A schematic is a diagram that represents an electrical or mechanical system. It shows how a circuit functions and is used as a roadmap. Common symbols in schematics represent components like resistors, capacitors, diodes, transistors, batteries, switches, and logic gates. Understanding what each symbol means allows the schematic to show how current flows through the entire circuit.

1. SCHEMATICS
Basic Electronics Refresher
By
Chris Franckowiak

2. WHAT ARE SCHEMATICS?
A schematic is a structural or procedural diagram, especially of an electrical or
mechanical system.
schematic. (n.d.) The American Heritage® Dictionary of the English Language,
Fourth Edition. (2003). Retrieved June 25 2012 from
http://www.thefreedictionary.com/schematic

3. SCHEMATICS
• Used to graphically represent what a circuit is doing and how it is functioning.
• An atlas or roadmap of an electrical circuit

4. COMMON SYMBOLS
• The following slides look at some of the most common symbols found in electrical
schematics
• Not all-inclusive – many others used

5. RESISTORS
• Fixed Resistor • Variable Resistor (Pods)
• A resistor is part of an electrical circuit that resists the flow of current
• Measured in Ohms after Ohms Law
• Ohms Law: I (current) = V (Voltage) / R (Resistance)

6. INDUCTORS
• Air Core Inductor • Variable Inductor
• A passive electrical component that stores energy in its magnetic field
• Also known as coils and chokes
• Used in analog circuits and signal processing

7. CAPACITORS
• A passive electrical component used to store energy in an electric field
• Used to block DC while allowing AC to pass (filter)
• Smoothing outputs of power supplies

8. DIODES
General Gunn
• Many types (Zener, Avalanche, Gunn, IMPATT)
• Low resistance to current flow in one direction and high (indefinite) resistance in the other
direction
• Used in rectifiers

9. COMMON SYMBOLS
• Tie Points
• Tie Points show things that are connected
• Considered a path

10. GROUND
Earth Chassis
• Different types of grounds
• Earth ground tied to earth
• Chassis ground tied to common ground on the circuit/equipment

11. CONDUCTORS
• Tie Points and overlapping lines
• How current reaches individual components (resistors, capacitors, etc..)

12. SWITCHES
• Many, many types
• Classified by poles, throw
• Used to redirect current flow

13. TRANSISTORS
• Many different types
• Used to amplify and switch electronic signals

14. BATTERY
• Power supplies
• DC, AC

15. INDUCTORS
• Known as chokes, coils
• Stores energy in its electrical field
• Many types as well

16. GATES
• Logic gates
• And, OR, NAND, NOR, NOT, XOR, XNOR
• Can be used to store data

17. CONCLUSION
• Symbols represent how the circuit functions
• Many slides could be made for each component (this is just a review of what you will see)
• By knowing what each one is and how they work – schematics become very familiar
• It is a learning process