How to lay a love for learning in puppies
WHY close mirrors in the house of the dead

As for the transistor to determine the emitter-base

As for the transistor to determine the emitter-base

If a bipolar transistor is erased markings determine where he had a conclusion can be their own.

For this purpose, a device for measuring resistance - ohm meter.

You will need

  • - A diode with a known tsokolevkoy-
  • - Ohmmeter.



Determine the polarity of the voltage on the probes of an ohmmeter. To do this, connect the diode with a known pinout first in one polarity and then in the other. When the probes are connected to the diode in the polarity at which the needle deviates to the cathode of the diode connected to the negative probe to the anode and - positive. Knowing the polarity of the voltage on the probe tips, you can start defining the transistor outputs.


Find out which of the terminals corresponds to the base. Connect an ohmmeter to the transistor three ways: between the emitter and the collector, between the emitter and base, between the collector and the base. Given that in all three cases it can be connected to one or the other polarity, all are six ways. The arrow will deviate when connecting one polarity only when the base terminal is involved. If the arrow does not deviate at any one of the polarity, then, both the output to which you connect the ohmmeter does not correspond to the base. A base - remaining.


Now it is possible to determine the structure of the transistor. Connect an ohmmeter in different polarities between the base terminal, the location of which you already know, and one of the remaining. If the needle is deflected when the base is attached to the plus in front of you NPN transistor structure. If a deviation occurs when the base is connected to the negative ohmmeter transistor structure - PNP.


It remains to determine where the emitter and the collector where. In the case of the NPN transistor structure, connect an ohmmeter between the two terminals, not the base. Connect the base with the advantage of an ohmmeter. Arrow rejected. Change the polarity of the ohmmeter to conclusions that are not basic. Reconnect base plus ohmmeter. The right is the way to turn, where the resistance was smaller. In this case, the emitter is connected to the negative terminal and the collector to positive. When checking the PNP transistor structure, proceed in the same way but connect the base in both cases net of an ohmmeter, and the emitter when properly turned on (when the resistance is less) corresponds to a plus of an ohmmeter, and the collector - a minus.

Comments are closed.