Doing experiment on Schottky diode

Discussion in 'General Electronics Chat' started by mrel, Oct 27, 2014.

  1. mrel

    Thread Starter Active Member

    Jan 20, 2009
    97
    1
    Hello people
    Looking for anwers on a schottky diode.
    Connect 6 volts gel battery using Schottky Diode experiment with following schottky diode( 1n5822,1N5817) .
    First experiment was connect cathode side of diode to postive side of the battery got reading around 6 volt.
    Second experiment was to connect the anode side of the diode to postive side of the 6 volt battery also got reading around 6 volts.
    Should diode block voltage on one side (should be zero reading on one side of diode connection).
    mrel
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,534
    Did you have a resistor or a light bulb anywhere? It sounds like you popped the diode.
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,764
    2,534
    Schottky's act just like regular diodes, but they are very fast (good for RF), They also drop around 0.2-0.3, similar to a germanium diode. But any diode needs current limiting if you connect it to a battery.

    This makes them ideal for crystal radios. Indeed, the crystal in an old fashioned crystal radio was a naturally occurring Schottky diode.
     
  4. MrAl

    Well-Known Member

    Jun 17, 2014
    2,418
    488
    Hello there,


    Schottky diodes have more than usual reverse leakage so you may be seeing the same voltage because the diode is not a perfect blocker in reverse. It's like connecting a 10k resistor to a battery and then measuring the voltage without any load. If the internal resistance of the meter is high (like 1 to 10 megohms) then it will look like the diode is shorted when it's just the leakage.

    This of course means you need a load when you measure the voltage, a load like even 100k would show better results, but 10k even better. Measure the voltage across the load and see how much difference it makes.

    To compare, try the same test with a 1N4148 diode which is a 'regular' si diode.
     
  5. mrel

    Thread Starter Active Member

    Jan 20, 2009
    97
    1
    Would these two schottky diode (1n5822,1h5817) be good to use as bypass diode and blocking diode for 10watts and 12 volts rate solar panel?
     
  6. ian field

    Distinguished Member

    Oct 27, 2012
    4,413
    782
    A bit of leakage is normal for a Shottky-barrier diode - if your voltmeter has high enough resistance, there won't be a lot of volt drop with the diode either way round.

    Make a potential divider with the diode and a 220R resistor to put across the battery for measuring the volt-drops.
     
Loading...