วิธีการคำนวณ Watts to Amps
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A watts to amps converter calculates electrical current from power and voltage using Ohm's law. It is used for sizing circuit breakers, fuses, and cables for electrical installations.
สูตร
A (DC) = W / V; A (AC) = W / (V × PF)
- W
- Power (W) — Electrical power in watts
- V
- Voltage (V) — Electrical potential difference in volts
- A
- Current (A) — Electrical current in amperes
- PF
- Power factor ((dimensionless)) — AC circuits only; typically 0.8–1.0
คำแนะนำทีละขั้นตอน
- 1Amps = Watts ÷ Volts (DC circuits)
- 2Amps = Watts ÷ (Volts × Power Factor) (AC circuits)
- 3Standard voltages: 120V (US), 230V (UK/EU), 240V (AU)
- 4Power factor for resistive loads = 1.0
ตัวอย่างที่มีคำตอบ
อินพุต
2400W appliance at 240V
ผลลัพธ์
10 amps
อินพุต
1200W microwave at 120V
ผลลัพธ์
10 amps
อินพุต
3000W oven at 240V
ผลลัพธ์
12.5 amps
คำถามที่พบบ่อย
What is the difference between watts and amps?
Watts measure power (energy per unit time). Amps measure current flow. Relationship: Watts = Volts × Amps.
Why do I need to know this?
For sizing circuit breakers, fuses, and electrical cables. An undersized wire can overheat; an incorrectly rated breaker won't protect the circuit.
What is power factor?
In AC circuits, power factor accounts for reactive loads (motors, inductors). A pure resistive load has PF = 1.0. Motors typically have PF = 0.8–0.95.
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