Electrical Drawings

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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 Diagrams
• Represents the actual wiring between component
  devices in
• electrical equipment. Shows internal or external
  connections, or
• both. Wiring Harness Diagram
• Logic Diagrams
• Shows 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 Diagrams
Point-to-Point diagram
Wire color codes

• 0. Black (BK)
• Brown (BN)
• Red (RD)
• Orange (OR)
• Yellow (YL)
• Green (GN)
• Blue (BL)
• Violet (VI)
• Gray (GY)
• White (WH)

Each wire is shown by a separate line.
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Wiring Diagrams
Baseline diagram
Wire lines from components are terminated into
common baselines.
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Wiring Diagrams
Highway 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 Diagrams
Logic Gates
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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 Drawing Used to cut the board edges
and to locate the feed-through holes for drilling
.
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Printed Circuit Board Drawings (PCBs)
Silkscreen Drawing Lettering and component
outlines are printed on the board.
Assembly Drawing Shows 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 Equipment
• MIL - STD 681 Identification Coding and
  Application of Hook Up and Lead Wire
• MIL - STD 1495 Multi-layer Printed Wiring
  Boards for
• Electronic Equipment
• Underwriters Laboratory (UL) - Safety codes
  consideration