동영상

• ▶ Electricity Basics Ep.20 – Why use 3 phase?｜Audio Book ｜ Easy to listen to! 전병칠 · 2025.08.26
• ▶ Electricity Basics Ep.19 – What is a phase?｜Audio Book ｜ Easy to listen to! 전병칠 · 2025.08.24