1 / 28

Electrical Circuits and Electronics

Electrical Circuits and Electronics.

sunnij
Download Presentation

Electrical Circuits and Electronics

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. Electrical Circuits and Electronics Literature:Chapman Stephen J.,  Electric Machinery Fundamentals, McGraw-Hill Publishing Company,  1985, ISBN 0-07-010662-2Crecraft D.I., Gorham D.A., Sparkes J.J., Electronics, Chapman&Hall 1993,ISBN 0-412-41320-5Rizzoni Giorgio, Principles and Applications of electrical Engineering, McGraw-Hill Publishing Company ISBN 0-256-26116-4Roadstrum William H., Wolaver Dan H., Electrical Engineering for All Engineers, John Wiley&Sons, Inc.,  ISBN 0-471-51043-2 Reading (Tu 8:00) – Doc. Ing. Jan Chyský, CSc Lab. Exercises (Tu 16:00) – Ing. Josef Vlček, CSc http://elektro.fsid.cvut.cz/en/

  2. First Part • Analysis of Electrical Circuits(Ohm’s law, Kirchhoff’s laws, loop and nodal analysis, principle of superposition. Thevenin’s and Norton theorems. Circuits supplied by DC andAC. Transient states in electrical circuits.

  3. Second Part • Electronics(Semiconductors, diodes, transistors, thyristors, operating amplifiers.Basic analogue and digital circuits)

  4. Electricity at work National Grid Serves for distribution of electrical energy from powerplants to consumers

  5. Distribution Systém

  6. AC and DC electricity • Voltage from batery is in one direction.Current flows from + lead to – lead • Voltage on coils terminal when the coil is turned in magnetic field.

  7. Single and 3 Phase Generator

  8. Delta connection

  9. Star connection One end of each phase coils is commonly linked to form a star or neutral point Voltage between any phase line and neutral is 1/sqrt(3) times that between any two phases phase/phase = 400 Vphase/line = 230 V

  10. Distribution

  11. Circuit protection Means of isolating supply Means of protection against axcess current Means of protection against earth leakage

  12. Circuit protection (2) Fuses and beakers must be accomodated to load.For motors should be used other fuses than for bulbs

  13. Personal protection • Preserve persons to injury by electric current.The injury causes current not voltage, but the voltage causes the current (Ohms law) I = V/R

  14. System earthing • Earth electrode • Earthing conductor • Protective conductor

  15. System earthing (2)

  16. System earthing (3) • TN-S systém Uses separate protective PE and neutral N conductor

  17. System earthing (4) • TN-C-S systém Uses common protective PE and Neutral conductor

  18. System earthing (5) • Earth leakage protection

  19. Safety of work Basic prescript - Law 50/1978 Sb Divides persons according their qualification §3 - Introduced workers §4 – Instructed workers (students in universities labotarory) Both paragraphs are valid for workers without electrotechnical educations

  20. Safety of work (2) Terminology Living parts (hot) serves for current conducting, or aro under voltage or parts are conected vith voltage Non-living are construction parts regulary without any voltage or current. Due to concern some voltage or current may be there there

  21. Safety of work (3) Incidence of electric curent on body

  22. AC 15-100Hz DC charge 1 mA 3 mA 0,5 mC parts which need NOT to be touch by personal during function 3,5 mA 10 mA 5O mC Magnitude of current, when it is not possible to release hand. Current causes paralysis, suffocation >25 mA >100 mA ---- Safety current

  23. Contact voltage Ud

  24. Safety voltage

  25. Protection against dangerous voltage • Using isolation of living parts • Basic isolation • Suplementary isolation • Double isolation • Using covering • Using barrier • Using position

  26. Protection against dangerous voltage • Additional protection with current protector • Additional isolation (insulated pads, glove, etc.)

  27. Protection using automatic disconnection in TN system • Uses fuse or circuit breaker for disconnecting power supply

More Related