A diode is an electrical component that allows current to flow in one direction, while severely limiting current from flowing in the opposite direction. They change alternating current (AC) into pulsating direct current (DC), and are rated based on their type, voltage, and current capacity. A diode’s polarity is determined by a positive lead called an anode and negative lead, known as the cathode.
When a diode allows current flow, it is forward-biased. When it acts as an insulator and does not allow current to flow, it’s reverse-biased. When choosing the right type of diode for your application, consider voltage drop, maximum forward current, maximum reverse voltage, operating frequency, average rectified current, and tolerance as important factors.