I bought a package of 45v 15a Schottky Diodes. When I test them using the diode selection on a meter, they show to be working. However, when I test them by applying a reverse voltage to them, they pass that voltage through. They are not blocking reverse voltage. Is this a characteristic of Schottky diodes, where they might block current and not voltage? Is there a trick to using Schottky Diodes? As a blocking diode, they don't seem to work right.
Usually, standard low voltage silicon diodes have a leakage voltage of around .06 -.2v. Higher voltage silicon diodes (like 600V) have much higher leakage voltages, so I don't buy them for wind and solar applications. These Schottky diodes leak almost full voltage applied.
I did test the Schottky Diode with a 12v LED string. When blocking, is did pass full battery voltage, but the current was so little, the LED's barely lit. Schottky seems to be blocking current, not voltage.
Since I have an amp meter, I did two test.
Test A: Using the LED string, for the Schottky forward biased, it used .03a, and when the Schottky is blocking, my meter didn't register any current. A little current did pass to produce very dim light, but now enough to register on my amp meter.
Test B: I did a second test using a 20 OHM resistor load. For the Schottky forward biased, the current used was .59a. When the Schottky is blocking, my amp meter didn't register any current.
These test seem to verify the current blocking aspect of Schottky, but not any voltage blocking. These restrictions limit how I can use Schottky diodes. They are not drop in replacements for Silicon Diodes in circuits.
