Electrical Current - Engineering Mindset

Introduction

• Paul from Engineering Mindset
• Overview: Understanding electrical current, types, symbols, measurement, and safety devices

Basic Concepts

• Electrical Current: Flow of electrons in a circuit
  • Requires electrons to flow in the same direction
• Copper Wire: Common conductor due to loosely bound electrons
  • Rubber Insulators: Prevent free electron movement, ensuring safety
• Voltage: Pushing force like pressure in a water pipe
  • Measures without current flow; similar to measuring pressure without water flow

Measuring and Safety

• Amperes (Amps): Unit for measuring flow of electrons (current)
  • Example: Fuse labeled "3A" handles 3 amps
• Random Movement vs. Forced Movement: Random movement not a current; battery forces directed flow
• Current Measurement Devices: Ammeter and multimeter

Electron Flow vs. Conventional Current

• Conventional Current: Franklin's positive-to-negative theory; still used
• Electron Flow: Thompson’s discovery of actual negative-to-positive electron movement
• Impact: Engineering formulas remain accurate regardless of flow direction

AC vs. DC

• Alternating Current (AC): Electrons alternate directions (e.g., home power supply)
• Direct Current (DC): Electrons flow in one direction (e.g., electronics)
• **Conversion Devices: **Rectifiers (AC to DC) and Inverters (DC to AC)

Practical Aspects

• Device Labels: Indicate voltage and current needs (e.g., laptop chargers)
• Circuits: Series vs. Parallel: Impact on electron flow and current measurement
• Resistors: Control current by adding resistance

Detailed Measurement Example

• Lamp and Battery Example: Explains current, electrons per second, and impact of resistance
• Multimeter Usage: Demonstrates measuring current through circuit components
• Thermal Imaging: Shows heat dissipation from resistors

Fuses and Circuit Protection

• Fuses: Protect by burning out when over current occurs
• Circuit Breakers: Provide overload and short circuit protection
• Ground Fault Circuit Interrupter (GFCI/RCD): Cuts power during leakage or fault

Conclusion

• Summary of covered topics
• Encouragement to explore further resources and videos
• Mention of social media and website