1. What is Input Power?

Input power (P_in) is the electrical power required by a motor to produce a certain mechanical output power (P_out). The relationship between input and output power is determined by the motor's efficiency (η).

2. How Does the Calculator Work?

The calculator uses the input power formula:

Where:

• \( P_{in} \) — Input power (watts)
• \( P_{out} \) — Output power (watts)
• \( \eta \) — Efficiency (decimal between 0 and 1)

Explanation: The formula shows that input power equals output power divided by efficiency. Higher efficiency means less input power is needed for the same output.

3. Importance of Input Power Calculation

Details: Calculating input power is essential for sizing electrical systems, determining energy consumption, and evaluating motor performance. It helps in selecting appropriate power supplies and estimating operating costs.

4. Using the Calculator

Tips: Enter output power in watts and efficiency as a decimal (e.g., 0.85 for 85%). Efficiency must be between 0.01 and 1.00.

5. Frequently Asked Questions (FAQ)

Q1: What is typical motor efficiency?
A: Efficiency varies by motor type and size. Small motors might be 60-80% efficient, while large industrial motors can reach 95% efficiency.

Q2: How does efficiency affect input power?
A: Lower efficiency requires more input power for the same output. For example, at 50% efficiency you need twice the input power compared to 100% efficiency.

Q3: Can I use this for generators?
A: Yes, the same principle applies to generators where P_out would be electrical power and P_in would be mechanical input power.

Q4: What units should I use?
A: The calculator uses watts for power. For horsepower, convert to watts first (1 HP ≈ 746 watts).

Q5: Why is my calculated input power higher than output?
A: This is normal since efficiency is always less than 1. The difference represents energy lost as heat, noise, and vibration.