Overview
This lecture explains the differences between alternating current (AC) and direct current (DC), where they are found in daily life, and how they are used in electronics.
Types of Electric Current
- There are two main types of current: alternating current (AC) and direct current (DC).
- AC is most commonly provided by wall outlets in homes and buildings.
- DC is most commonly provided by batteries.
Everyday Uses of AC and DC
- AC powers large appliances like refrigerators and electric stoves.
- DC powers electronic devices like cell phones, computers, and flashlights—anything that uses a battery.
- When charging devices like phones or laptops, the AC from the wall is converted to DC by the charger.
Conversion Between AC and DC
- Special electronic devices can convert AC to DC and vice versa.
- Phone and laptop chargers convert AC from the wall outlet to DC needed by the device batteries.
Main Differences Between AC and DC
- AC changes direction repeatedly and rapidly as it travels through a wire.
- DC moves in only one direction and never reverses.
- AC alternates direction many times per second, while DC current does not alternate.
Focus for This Course
- The course will primarily use DC, as most small electronic components require direct current.
- AC will be discussed occasionally, but emphasis is on DC for practical electronics work.
Key Terms & Definitions
- Alternating Current (AC) — Electric current that reverses direction periodically.
- Direct Current (DC) — Electric current that flows in one constant direction.
- Converter — An electronic device that changes AC to DC or vice versa.
Action Items / Next Steps
- Post any questions about AC or DC in the comments for clarification.
- Prepare to work mainly with DC in upcoming lessons.