Which one should I choose? Guides
Short comparisons to help you pick between parts that do similar jobs: a table, when to use which, common mistakes and a simulator you can try in your browser. All free.
MOSFET or BJT?
If you're switching loads above a few hundred milliamps, choose a MOSFET: it's voltage-driven and barely warms up when on. For small signals, LEDs, relay coils and cheap simple circuits, a BJT is still the most practical choice.
🔒 repair packZener or regular diode?
Use a regular diode to pass current one way, rectify AC or protect against reverse polarity. Use a zener to hold a fixed voltage or clamp an input against overvoltage; a zener is connected in reverse and always needs a series resistor.
🔒 repair packElectrolytic, ceramic or tantalum?
Use electrolytics for large, cheap storage, and ceramics for 100 nF decoupling next to supply pins and for high frequencies. Choose tantalum only when you need high capacitance in a small space, and leave twice the voltage margin.
🔒 repair packTriac or thyristor (SCR)?
Use a triac to control the power of a lamp, heater or brushed motor on mains AC; it conducts both ways. Use a thyristor where you need one-way control (controlled rectification, battery chargers, overvoltage protection).
🔒 repair packMOSFET or IGBT?
At low and medium voltages (roughly under 200 V) and high frequencies, the MOSFET is more efficient. 600 V and above, high current and low-to-medium frequency (welders, induction hobs, VFDs) is IGBT territory.
🔒 repair packCarbon film or metal film resistor?
Carbon film is fine for LEDs, pull-ups and general circuits. Use metal film for measurement, audio, op-amp feedback and precision dividers; the price gap is now so small that many designers use metal film everywhere.