Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [zener]

Zener is an effect in semiconductors, the name of a diode that uses that effect and more generally any diode that has similar characteristics to a Zener diode.

Zener is an effect in semiconductors, the name of a diode that uses that effect and more generally any diode that has similar characteristics to a Zener diode.

Zener diodes have the unique characteristic of a reliable reverse bias breakdown voltage and are often used as simple voltage regulators or level shifters.

Zener breakdown is a distinct effect and in common usage is any diode that has a fixed reverse breakdown are called "Zeners" even if the mechanism is different.

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How to decide between a TVS or Zener diode for overvoltage protection?

I'll leave my specific circuit out of this for a more broad question: What criteria does one use when deciding whether to use a Zener diode or a transient voltage suppressor, for overvoltage protection on a particular application? Also when would…
JYelton
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Differences between TVS diode and Zener diodes, in diagrams and in practice?

I have been looking at circuit protection using TVS and Zener diodes. I have seen the following symbols used to represent TVS diodes in circuit diagrams: simulate this circuit – Schematic created using CircuitLab I guess the first question is…
feetwet
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Why do we connect a resistor before a Zener diode?

Why do we need a resistor in a Zener diode circuit, like in the diagram below? I understand it is to limit the current but how so, and why do we need it for a Zener diode? Does selecting different values of resistors affect the circuit performance?…
Sherby
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When/why would you use a Zener diode as a flywheel diode (on the coil of a relay)?

I have just been cogitating on the tutorial at http://www.electronics-tutorials.ws/io/io_5.html, and in the discussion of flywheel diodes it includes this sentence without further elaboration: As well as using flywheel Diodes for protection of…
Kaelin Colclasure
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Why is Zener avalanche noise saw tooth shaped?

I have the following schematic of a Zener based noise source:- simulate this circuit – Schematic created using CircuitLab When built, an oscilloscope reveals a saw tooth noise signal at the "Noise" node, like: The time base is 1us/div. Can anyone…
Paul Uszak
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Why is 5.1V the standard Zener voltage and not 5V?

Looking on Digikey there are ~1300 results for 5.1V Zener diodes compared to 6 for 5V ones. Is there any physics-related reason for this or is it something else?
Oelec
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Can a Zener diode that protects a switch against inductance when the switch opens, affect turn on speed of the valve when you close it again?

As you probably know, in the applications that the turn off speed of the solenoid valves are crucial, the simple flyback diode is not effective. Some people put a resistor in series with the flyback diode to alleviate the problem, but for real fast…
arudino.tyro
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How does a zener diode and a resistor regulate voltage?

I'm having trouble understanding the simple voltage regulator that can be built using a zener diode (from section 2.04 in the Art of Electronics). I know that it would be better to use amplifiers, et cetera, but I'm just trying to understand how…
Dr. Watson
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Why doesn't my multimeter show the correct Zener reverse voltage?

I have a 3.3V Zener diode, brand new from a reputable source. When I set my Fluke 101 multimeter to diode test mode, and put the black lead next to the dark bar on the diode and red on opposite side, the meter reads a voltage drop of about 0.689V.…
natevw
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What happens after a zener diode breaks down?

I've strapped a 6V zener diode across the 5V/GND rails of my circuit, and I want to know what will happen if my supply were to somehow fail pass 12V straight to the rest of my board. The zener will definitely fry, but what happens afterwards? Can I…
wjin
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Zener diodes in glass axial package - not inherently shielded from photoelectric effect?

I discovered today that a glass packaged axial leaded 5V Zener diode will become a source of about 0.450 Volts when the glass package is held in the beam of a low-power purple (405nm) laser pointer. The test setup: Scope probe (with ground clip)…
user98663
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Zener diode in series?

Is it OK to use a zener diode in series? Normally I see them across the output of a power source to limit the voltage to the value of the zener. Putting it in series instead should reduce the voltage by the value of the zener, yes? (so a 5V zener…
Majenko
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Is my Zener diode broken?

I test my Zener diode IV characteristic (reverse bias). It is a 1N4728 3.3V Zener diode, but its exponential IV curve seems like a normal diode with lower I_sat(?)
Willis Lin
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What is the point of the Zener diode in this schematic?

I looked at DALI application node and stumbled upon this circuit. Everything but the Zener diode D4 makes sense. What is the function of D4?
jonas
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Flyback diodes issues and pull-in & hold current issues in this Relay circuit

Although this may be a basic question but I'm still struggling with it. In this schematic, two zener diodes D1 and D2 are connected back-to back across relay coil L1. The BVds = -30V for Q1. Can I use 15V(Vz = 15V) zeners for D1 and D2 instead of…
jacks
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