Back EMF: Why a Stalled Motor Burns Out

A spinning motor is also a generator. The faster it turns, the more voltage it makes against the supply, and that back EMF is what limits the current. Stall it, and the current is limited by nothing but the winding resistance.

The video shows why a motor draws the most current at zero speed, why that heats it, and how the constant Kv ties speed, voltage and torque together.

In this video

• Why a motor generates voltage while it runs
• Stall current and why it's dangerous
• Kv, Kt and the speed–torque line
• What the controller sees when the load changes