Diodes are semiconductor devices that allow current to flow in one direction only, and they come in various types depending on their application. Here are two common types:
1. **Rectifier Diodes:**
- **Purpose:** These diodes are primarily used for converting alternating current (AC) to direct current (DC). They are commonly found in power supply circuits.
- **Characteristics:** Rectifier diodes can handle high current and voltage levels. They are designed to withstand the stresses of high-power operation. A typical example is the 1N4007 diode, which can handle up to 1000V and 1A.
- **Operation:** When AC voltage is applied, the rectifier diode conducts during the positive half-cycle and blocks current during the negative half-cycle, thus allowing only DC to pass through.
2. **Zener Diodes:**
- **Purpose:** Zener diodes are used primarily for voltage regulation. They are designed to maintain a constant output voltage regardless of changes in the input voltage or load conditions.
- **Characteristics:** These diodes have a well-defined breakdown voltage known as the Zener voltage. When the reverse voltage applied to the Zener diode exceeds this voltage, the diode conducts in reverse, stabilizing the voltage across it.
- **Operation:** In a circuit, the Zener diode is often used in a reverse-biased configuration. When the reverse voltage reaches the Zener breakdown voltage, the diode starts conducting in the reverse direction, maintaining a stable voltage across it.
Both types of diodes serve crucial roles in electronic circuits, with rectifier diodes ensuring proper power conversion and Zener diodes providing voltage stability.