Types of Diodes and When to Use Them

Ravikirana BRavikirana B
3 min read

A diode is like a one-way switch for current. But not all diodes do the same job. Letโ€™s look at the most commonly used types, explained in simple terms โ€” with real-world use cases.


1. ๐Ÿ”ฆ Standard Diode (Rectifier Diode)

๐Ÿง  Use: To allow current in one direction โ€” block reverse current.

  • โœ… Used in: Power supplies (AC to DC converters)

  • Example: 1N4007, 1N5408

๐Ÿ’ก When to use:
When you want to convert AC to DC or protect devices from reverse polarity.


2. ๐Ÿ’ก Light Emitting Diode (LED)

๐Ÿง  Use: Emits light when current flows through it.

  • โœ… Used in: Indicators, flashlights, displays, TV backlights

  • Example: Red, green, blue LEDs

๐Ÿ’ก When to use:
When you want to show status or light up something in a circuit.


3. ๐Ÿ›ก๏ธ Zener Diode

๐Ÿง  Use: Allows reverse current only after a certain voltage (Zener voltage).

  • โœ… Used in: Voltage regulation, protection

  • Example: 5.1V Zener, 12V Zener

๐Ÿ’ก When to use:
When you want to maintain fixed voltage or protect against voltage spikes.


4. ๐Ÿšช Schottky Diode

๐Ÿง  Use: Fast-switching diode with very low voltage drop

  • โœ… Used in: Fast circuits, solar panels, switching regulators

  • Example: 1N5819, SS14

๐Ÿ’ก When to use:
When you need high speed, less power loss, especially in DC-DC converters or solar.


5. ๐Ÿšฆ Photodiode

๐Ÿง  Use: Converts light into current

  • โœ… Used in: Remote controls, light sensors, alarms

  • Example: PIN photodiode

๐Ÿ’ก When to use:
When you want to detect light or sense IR signals.


6. ๐Ÿ’พ Varactor Diode (Varicap)

๐Ÿง  Use: Acts like a voltage-controlled capacitor

  • โœ… Used in: Radios, tuning circuits, RF systems

  • Example: BB204, MV2109

๐Ÿ’ก When to use:
When you need frequency tuning (like in FM radio or antenna matching).


7. ๐Ÿšจ Avalanche Diode

๐Ÿง  Use: Special diode that breaks down at a high voltage safely

  • โœ… Used in: Surge protection, voltage clamping

  • Example: 1N2970 series

๐Ÿ’ก When to use:
When you want to absorb high-voltage surges without damaging the system.


๐ŸŽฏ Summary Table

Diode TypeKey FeatureUse Case
RectifierOne-way currentAC to DC power supply
LEDEmits lightIndicators, lights
ZenerRegulates reverse voltageVoltage regulation, protection
SchottkyFast + low voltage dropHigh-speed switching, solar
PhotodiodeDetects lightIR sensors, light detectors
VaractorVoltage-controlled cap.Radio tuning, RF
AvalancheControlled breakdownSurge protection
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Written by

Ravikirana B
Ravikirana B

Iโ€™m 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, youโ€™ll find: ๐Ÿ”ง Electronics concepts explained with analogies (like water flow, gates, tanks) ๐Ÿ Python-based tech insights and automation ideas โšก Real tech reflections from both theory and hands-on work ๐ŸŒฟ 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 youโ€™re someone who loves understanding โ€œwhyโ€ and โ€œhowโ€, Tech Shodhaka is for you. Letโ€™s keep exploring, clearly and curiously. ๐Ÿ™Œ