Types of Diodes and When to Use Them

A diode is like a one-way switch for current. But not all diodes do the same job. Letโs look at the most commonly used types, explained in simple terms โ with real-world use cases.
1. ๐ฆ Standard Diode (Rectifier Diode)
๐ง Use: To allow current in one direction โ block reverse current.
โ Used in: Power supplies (AC to DC converters)
Example: 1N4007, 1N5408
๐ก When to use:
When you want to convert AC to DC or protect devices from reverse polarity.
2. ๐ก Light Emitting Diode (LED)
๐ง Use: Emits light when current flows through it.
โ Used in: Indicators, flashlights, displays, TV backlights
Example: Red, green, blue LEDs
๐ก When to use:
When you want to show status or light up something in a circuit.
3. ๐ก๏ธ Zener Diode
๐ง Use: Allows reverse current only after a certain voltage (Zener voltage).
โ Used in: Voltage regulation, protection
Example: 5.1V Zener, 12V Zener
๐ก When to use:
When you want to maintain fixed voltage or protect against voltage spikes.
4. ๐ช Schottky Diode
๐ง Use: Fast-switching diode with very low voltage drop
โ Used in: Fast circuits, solar panels, switching regulators
Example: 1N5819, SS14
๐ก When to use:
When you need high speed, less power loss, especially in DC-DC converters or solar.
5. ๐ฆ Photodiode
๐ง Use: Converts light into current
โ Used in: Remote controls, light sensors, alarms
Example: PIN photodiode
๐ก When to use:
When you want to detect light or sense IR signals.
6. ๐พ Varactor Diode (Varicap)
๐ง Use: Acts like a voltage-controlled capacitor
โ Used in: Radios, tuning circuits, RF systems
Example: BB204, MV2109
๐ก When to use:
When you need frequency tuning (like in FM radio or antenna matching).
7. ๐จ Avalanche Diode
๐ง Use: Special diode that breaks down at a high voltage safely
โ Used in: Surge protection, voltage clamping
Example: 1N2970 series
๐ก When to use:
When you want to absorb high-voltage surges without damaging the system.
๐ฏ Summary Table
Diode Type | Key Feature | Use Case |
Rectifier | One-way current | AC to DC power supply |
LED | Emits light | Indicators, lights |
Zener | Regulates reverse voltage | Voltage regulation, protection |
Schottky | Fast + low voltage drop | High-speed switching, solar |
Photodiode | Detects light | IR sensors, light detectors |
Varactor | Voltage-controlled cap. | Radio tuning, RF |
Avalanche | Controlled breakdown | Surge protection |
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Written by

Ravikirana B
Ravikirana B
Iโm Ravikirana B โ an engineer driven by curiosity and clarity. I specialize in electronics, Python programming, and work across a range of technologies to build real-world solutions that blend hardware and software. I started Tech Shodhaka to share what I learn, simplify what I know, and spark curiosity in those who want to understand how tech actually works โ especially in our own languages and ways of thinking. Here, youโll find: ๐ง Electronics concepts explained with analogies (like water flow, gates, tanks) ๐ Python-based tech insights and automation ideas โก Real tech reflections from both theory and hands-on work ๐ฟ A touch of Kannada-English expression for wider reach I believe in making learning accessible, especially for students and self-learners from smaller towns like mine. If youโre someone who loves understanding โwhyโ and โhowโ, Tech Shodhaka is for you. Letโs keep exploring, clearly and curiously. ๐