1 Chapter 1 Electric Circuit Variables

2 Leyden jar for retaining electrical charges Electrical stimulation to a body History of Electrical Science Amber의 정전기 Electrical Generator Battery Positive & Negative Charge Electron vs. Ion Defibrillator

3 Figure A simple circuit. Charge : quantity of electricity responsible for electric phenomena Current : time rate of flow of electric charge past a given point Direct current : current of constant magnitude Time-varying current : current of varying magnitude Electric Circuits and Current Flow

4 Figure Current in a circuit element. Figure A direct current of magnitude I. Figure (a) A ramp with a slope M. (b) a sinusoid. (c) An exponential. I is a constant. The current I is zero for t<0. Electric Circuits and Current Flow

5 Example Example Electric Circuits and Current Flow

6 Figure Voltage across a circuit element Figure (a) The passive convention use for element voltage and current. (b) The passive convention is not used. Voltage, Power and Energy Voltage : energy required to move a positive charge from – to + Energy : capacity to perform work Power : time rate of expending or absorbing energy

7 Table Power Absorbed or Supplied by an Element Power and Energy

8 Example Example Power and Energy

9 Figure The problem-solving method. Circuit Analysis and Design

10 Figure An element with a voltmeter and ammeter. Figure The circuit from Figure with the ammeter probes reversed. Circuit Analysis and Design Example 1.7-1

11 Figure An element with a voltmeter and ammeter. Jet Valve Controller