Component Symbols & Information Prof. Dr. Moustafa M. Mohamed Vice 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–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 Diagram Dos and Donts

Reading Schematic Diagrams

Troubleshooting with Schematic Diagrams