1. What is a Motor Resistance Calculator?

Definition: This calculator determines the electrical resistance of a motor based on Ohm's Law, using voltage and current measurements.

Purpose: It helps engineers, technicians, and hobbyists quickly calculate motor resistance for diagnostics, circuit design, and troubleshooting.

2. How Does the Calculator Work?

The calculator uses Ohm's Law formula:

Where:

• \( R \) — Resistance (Ohms, Ω)
• \( V \) — Voltage across motor (Volts, V)
• \( I \) — Current through motor (Amperes, A)

Explanation: The voltage measured across the motor is divided by the current flowing through it to determine its resistance.

3. Importance of Motor Resistance Calculation

Details: Knowing motor resistance helps in:

• Determining power consumption
• Diagnosing motor health
• Designing proper electrical circuits
• Calculating heat dissipation

4. Using the Calculator

Tips:

• Measure voltage across motor terminals
• Measure current in series with motor
• Ensure motor is not running (for DC resistance measurement)
• All values must be > 0

5. Frequently Asked Questions (FAQ)

Q1: Is this AC or DC resistance?
A: This calculates DC resistance. For AC motors, you'll need impedance calculations.

Q2: Why does my motor show different resistance when running?
A: Running motors have back EMF and inductive reactance that affect measurements.

Q3: What's a typical motor resistance range?
A: Small motors (1-100Ω), medium (0.1-10Ω), large (0.01-1Ω) - varies by power rating.

Q4: How accurate is this calculation?
A: Accuracy depends on your voltage and current measurement precision.

Q5: Does temperature affect resistance?
A: Yes, resistance increases with temperature (positive temperature coefficient).