What is created when a diode is used in a circuit?

When a diode is used in a circuit, it primarily allows current to flow in one direction while blocking it in the opposite direction. This property of diodes is instrumental in converting alternating current (AC) into direct current (DC).

In an AC circuit, the current changes direction periodically, which means both positive and negative voltages are present. When a diode is incorporated into such a circuit, it will only permit the positive portion of the AC waveform to pass through. As a result, the output from the diode will be a unidirectional flow of current, effectively creating DC current from the originally alternating AC source.

This characteristic is fundamental in various applications, such as power supplies, where AC from the mains voltage is converted to DC for use in electronic devices.