Electronics Basics L14: the Zener diode — a voltage that stays put
A Zener diode used backwards holds a fixed voltage (e.g. 5.1 V) across itself, with a resistor in series taking the rest — a simple voltage reference.
Need a voltage that stays put? Meet the Zener diode! 🔶⚡
➡️ A normal diode, turned around, blocks the current.
🔶 A Zener, turned around, opens at one exact voltage — this one at 5.1 V (like the 1N4733A).
📈 Push more volts in? It still holds about 5.1 V.
🤔 So where does the extra go? Into the resistor in front of it: 9 V − 5.1 V = 3.9 V across the resistor.
✅ 9 V in, 5.1 V out — a simple voltage reference. (The resistor is a must: it limits the current.)
Read the voiceover (transcript)
- Need a voltage that stays put? Meet the Zener!
- A normal diode, turned around, blocks the current.
- A Zener, turned around, opens at one exact voltage.
- Five point one volts. More in? Still five point one!
- So where does the extra go?
- Into the resistor in front!
- Nine in, five point one out!
- Next: the voltage regulator. Follow for Part fifteen!
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