Electronics 01
Why Is Three-Phase Power Used? The Real Reasons
Three-phase power delivers constant power and a rotating field for motors. The copper saving is real but depends on what you compare. Worked numbers here.
power grid
Electronics 02
Why Do Transformers Hum? It's 100 or 120 Hz, Not 50 or 60
Transformer hum comes from magnetostriction: the core stretches about 2 micrometres per metre twice every cycle. Why 100/120 Hz, and what makes it louder.
Electronics 03
Why Is Electricity Transmitted at High Voltage? The Math
Why is electricity transmitted at high voltage? We work the I²R loss for a real 345 kV line, show why 1,100 kV is about the ceiling, and when HVDC wins.
Electronics 04
Why Is AC Power 60 Hz (or 50 Hz)? The Real Tradeoffs
60 Hz came from an 1890 Westinghouse study of engines, lamps and transformers, not Tesla. The physics of transformer size, skin effect and line length.
Electronics 05
Why Don't Birds Get Electrocuted on Power Lines?
A bird on a live wire feels about 4 millivolts and 4 microamps. We work the numbers, bust the 'not grounded' myth, and show when birds really do die.