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Electrical Drawings

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Types of Electronic Diagrams • Schematic Diagrams

Using graphic symbols, shows the electrical connections and

functions of a specified circuit arrangement.

• Wiring DiagramsRepresents the actual wiring between component devices in

electrical equipment. Shows internal or external connections, or

both. Wiring Harness Diagram

• Logic DiagramsShows logic gates and components.

• Printed Circuit Board Drawing (PCB)PC boards replace hand-wiring manufacturing methods.

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Schematic Drawings

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Wiring DiagramsPoint-to-Point diagram Wire color codes

0. Black (BK)

1. Brown (BN)

2. Red (RD)

3. Orange (OR)

4. Yellow (YL)

5. Green (GN)

6. Blue (BL)

7. Violet (VI)

8. Gray (GY)

9. White (WH)

Each wire is shown by a separate line.

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Wiring DiagramsBaseline diagram

Wire lines from components are terminated into common baselines.

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Wiring DiagramsHighway diagram

The feeder lines from component terminals are merged into a single highway.

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Wiring Diagrams

Wiring harness Cabling diagram

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Logic DiagramsLogic Gates

Logic circuits are used for controlling electronic devices.

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Printed Circuit Board Drawings (PCBs) Schematic Drawing Provides the basis of a circuit board. Logic diagram is used for

integrated circuits.

Artwork Drawing – Component side Artwork drawings are used to create the mask that will actually create the

etched circuit. The component side artwork shows the circuitry that will be

etched on the same side as the circuit components.

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Printed Circuit Board Drawings (PCBs)

Artwork Drawing – Circuit side

The side where most of the circuit connections are made

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Printed Circuit Board Drawings (PCBs)

Fabrication DrawingUsed to cut the board edges and to locate the feed-through holes for drilling .

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Printed Circuit Board Drawings (PCBs)

Silkscreen DrawingLettering and component outlines are

printed on the board.

Assembly DrawingShows how components are mounted before being soldered, and it is used by manufacturing to ensure proper assembly of the

components.

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Printed Circuit Board Drawings (PCBs)

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Sources of Standardized Codes and Symbols • ANSI - American National Standards Institute - Graphic Symbols for

Electrical and Electronic Diagrams - ANSI / IEEE• Government standard for military contractors

MIL - STD – 275 Printed Wiring for Electronic Equipment

MIL - STD – 429 Printed Wiring and Printed Circuits –Terms and Definitions

MIL - STD – 454 Standard General Requirements for Electronic EquipmentMIL - STD – 681 Identification Coding and Application of

Hook Up and Lead WireMIL - STD – 1495 Multi-layer Printed Wiring Boards for

Electronic Equipment

• Underwriters’ Laboratory (UL) - Safety codes & consideration