1. What is the Electric Power Equation?

The basic power equation (P = V × I) calculates electrical power in watts from voltage and current. This fundamental relationship is essential for understanding and designing electrical systems, particularly for DC motors.

2. How Does the Calculator Work?

The calculator uses the power equation:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)

Explanation: The equation shows that electrical power is the product of voltage and current. For AC systems, power factor must also be considered.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for selecting proper motor sizes, determining energy consumption, and designing electrical circuits that won't be overloaded.

4. Using the Calculator

Tips: Enter voltage in volts and current in amps. Both values must be positive numbers. The calculator will compute the power in watts.

5. Frequently Asked Questions (FAQ)

Q1: Is this equation valid for AC motors?
A: For AC systems, you need to include power factor (P = V × I × PF). This calculator is for DC systems only.

Q2: What are typical voltage ranges for motors?
A: Common voltages include 12V, 24V (automotive), 120V, 230V (household), and 400V+ for industrial applications.

Q3: How does this relate to motor efficiency?
A: The calculated power is electrical input power. Mechanical output power depends on motor efficiency (typically 70-95% for good motors).

Q4: What about three-phase power?
A: Three-phase power requires a different calculation: P = √3 × V × I × PF.

Q5: How do I convert watts to horsepower?
A: 1 horsepower ≈ 746 watts. Divide wattage by 746 to get horsepower.