Testing diodes is not quite the same as testing a resistor since you need an expertise to do it. In the event that you don't have a clue or wrongly test a diode you will be not able to fix the hardware. A terrible diode you think it is acceptable. This will burn through your valuable time.
A rectifier diode can bomb in one of the four different ways. It can turn into:
- Open
- Shorted
- Leaky
- Breakdown when in full working voltage
A simple multimeter or advanced multimeter can be utilized to check
for all the initial three conditions with the exception of the last one where the
diode breakdown in full working voltage. From my of experienced
in the electronic fixing line, I found that checking diode utilizing simple
multimeter is more exact than utilizing a computerized multimeter. I could clarify
to you why I favored simple meter. I don't think about you since I truly
went over a lot of diodes where it checked OK utilizing computerized multimeter
be that as it may, bombed when test with simple meter.
The initial step on the most proficient method to test a diode is to expel one of the diode lead. You can't
continuously be sure if a diode is positive or negative in the event that you act in-circuit test, in light of the fact that
of back circuits through different parts. To be certain beyond a shadow of a doubt, you should
lift, or detach, one diode lead from the circuit to maintain a strategic distance from back circuits.
Except if you are exceptionally secure with the board you are checking. Some of the time I do discovered awful
diodes while checking it ready. Your accomplished will reveal to you when to check a diode
ready or off-board. On the off chance that you are new to electronic fix, I strongly suggest that
you check a diode with a lead expelled from the board.
I will set my simple meter to x1 ohms to check for current diode spillage invert and
forward testing. Interfacing the dark test of your meter to the cathode and red test
to the anode, the diode is converse one-sided and should resemble an open perusing. Associating
the red test of your meter to the cathode and dark test to the anode, the diode is forward one-sided and the meter should peruse some estimation of opposition. On the off chance that you have two readings, at that point most likely the diode is shorted or flawed and you ought to supplant it. In the event that you don't get any perusing either forward or invert inclination, the diode is viewed as open.
The genuine issue while checking a diode utilizing the diode test capacity of an advanced meter is that an open or flawed diode, the meter now and again peruses ok(0.6). This is because of advanced meter diode test yield voltage (which you can gauge the yield test utilizing another meter) is around 500mv to 2v. A simple meter set to x1 ohms have yield about 3V(remember the two 1.5V battery you introduced in the meter!). The 3V voltage is sufficient to show you the precise perusing of a diode when under test.
Regardless of whether you have a decent perusing at x1 ohms doesn't imply that the diode is acceptable . You
presently need to set your meter to x10K to test the diode once more. The yield voltage of
x10k ohms is about 12V(remember the 9v battery in your meter-1.5v+1.5v+9v=12v). Once more
the diode under test should show just one perusing. This is special case to Schottky diode
where it have two readings however not shorted perusing. In the event that the meter gave one perusing, at that point
the diode under test is acceptable. In the event that it has two readings, at that point most presumably the diode is either
shorted or broken. The advanced meter can't test it on the grounds that the yield from the meter is as it were
500mv to 2V.
On the off chance that a diode breakdown when under full working voltage, it is highly unlikely to testing diode (except if you have an over the top expensive diode checker which extraordinarily intended to find this sort of problem).Substituting with a realized decent diode is regularly the best way to demonstrate that a discontinuous diode is causing a specific issue. Once in a while an irregular diode could be find utilizing a coolant shower.
Alert: Be sure that force is expelled from any circuit before playing out any of the accompanying diode checks, in any case meter or circuit harm could result.
End In request to accurately test diode work you have to set the simple meter
to x1 ohms and x10K ohms run.
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