1. What is the BLDC Motor Speed Equation?

The BLDC (Brushless DC) motor speed equation calculates the rotational speed of a motor based on the input voltage and the motor's Kv rating. The Kv rating indicates how many RPM the motor will turn per volt applied (with no load).

2. How Does the Calculator Work?

The calculator uses the BLDC motor speed equation:

Where:

• \( V \) — Input voltage (volts)
• \( Kv \) — Motor velocity constant (RPM per volt)

Explanation: The equation shows that motor speed is directly proportional to the applied voltage when multiplied by the motor's Kv rating.

3. Importance of RPM Calculation

Details: Knowing the expected RPM of a BLDC motor is crucial for selecting the right motor for an application, predicting performance, and ensuring the motor operates within its designed parameters.

4. Using the Calculator

Tips: Enter the input voltage in volts and the motor's Kv rating (found in motor specifications). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Is this the actual speed under load?
A: No, this calculates no-load speed. Actual speed under load will be lower due to factors like torque requirements and efficiency losses.

Q2: What's a typical Kv range for BLDC motors?
A: Kv values range from <100 RPM/V for high-torque motors to >1000 RPM/V for high-speed applications.

Q3: Does battery voltage affect motor speed?
A: Yes, higher voltage increases speed proportionally, but must stay within motor's maximum rated voltage.

Q4: How accurate is this calculation?
A: It provides theoretical no-load speed. Real-world factors like voltage sag, temperature, and load affect actual speed.

Q5: Can I use this for brushed DC motors?
A: The same principle applies, but brushed motors typically have lower Kv ratings and different performance characteristics.