The low voltage DC motor is an electric motor that runs on direct current (DC) power at relatively low voltages, typically below 100 V - common ranges include 6 V, 12 V, 24 V, and 48 V.

These motors are valued for compact size, safety, controllability, and efficiency in applications where high voltage is unnecessary or undesirable.

What is a Low Voltage DC Motor?

Low voltage DC motors have two main parts:

    1. Rotor (armature) - the moving part.

    2. Stator - the stationary magnetic field source.

They work by converting electrical energy from a low-voltage DC supply into mechanical energy, using the interaction between magnetic fields and current-carrying conductors. Reversing the polarity of the supply reverses the motor' s rotation.

What is low voltage for DC?

In the context of direct current (DC) systems, "low voltage" generally refers to voltages that are safe to handle under normal conditions and fall well below high-voltage electrical safety limits. Usually < 48-60 V DC for most low-voltage devices and motors, especially in consumer, automotive, and industrial control systems.

International and Electrical Standards

IEC (International Electrotechnical Commission) - In IEC 61140, low voltage DC is defined as up to 1500 V DC for general low-voltage installations, but this includes what many would consider medium voltages.

Extra-Low Voltage (ELV) - Often used in electronics and safety applications:

1. SELV (Safety Extra-Low Voltage): < 60 V DC under dry conditions.

2. PELV (Protective Extra-Low Voltage): Similar to SELV but with protective grounding.

3. FELV (Functional Extra-Low Voltage): Used for functional purposes without strict safety isolation.

Common practical engineering use: For small motors, electronics, and portable equipment, low voltage DC usually means 6 V, 12 V, 24 V, or 48 V.

Main Types of Low Voltage DC Motors

1. Brushed DC Motors

• Description: Use brushes and a commutator for mechanical switching.

• Advantages: Simple, low cost, high starting torque.

• Drawbacks: Brushes wear out, requiring periodic maintenance.

• Applications: Toys, small tools, automotive actuators.

2. Brushless DC Motors (BLDC)

• Description: Use electronic commutation instead of brushes.

• Advantages: High efficiency, long lifespan, quiet operation.

• Drawbacks: Higher initial cost, needs a controller.

• Applications: Drones, electric scooters, computer fans.

3. Coreless DC Motors

• Description: Rotor has no iron core, reducing inertia.

• Advantages: Fast acceleration, lightweight, low vibration.

• Applications: Medical devices, high-speed tools, robotics.

4. Geared DC Motors

• Description: Integrated gearbox to reduce speed and boost torque.

• Advantages: Compact, high torque at low speeds.

• Applications: Automation systems, conveyor belts, precision positioning.