What types of loads are known to cause harmonic distortion?

Harmonic distortion occurs when non-linear loads draw current in a non-sinusoidal manner, resulting in the generation of harmonics. Various devices in electrical systems can create these non-linear loads, and examples include LED lighting, computers, and electronic ballasts.

LED lighting often uses switching power supplies that convert AC to DC power. This conversion process can lead to harmonic generation due to the abrupt changes in current. Similarly, computers utilize power supplies that can also generate harmonics when they convert the input AC to the necessary DC voltages required for operation. Electronic ballasts, which are used to control fluorescent lighting, similarly exhibit non-linear characteristics, as they regulate current flow through pulsed control methods, resulting in harmonic distortion.

Since LED lighting, computers, and electronic ballasts are all capable of producing harmonics due to their design and operational characteristics, it is accurate to say that all of these types of loads contribute to harmonic distortion. Thus, the comprehensive nature of the correct answer captures the full scope of devices known to cause such distortion.