Neil Storey1

Apuntes

Neil Storey, Electronics : A Systems Approach, 5 th Edition © Pearson Education Limited 2013 1.1 Quantities and Units Lesson pp_01 M. Gioannini Neil Storey, Electronics : A Systems Approach, 5 th Edition © Pearson Education Limited 2013 1.2 Electrical Circuits Electric charge – an amount of electrical energy– can be positive or negative  Electric current – a flow of electrical charge, often a flow of electrons– conventional current is in the opposite direction to a flow of electrons  Current flow in a circuit – a sustained current needs a complete circuit– also requires a stimulus to cause the charge to flow Neil Storey, Electronics : A Systems Approach, 5 th Edition © Pearson Education Limited 2013 1.3 Current and Charge An electric current is a flow of electric charge  At an atomic level a current is a flow of electrons – each electron has a charge of 1.6  10 -19 coulombs – conventional current flows in the opposite direction  Rearranging above expression gives  For constant current t Q I d d    dt I Q t I Q   Neil Storey, Electronics : A Systems Approach, 5 th Edition © Pearson Education Limited 2013 1.4 Electromot...