Testing different transistors : rules and recommendations

How ping transistor: setting the meter

Each meter, which has a special mode shown in the diode device icon.Conclusions multimeter should be connected in the same connection in resistance mode: black wire - to the COM port, and red - to the output impedance measurement, frequency and voltage.The legacy analog devices can not be this mode, so you need to install on the device resistance measurement mode and set the highest limit of the measuring switch.

How to check bipolar transistor?

bipolar transistor is an alternation of semiconductor.Differ pnp and npn-type.Verification is similar to check diodes.

Check the accuracy by following this advice:

1. To properly connect the meter leads to the conclusions of the transistor, it is necessary to determine the location base, collector and emitter.To determine the base connect black test expectation first base electrode and a second (red) - first, second, then the third.Swap probes need until the meter does not show a certain voltage drop.Then, it may be noted that this couple - the "base-collector" or "the base-emitter".Finding the emitter and collector can be determined using a digital multimeter.In most cases, resistance and voltage drops a little more at the emitter junction.
2. is necessary to put the meter in the usual resistance measurement mode.The approximate limit of the measurement, which must be put -2000.
3. multimeter is connected to each pair of contacts in two ways.Conducted measurements and compares the results.
4. bipolar transistor can be considered a workable, if during measurement of the same polarity on the multimeter shows the existence of a finite resistance, and at the back - shows the unit.Desoldering part of the board is not necessary.

How to test igbt transistor?

Check transistors with insulated gate is not recommended to do on their own, as manufacturers of such products, as a rule, they are tested.A separate check should be done very carefully to avoid damaging the radio components.

When testing is necessary to adhere to these rules:

1. Multimeter to work in diode test mode.
2. Remove conductive material and close the base to the emitter is possible only when the item is out of the circuit.
3. must connect the SP to the gate and the collector, and then to the gate and the emitter and measure the resistance.If the working unit, the measured resistance is equal to infinity.

How to check the FET?

FETs are more sensitive than bipolar, because they are managed by means of the field, which voltage is applied to the gate.Checking FET multimeter greatly differs from the previous one.A necessary condition for defining the serviceability of the field effect transistor is between the three terminals of the device is displayed on the screen of the meter infinite resistance.

To understand how to ring a field effect transistor, it is necessary to pay attention to some nuances.Verification has two subtleties:

1. The power transistors in the circuit between the drain and source has a diode.
2. Touching the gate is positive or negative terminal, the gate opens and the channel resistance decreases.

During testing of the FET, the device feet should be short-circuited.