1 / 18

Introduction to Energy Storage Elements: The Capacitor

Introduction to Energy Storage Elements: The Capacitor. Review. So far, we have talked about two kinds of circuit elements: Sources (independent and dependent)- active, can provide power to the circuit. Resistors-passive, can only dissipate power. Energy Storage Elements.

wanda
Download Presentation

Introduction to Energy Storage Elements: The Capacitor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Energy Storage Elements:The Capacitor Lecture 10

  2. Review • So far, we have talked about two kinds of circuit elements: • Sources (independent and dependent)- active, can provide power to the circuit. • Resistors-passive, can only dissipate power. Lecture 10

  3. Energy Storage Elements • Capacitors store energy in an electric field. • Inductors store energy in a magnetic field. • Capacitors and inductors are passive elements: • Can store energy supplied by circuit • Can return stored energy to circuit • Cannot supply more energy to circuit than is stored. Lecture 10

  4. Energy Storage is Fun! • Voltages and currents in a circuit without energy storage elements are linear combinations of source voltages and currents. • Voltages and currents in a circuit with energy storage elements are solutions to linear, constant coefficient differential equations! Lecture 10

  5. Even More Fun! • Practicing engineers almost never solve the differential equations directly. They also almost never use the techniques in Chapter 6. • Instead, they use: • LaPlace transforms (covered in EEE 302) • AC steady-state analysis • These techniques convert the solution of differential equations into algebraic problems-circuit analysis (eg the voltage divider) can be applied directly. Lecture 10

  6. Power Generation and Distribution • Energy storage elements model electrical loads: • Capacitors model computers and other electronics (power supplies). • Inductors model motors. Lecture 10

  7. Signal ProcessingCommunicationInstrumentation • Capacitors and inductors are used to build filters and amplifiers with desired frequency responses: • RF and IF amplifiers in a superhetrodyne receiver. • Instrumentation amplifiers. Lecture 10

  8. Signal ProcessingCommunicationInstrumentation • Capacitors are used in A/D converters (PCM encoders) to hold a sampled signal until it can be converted into bits. Lecture 10

  9. Solid StateDigital Design • Integrated circuits have layers of conductors (metal, silicon with impurities) with insulators (glass) between. This is a capacitor! • This capacitance is one of the limiting factors in processor speeds. • This capacitance is used to create RAM’s. Lecture 10

  10. Electromagnetics • For high frequency signals, inductance and capacitance are more significant effects than resistance. Lecture 10

  11. Capacitance • Capacitance occurs when two conductors (plates) are separated by a dielectric (insulator). • Charge on the two conductors creates an electric field that stores energy. • The voltage difference between the two conductors is proportional to the charge: q = C v Lecture 10

  12. Capacitance • The proportionality constant C is called capacitance. • Units of Farads (F) - C/V Lecture 10

  13. The rest of the circuit + i(t) v(t) - Capacitor Lecture 10

  14. Capacitor Voltage Lecture 10

  15. Energy Stored Lecture 10

  16. i(t) 1A 2s -1A t 1s Example i(t) The rest of the circuit + 0.2F v(t) - Lecture 10

  17. Find v(t)Find wc(t) Lecture 10

  18. v(t) 5V 2s 1s t Solution wc(t) 2.5J 2s 1s t Lecture 10

More Related