/ˈrɛktɪfaɪər/

noun … “Circuit that converts alternating current to direct current.”

Rectifier is an electronic circuit or device that converts alternating current (AC) into direct current (DC). Rectification is a fundamental process in power electronics, allowing electrical systems and devices that require steady, one-directional current to operate using AC power sources such as wall outlets or generators. Rectifiers are built primarily using diodes, which enforce one-way current flow.

In operation, a Rectifier blocks portions of the AC waveform that flow in the undesired direction and passes the portions that flow in the desired direction. The resulting output is a pulsating DC signal, which is often smoothed using capacitors, inductors, or voltage regulators to produce a more stable DC supply.

Key characteristics of Rectifier include:

  • Direction control: converts bidirectional AC into unidirectional DC.
  • Diode-based design: relies on diode forward and reverse bias behavior.
  • Efficiency considerations: affected by diode voltage drops and power dissipation.
  • Ripple: residual AC variation present in rectified output.
  • Scalability: used in low-power signal circuits and high-power industrial systems.

Common types of Rectifier include half-wave rectifiers, full-wave rectifiers, and bridge rectifiers. Full-wave and bridge designs are preferred in most power supplies because they utilize both halves of the AC waveform and produce smoother DC output.

Workflow example: Full-wave bridge rectification:

ac_input = alternating_voltage()
positive_half = abs(ac_input)
dc_output = positive_half

Here, the rectifier inverts negative portions of the AC waveform so that current always flows in the same direction.

Conceptually, a Rectifier is like a traffic system that redirects cars so they all travel in the same direction, regardless of where they started.

See Diode, Power Supply, AC, DC, Voltage Regulator.