1. What is the Torque Equation of a DC Motor?

Definition: This equation calculates the torque produced by a DC motor based on its torque constant, armature current, and magnetic flux.

Purpose: It helps electrical engineers and technicians understand and predict motor performance characteristics.

2. How Does the Torque Equation Work?

The equation is:

Where:

• \( T \) — Torque produced (lb-ft)
• \( K_t \) — Torque constant (lb-ft/A·Wb)
• \( I \) — Armature current (amps)
• \( \Phi \) — Magnetic flux (Weber, Wb)

Explanation: The torque is directly proportional to both the armature current and the magnetic flux, scaled by the motor's torque constant.

3. Importance of Torque Calculation

Details: Accurate torque calculation is essential for motor selection, performance analysis, and ensuring proper operation of mechanical systems.

4. Using the Calculator

Tips: Enter the torque constant (specific to each motor), armature current, and magnetic flux. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the torque constant (Kₜ)?
A: It's a motor-specific value that relates current and flux to torque output, typically provided in motor specifications.

Q2: How do I measure armature current?
A: Use an ammeter in series with the motor's armature circuit while operating under load.

Q3: What affects magnetic flux in a DC motor?
A: Flux depends on field current (in wound-field motors) or permanent magnet strength (in PMDC motors).

Q4: Why does torque increase with current?
A: More current creates stronger magnetic forces between the armature and field, producing greater torque.

Q5: How does this relate to motor power?
A: Power (in horsepower) can be calculated from torque and RPM using: HP = (T × RPM) / 5252