変圧器は何ワット必要？

資料が裏付ける範囲

各資料が裏付けるのは記載された事実、プラグ形式、機種のみです。機種の例はカテゴリ全体の確認にはなりません。実際のラベルとコンセントを確認してください。

1. OpenStax: Power in an AC Circuit, section 15.4 · 確認: 2026-09-04

   For sinusoidal AC, average real power is RMS voltage times RMS current times the power factor. Multiplying the RMS voltage and current alone does not necessarily give real watts. Power factor discussion and RMS average-power equation before Example 15.3. An electrical principle, not a measured power factor, startup demand or converter approval for any appliance. Use manufacturer ratings for the actual load.

2. SKROSS: World to USB series manual, version 1.2 · 確認: 2026-09-04

   AC current limits and USB output are separate. In the AC20PD examples a single USB-C port reaches about 20W; simultaneous USB-A + USB-C use shares 15W. PDF page 1, English technical ratings and safety instructions. These figures apply to the named series. The manual prohibits stacking adapters and multiplug sockets; other models require their own manual.

3. Conair: 1875 W Model 303 hair dryer instructions · 確認: 2026-08-21

   Conair Model 303 specifies 110–125V AC, 60Hz and prohibits use with a voltage converter. PDF page 1, important safety and operating instructions. This label excludes Japan’s 100V. It does not describe every hair dryer.

変圧器容量の例

W × 1.25はPlugVoltageの概算で、変圧器の適合条件を検証した値ではありません。起動時電力、許容負荷、使用時間を双方のメーカーに確認してください。電圧が合わない高出力の発熱機器への変圧器使用は推奨しません。