Capacitors and Inductors

Capacitors and Inductors

Introduction

• Two more linear, ideal basic passive circuit elements.
• Energy storage elements stored in both magnetic and electric fields.
• They found continual applications in more practical circuits such as filters, integrators, differentiators, circuit breakers and automobile ignition circuit.
• Circuit analysis techniques and theorems applied to purely resistive circuits are equally applicable to circuits with inductors and capacitors.

Capacitors

• Electrical component that consists of two conductors separated by an insulator or dielectric material.
• Its behavior based on phenomenon associated with electric fields, which the source is voltage.
• A time-varying electric fields produce a current flow in the space occupied by the fields.
• Capacitance is the circuit parameter which relates the displacement current to the voltage.

Parallel capacitances

• The equivalent capacitance of N parallel-connected capacitors is the sum of the individual capacitances.

Series capacitances

• The equivalent capacitance of series-connected capacitors is the reciprocal of the sum of the reciprocals of the individual capacitances.

 

Inductors

• Electrical component that opposes any change in electrical current.
• Composed of a coil or wire wound around a non-magnetic core/magnetic core.
• Its behavior based on phenomenon associated with magnetic fields, which the source is current.
• A time-varying magnetic fields induce voltage in any conductor linked by the fields.
• Inductance is the circuit parameter which relates the induced voltage to the current.

Series inductances

• The equivalent inductance of N series-connected inductors is the sum of the individual inductances.

Parallel inductances

• The equivalent inductance of series-connected inductors is the reciprocal of the sum of the reciprocals of the individual inductances.