1. What is the DC Motor Current Formula?

The DC motor current formula calculates the current drawn by a DC motor when you know its power consumption and operating voltage. It's derived from the basic electrical power equation P = VI.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

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

Explanation: The formula shows that current is directly proportional to power and inversely proportional to voltage.

3. Importance of Current Calculation

Details: Knowing the current draw is essential for selecting proper wire gauges, circuit breakers, power supplies, and for thermal management of the motor and driver circuits.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: Is this formula valid for all DC motors?
A: This gives the theoretical current based on input power. Actual current may vary due to efficiency factors, startup surges, and mechanical load.

Q2: What's the difference between input and output power?
A: Motors aren't 100% efficient. The formula uses input power (electrical). Output power (mechanical) would require knowing the motor's efficiency.

Q3: How does this relate to Ohm's Law?
A: Ohm's Law (I = V/R) works with resistance. This formula works when you know power but not necessarily resistance.

Q4: Can I use this for AC motors?
A: No, AC motor calculations need to account for power factor and phase differences.

Q5: What if my motor has variable load?
A: This gives steady-state current. Startup currents can be 5-10x higher, and variable loads will cause current fluctuations.