Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [diodes]

Diodes are semiconductor components made from a P-type (or metal in Schottky diodes) and N-type material (usually silicon, but germanium, selenium, and gallium arsenide can also be used), that allow current to flow in one direction only.

There are many types of diodes:

  • Rectifying diode
  • Zener diode
  • Signal diode
  • Schottky diode
  • Avalanche diode
  • Photodiode
  • Light Emitting Diode (LED)
  • Laser diode
  • Tunnel diode
  • Varactor diode
  • Vacuum tube diode

Overview pages

Diodes overview, Diode types, applications

Type of diodes

Diodes overview, Diode types, applications (unattributed copying, but useful)

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What is "forward" and "reverse" voltage when working with diodes?

What is the difference between "forward" and "reverse" voltages when working with diodes and LEDs? I realize this question is answered elsewhere on the interwebs such as wikipedia, but I am looking for a short summary that is less of a technical…
JYelton
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How to choose a flyback diode for a relay?

A diode is put in parallel with a relay coil (with opposite polarity) to prevent damage to other components when the relay is turned off. Here's an example schematic I found online: I'm planning on using a relay with a coil voltage of 5V and…
Nate
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Why can't two series-connected diodes act as a BJT?

Another form of the question is: will joining two diodes with wires (pn-np) make a transistor-equivalent? I read that they are not equivalent, but why?
user23564
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Why do some diodes have a glass package?

Put simply, why do some diodes such as most Zeners and Schottky diodes have a glass package as opposed to the more traditional plastic package? Is it ease of manufacturing, thermal properties, or some other electrical phenomenon?
Hugoagogo
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How do I model an LED with SPICE?

What diode modifiers are used in practice to model LEDs with SPICE (Berkeley v.3f5)? These are available to me: # Name Parameter Units Default Example Area 1 IS Saturation current A …
tyblu
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Why isn't there a potential difference across a disconnected diode?

I know this question sounds silly, as if there was a potential difference a current would be created when the terminals are connected together and this would mean energy has come from somewhere. The reason I ask this though is that from my…
Blue7
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For a lower voltage drop one could use Schottky diodes, but what are the disadvantages of Schottky's?

In other words, why don't we always use Schottky diodes if they are so much better? What diode properties do Schottky diodes have that makes them unfit for certain applications?
jippie
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What is the reverse recovery time in a diode?

What is the reverse recovery time in a diode?
Cell-o
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Is paralleling diodes a bad idea?

I'm trying to repair an 800W power supply (see my previous question on this.) One thing that gets me is that the design has two schottky diode packages (in TO-220) in parallel. I was always told this was A Bad Idea, but since they are thermally…
Thomas O
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Purpose of the diode and capacitor in this motor circuit

I'm hooking up a small DC motor to an arduino using an NPN transistor using the following diagrams I found online: The circuit works, and I'm successfully able to make the motor run. Now, I'm seeking to understand why it works the way it does. …
Paul
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How does current get into a diode?

I think I understand more or less how an ordinary semiconductor diode works: Crystal doped differently in different regions, carrier depletion where they meet, bla bla bla. However, actual diodes that one builds circuits with do not end with bits of…
hmakholm left over Monica
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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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Common types of diodes to keep around

I'm working on stocking my home workshop with frequently used parts so I can spend more time tinkering and less time watching my mailbox. What are the differences between different kinds of diodes? I've seen schottky, zenner, signal, and rectifier…
Grant
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Lowest voltage drop diode possible

I am harvesting energy from an NFC device using a tuned antenna on my PCB. Through this method, I am able to generate about 3.05V. I would like to charge a super capacitor using the power harvested from the NFC device. To do this I have used the…
Anthony Phan
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Basic diode question about voltage-drop

We have been begun studying diodes in electronics 1 and I have really basic question that may be really dumb but I cannot find an answer online. If a diode is in series with a resistor and a voltage source that is set at the exact forward voltage…
ModularMan
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