Component Symbols&

Information

Prof. Dr. Moustafa M. MohamedVice Dean, Faculty of Allied Medical Science,

Pharos University in Alexandria

Connectors

• Connectors – Termination devices for wires or cables.

• Plug = Probe = Male Contact.• Jack = Receptacle = Female Contact.

Connectors (cont.)

Types• 1/8” or ¼” DIN/guitar style

• RCA or phono style

• Terminal Block

• PC Board Edge Card

• Banana Style

• Power/wall plug style

Connectors (cont.)

Graphic Symbols• Generic Plug

• 1/8” – ¼” DIN plug

• RCA/Phono Plug

• Generic Jack

• 1/8”-1/4” DIN Jack

• RCA/Phono Jack

Connectors (cont.)

Lead Styles• Wire Lead• Eyelet• PC-Mount

Connectors (cont.)

Values/Ratings• Amperage• Voltage• Insulation/breakdown factors

• Reference Designation: – Jacks = J– Plugs/probes = P

Conductors and Cables

• Conductors and Cables - Used to make connections

Conductors and Cables (Cont)

Types• Hookup Wire – Solid, stranded• Coaxial Cable – Shielded, unshielded• Twisted Pair – Shielded, unshielded• Multiconductor Cables – Round, flat, shielded,

unshielded

Conductors and Cables (Cont.)

Value/Ratings• Amperage• Voltage• Insulation/Breakdown properties

• Reference Designation = W

Voltage Sources

• Direct Current (DC)– Types• Battery

– Single-cell

– Multi-cell

– Values/Ratings• Voltage• Ampacity

– Amps/hour– CCA

Voltage Sources (Cont)• Alternating Current (AC)– Types

• Generator

• Transformer

– Values/Ratings• Voltage• Amperage

• Reference Designation:– E or V– I

Protection Devices

• Protection Devices – Used to protect circuits from excess current flow

Protection Devices (Cont.)

Types• Fuses– Slow Blow– Fast Blow

• Circuit Breakers– Slow or fast blow– Manual– Thermal– Magnetic

Protection Devices (Cont.)

Lead Styles• Wire

• Eyelet

• Cartridge Ends

• Cartridge Tabs

Protection Devices (Cont.)

Values/Ratings• Current Limits• Voltage Applications

• Reference Designation:– Fuses = F– Circuit Breakers = CB

Protection Devices (Cont.)

Graphic Symbols• Fuse

• Circuit Breaker

Input Devices

• Input Devices – Used to input a signal to a circuit

Input Devices (Cont.)

Types• Antennas

• Microphones

• Sensors

• Connectors

Input Devices (Cont.)

Lead Styles• Wire• Eyelet• PC-Mount• Surface Mount• Cartridge Ends

Input Devices (Cont.)

Values/Ratings• Resistance/Impedance• Frequency• Voltage• Current• Sensitivity

• Reference Designation:– Antenna = E– Microphone = MK

Input Devices (Cont.)

Graphic Symbols• Antennas

• Microphone

Output Devices

• Output Devices – Used to display or produce circuit output signals

Output Devices (cont.)

Types• Displays– CRT– LED– LCD

• Drivers– Tape Heads– Loud Speakers– Piezoelectric cells– Buzzers– Bells

Output Devices (Cont.)

Values/Ratings• Resolution• Brightness• Wattage• Decibels• Frequency

• Reference Designation:– Displays: CRT, LED, LCD– Drivers: LS, DS

Output Devices (Cont.)

Graphic Symbols• Cathode Ray Tube

• Loud Speaker

Ground Connections

• Ground Connections – Used for common circuit return connections.

Ground Connections (Cont)

Types• Earth

• Chassis

• Common

Schematic Diagram Drafting Guidelines (Cont.)

Suggested Steps (Cont.)• Review/Revise the rough draft– Signal flow– Components:

• Symbols• Polarities• Values

– Connections– Notes

• Create Final Draft

Drafting Suggestions

• Allow for balance, and spacing considerations when placing individual components.

• Allow space for reference designations when placing individual components.

Schematic Diagram Construction Steps

• Layout inputs on left, and outputs on right. Sketch main components (Transistors, I.C.’s), then

• Sketch support components (Resistors, capacitors), and finally

• Sketch coupling components (Capacitors, diodes)• Sketch supply connections and input/output

connections.• Sketch horizontal and vertical interconnection lines.– Use minimal bends/dog legs.– Use minimal crossovers.– Use uniform spacing.

Schematic Diagram Construction Steps (Cont.)

• Sketch reference designations (required)– Use standard reference designations.– Label to the right or above component.

• Sketch Component values (optional)• Nominal rating• Tolerance• Power rating

• Review, revise, finalize

Schematic DiagramDo’s and Don’ts

Reading Schematic Diagrams

Troubleshooting with Schematic Diagrams