变压器需要多少瓦？

证据支持的范围

来源仅支持下列事实、插头类型或型号。型号示例不能证明整个设备类别。请核对自己的标签和实际插座。

1. OpenStax: Power in an AC Circuit, section 15.4 · 核查日期: 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 · 核查日期: 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 · 核查日期: 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.

变压器功率示例

瓦数 × 1.25是PlugVoltage的估算，并非经验证的变压器要求。请与双方制造商确认启动需求、允许负载和使用时长。我们不建议对电压不匹配的高功率发热设备使用旅行变压器。