first necessary to insert the meter into the current path within the circuit. Note voltages appear across electrical devices (shown by the voltmeter connections) which posses resistance, whereas current flows through them. The current can also be calculated using the formula for Ohm's Law. The ammeter can be placed at any point in the circuit and will always give the same current reading, which is determined by the battery potential voltage divided by the resistor value added to the lamp resistance or the total circuit resistance. As the value of R1 is increased then the current is limited around the circuit and in a practical situation the lamp would glow less brightly. As the resistance of the lamp is fixed the voltage developed across the filament will also fall in direct proportion to the current I.
BASIC ELECTRONICS: Variable Resistance.

A variable resistor (known as a potentiometer) is a fixed value resistor onto which a slider is attached to tap off the resistance at any given point across a carbon track. VR1 is connected to form a potential divider circuit, the output voltage depending upon the slider position. Move the slider towards point [a] and the output voltage increases, towards [c] and it decreases. Is there a linear relationship between voltage output and slider position i.e. do you get half the voltage output at the control mid point? The answer should be yes, but only because the output is open circuit. As soon as a load resistance is connected across the output this smooth linear voltage variation from one end of the control to the other will be upset and will be explained when we come to voltage dividers. Variable resistors are commonly found in modern audio amplifiers where the variable DC voltage is used to adjust the level of volume, bass and treble within an integrated circuit amplifier using a DC controlled attenuator. Variable resistors can also be found in AC circuits where the signal attenuation can be adjusted from maximum to zero by varying the slider position. There are two types of potentiometer, linear, where the resistance across the track increases evenly from one end to the other and logarithmic where there is a greater change of resistance to angle of rotation at one end than the other. The latter are less common now, but can upset measurements if the wrong type is used. Where higher currents are involved potentiometers are available with a wire wound track and printed circuit boards demand sub-miniature horizontal and vertical mounting types. Finally for greater precision multiple turn resistors should be used.
BASIC ELECTRONICS: Adding Positive Values.

When the numbers to be added are all positive the total will be the cumulative addition of each new value. An example is when adding resistor values in series, as each resistor is connected the total resistance becomes larger. Voltages and currents, as we shall see later, can only be added directly when they have the same phase angle or direction.
BASIC ELECTRONICS: Adding Negative Values.

A negative current is simply a way of mathematically defining a current flowing in the opposite direction to a positive one. When -I1, -I2 and -I3 are added together at point X to become -I total. Normally its good practice to include brackets ( ) around a negative number. It avoids confusion of + and - operators appearing next to one another. It's useful to remember that a minus added to a minus is just a bigger minus.
BASIC ELECTRONICS: Adding Signed Values.

Positive and negative voltages developed across a circuit will cancel each other when added together, the resultant or total taking the sign of the greater quantity. Voltages and currents normally represent peak or RMS values or any other instantaneous measurement, any can be used so long as the same method is applied throughout. Adding positive and negative numbers is common in AC circuits, the (+) and (-) signs indicating voltages or currents in phase opposition. During the first half of the waveform the resultant will be in one phase, then reversed during the following half cycle.
BASIC ELECTRONICS: Algebraic Addition of Currents.

Currents can be made to flow in both directions through a conductor, or as in this example a resistor. Some electrons moving from left to right will be cancelled out by those moving right to left, the sign just represents one or other direction. The resultant current being I1 - I2 or I2 - I1. This is the same as adding a positive current (flowing in one direction) to a negative current (in the opposite direction). You will note the sign is not included for the final result as the answer just represents an amount of current flowing in the circuit, the direction is usually unimportant for further calculations and could complicate the result of say, Ohm's Law by showing a negative voltage.
BASIC ELECTRONICS: Subtracting Signed Voltages.

As an example of subtracting a negative value from a positive. Consider a series resistor network, which measures 20V at one end and -11V at the other. What is the potential difference between the two ends? The rule for subtracting a negative value from a positive is, change the sign of the negative (-n2) and add. When calculating the voltage or potential difference, ignore the sign of the final answer.
BASIC ELECTRONICS: Subtracting Negative Currents.

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