The Diode, are they mostly use for safety nets?

Discussion in 'General Electronics Chat' started by RyanD, Jan 19, 2010.

  1. RyanD

    Thread Starter Member

    Jan 14, 2010
    30
    0
    Most of the circuits I've been studying to learn from have diodes for two reasons. The first(most common) is to make sure current doesn't flow the wrong way and break something. The second is to drop the voltage a little(why not just use a resistor?) So, are these the main reasons to use one, are diodes necessary or just a safety precaution?
     
  2. VoodooMojo

    Active Member

    Nov 28, 2009
    503
    53
    also used for polarity protection and coil suppression.

    see attached for considerations of using diode as coil suppression.
    a resistor can work as well.
     
  3. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,692
    901
    The voltage drop across a resistor is directly proportional to the current. The drop across a diode is not and is much less affected by the current. See this graph from the 1N4148 datasheet:

    [​IMG]

    John
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,172
    397
    Most usage is for one way current control, power rectfication, reverse polarity protection, implementing diode OR gates & other uses that I can not think of.
     
  5. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Not just OR gates, they also make AND gates.

    I regularly use diodes as voltage references, similar to zeners. They are relatively stable, other than temperature. They are predictable enough to be used as temperature sensors.
     
Loading...