haaphiladelphia.blogg.se - How to test a 2n3055 transistor with a multimeter

My favorite tool for junctions was a VTVM. In other hand, if the meter reads a very low resistance in both directions, then the diode is said to be shorted.The battery was applied through a *resistor*.

If the meter indicates a very high resistance or OL in both forward and reverse-biased conditions, then the diode is said to be opened. Since in reverse biased condition diode offers a very high resistance.įrom the above it is clear that for proper working of the diode, DMM should read a very low resistance in the forward-biased condition and a very high resistance or OL in reverse-biased condition.

If the meter shows a very high resistance value or OL on meter display, then the diode is good and functions properly.

Keep the selector in high resistance mode (may be 100K ohm) for the reverse bias testing procedure.

Now reverse the terminals of the multimeter such that anode is connected to black probe and cathode to red probe.

If the meter displays a moderately low value on the meter display, which may be a few tens to few hundred ohms, then the diode is good and healthy.

When the diode is forward-biased, the resistance of the diode is so small.

Connect the red probe to the anode and black probe to the cathode.

Keep the selector in low resistance (may be 1K ohm) mode for forward-bias.

Keep the digital multimeter (DMM) in resistance or ohmmeter mode by rotating the central knob or selector to the place where ohm symbol or resistor values are indicated.

Identify the terminals anode and cathode of the diode.

Ohmmeter Mode Testing Step by Step Instructions: Therefore, the multimeter will indicate zero voltage value, but in some cases it will display a very little voltage as the voltage drop across the diode. Shorted diode means diode behaves as a closed switch so the current flows through it and the voltage drop across the diode will be zero. Therefore, the meter will indicate OL in both reverse and forward-biased conditions. Open diode means diode behaves as an open switch in both reverse and forward-biased conditions. The diode defect can be either open or short.

If the meter shows irrelevant values to the above two conditions, then the diode is defective.

Hence the meter should read OL (which is equivalent to open circuit) if the diode is healthy. This is the reverse biased condition of the diode where no current flows through it.

Now reverse the terminals of the meter that means connect the red probe to cathode and black to anode.

For germanium diodes this value is in between 0.25 to 0.3. If the displayed voltage value is in between 0.6 to 0.7 (since it is silicon diode) then the diode is healthy and perfect.

Observe the reading on the meter display.In this mode multimeter is capable to supply a current of 2mA approximately between the test leads. Keep the digital multimeter (DMM) in diode checking mode by rotating the central knob to the place where the diode symbol is indicated.Identify the diode terminals (anode and cathode).Diode Mode Testing Step by Step Instructions: The diode testing using a digital multimeter (DMM) can be carried in two ways as there are two modes available in DMM to check the diodes such as diode mode and ohmmeter mode. Testing of a Diode using Digital Multimeter If the meter fails to show above readings, then the diode is said to be defective or bad.If the meter indicates OL or a very high resistance, then it refers to the perfect condition of the diode.In this case, the diode is said to be in reverse bias. Now put the selector in high resistance position and reverse the terminals of the meter by connecting positive terminal to the cathode and negative terminal to anode.If the meter indicates a low resistance value, then it says that the diode is healthy.Connect the positive terminal of the diode to the positive terminal of the multimeter.Connect the negative terminal of the diode to the negative terminal of the multimeter.Set the multimeter selector switch in low resistance value.Testing of a Diode using Analog Multimeter Step by Step Instructions: The method of testing a diode with an analog meter is quite straightforward. Just two tests are needed with the multimeter to ensure that the diode works satisfactorily.

The basic diode test is very simple to perform.