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Electrical & Mechanical Oscillations OS Jones
ELECTRICAL AND MECHANICAL OSCILLATIONS An Introduction BY
D. S. JONES
ROUTLEDGE AND KEGAN PAUL LONDON
First published 1961 by Routledge & Kegan Paul Ltd Broadway House, 68-74 Carter Lane London, E.C.4 Printed in Great Britain by Latimer, Trend & Co Ltd, Plymouth
© D. S. Jones 1961 No part of this book may be reproduced in any form without permission from the publisher, except for the quotation of brief passages in criticism Second impression 1965
Contents
page vii 1 1 1.2. The equilibrium of a conservative system with one degree offreedom 5 1.3. Stability 9 1.4. The principle of virtual work 13 Exercises 18
Preface 1. Equilibrium 1.1. Introduction
2. Harmonic Oscillations
20
2.1. The motion of a conservative system near equilibrium 20 2.2. Examples 23 2.3. Forced oscillations 30 Exercises
36
3. The Effect of Friction
3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7. 3.8.
39
Introduction Free oscillations with viscous damping Forced oscillations with viscous damping The production of heat Frequency measurement Forces due to mountings Amplitude measurement Operational solution
39 41 44 48 49
Exercises
55 v
50
51
53
CONTENTS
page 57
4. Electrical Circuits
4.1. 4.2. 4.3. 4.4. 4.5.
The fundamental c£rcuit elements Kt"rchhoff's laws The electro-mechanical analogy Complex impedances Operat£onal impedances
57 59 64 65
Exercises
71
5. Non-Linear Oscillations 5.1. Introduction 5.2. The phase plane 5.3. Equilibrium 5.4. Slightly non-linear damping 5.5. Relaxation oscillations 5.6. Forced oscillations Exercises
69
74 74 76 77 83
90 95 99
Answers to Exercises
10