1. Chapter 27Electrical/Electronic Drawings Michael W. Choroneko Upper Darby High School Technology Education Department

2. Electrical/Electronic Drawing Types • Connection Diagrams • Schematic (Elementary) Diagrams • Printed Circuit Drawings • Block and Logic Diagrams

3. Connection Diagrams

4. Connection Diagrams • Intended for do-it-yourself manuals and building kits • Shows the external electrical connections of the various parts

5. Schematic Diagrams

6. Schematic Diagrams • show electrical connection and function of a circuit using graphic symbols • also known as elementary diagram • symbols are used to represent electronic components

7. What is the purpose of a schematic diagram and describe the features that are included in it. • A schematic diagram shows the electrical connection and function of a circuit. • It features lines for wires, symbols for components, and values describing each component.

8. Printed Circuit Board Drawings

9. Printed Circuit Board Drawings • Used to create thin ribbons of copper formed on plastic board • Involves the planning for a component’s size using lands and connectors

10. Block & Logic Diagrams

11. Block & Logic Diagrams • Used by designers in the early stages of planning a project • Consists of boxes and triangles showing a plan in its conceptual form

12. Shows electrical connection and function of a circuit using graphic symbols Involves the planning for a component’s size using lands and connectors Used by designers in the early stages of planning a project Also known as elementary diagrams Connection Schematic Printed Circuit Block & Logic Electrical Drawing Type Match

13. Intended for do-it-yourself manuals and building kits Shows the external electrical connections of the various parts Consists of boxes and triangles showing a plan in its conceptual form Used to create thin ribbons of copper formed on plastic board Connection Schematic Printed Circuit Block & Logic Electrical Drawing Type Match

14. Symbols such as are used to represent electronic components Connection Schematic Printed Circuit Block & Logic Electrical Drawing Type Match

15. Electronic Components of the SchematicDiagramBasic Theory of Operation & Symbols

16. Transistor A transistor may be used as a switch (either fully on with maximum current, or fully off with no current) and as an amplifier (always partly on). Transistors amplify current, for example they can be used to amplify the small output current from a logic chip so that it can operate a lamp, relay or other high current device.

17. Transistor • Replaced the vacuum tube • Electronic switch or amplifier • Became a household name with the transistor radio

18. Battery • A battery is essentially a can full of chemicals that produce electrons. 6 - 1.5 volt cells

19. Battery • Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal

20. Fuse • A protective device containing a calibrated current carrying member which melts and opens a circuit under specified over current conditions

21. Diode • Diodes allow electricity to flow in only one direction. The arrow of the circuit symbol shows the direction in which the current can flow. • Diodes are the electrical version of a check valve.

22. Light Emitting Diode (LED) • LEDs emit light when an electric current passes through them 

23. Transformer • Used to step up or step down voltage 

24. Transformer • Uses wire wraps to alter voltage by capturing collapsing magnetic fields 

25. Transformer with built-in bridge rectifier Diodes

26. Resistor • Resistors restrict the flow of electric current  • Resistors are an electron filter allowing a measured amount of electrons to pass through • Resistance is measured in Ohms ON TEST

27. Potentiometer (Variable Resistor) • The amount of Resistance can be changed • Used for volume control, etc. • Operation is similar to a globe valve

28. Capacitor • Capacitors store energy by maintaining a charge difference between two plates separated by an insulator.  • They then release the power all at once ON TEST

29. Capacitor • A capacitor can store electrical energy and deliver it when needed.   • For example, in a photoflash camera a capacitor is charged slowly with a small current, and then connected to the flash bulb.  The capacitor discharges quickly, sending a high current through the flash bulb.

30. Stun Gun (capacitors and transformers in action) • The batteries supply electricity to a circuit consisting of various electrical components. • The capacitor builds up a charge, and releases it to the electrodes, the "business end" of the circuit.

31. Stun Gun • The circuitry includes multiple transformers, components that boost the voltage in the circuit, typically to between 20,000 and 150,000 volts, and reduce the amperage. It also includes a oscillator, a component that fluctuates current to produce a specific pulse pattern of electricity. This current charges a capacitor. The capacitor builds up a charge, and releases it to the electrodes.

32. Another name for a chip, an integrated circuit (IC) is a small electronic device made out of a semiconductor material. Integrated Circuit (IC)

33. The first integrated circuit was developed in the 1950s by Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor. Integrated Circuit (IC)

34. Integrated circuits are used for a variety of devices, including microprocessors, audio and video equipment, and automobiles. Integrated Circuit (IC)

35. Integrated circuits are often classified by the number of transistors and other electronic components they contain. • Integrated circuits are an all-in-one component containing micro versions of transistors and other electronic components ON TEST Integrated Circuit (IC)

36. SPST Switch(Single Pole, Single Throw) Manual ON/OFF switch Opens and closes circuit by contact (open = OFF) (closed = ON)

37. SPDT Switch(Single Pole, Double Throw) • 2 position switch (this or that) • AM/FM switch • Hallway switch

38. PBNO Switch(Push Button, Normally Open) • Switch closes circuit when pressed, opens when released • Example: Doorbell

39. PBNC Switch(Push Button, Normally Closed) • Switch opens circuit when pressed, closes when released • Example: re-set button

40. Electrical Terms & ConceptsBasic Theory

41. Capacitance • This is a measure of a capacitor's ability to store a charge. ON TEST • A large capacitance means that more charge can be stored.

42. Capacitance • Capacitance is measured in FARIDS, symbol F. However 1F is very large, so prefixes are used to show the smaller values ON TEST • The three prefixes (multipliers) used are: µ (micro), n (nano) and p (pico)

43. Resistance In an electrical circuit, the ability to restrict the flow of electrons is called resistance, and it is measured in ohms. Ohm’s Law = (R) Resistance ON TEST

44. Pressure / Voltage The "pressure" pushing the electrons along is called the voltage and is measured in volts. ON TEST Ohm’s Law = (E) Electromotive Force

45. Current / Amperage In an electrical circuit, the number of electrons that are moving is called the amperage or the current, and it is measured in amps. ON TEST Ohm’s Law = (I) Intensity

46. - Polarity + • Positive (+) or Negative (-) • Electrons flow from negative to positive ON TEST - +

47. AC/DC Current NO! Not that AC/DC!

48. DC Current direct current (DC) • Batteries, fuel cells and solar cells all produce something called direct current (DC). ON TEST

49. DC Current • The terminals of a battery are always positive & negative • Current always flows in the same direction between those two terminals

50. AC Current + • The power that comes from a power plant is called alternating current • AC current alternates from positive to negative in a wave form ON TEST -