Kuidas mõõta a triood kasutamine a multimeeter
(1), kolm inversioonid, find the base
To test the triode, use the ohm gear of the multimeter, and select the R×100 or R×1k gear. For pointer multimeters, the red test lead is connected to the negative electrode of the battery in the meter, and the black test lead is connected to the positive electrode of the battery in the meter. Suppose we don't know whether the triode under test is NPN type or PNP type, and we can't tell what electrode each pin is. The first step in the test is to determine which pin is the base. At this time, we randomly take two electrodes (for example, these two electrodes are 1 and 2), use the two test leads of the multimeter to measure its forward and reverse resistance upside down, and observe the deflection angle of the needle; then, take 1 , 3 two electrodes and 2, 3 two electrodes, respectively measure their forward and reverse resistance upside down, and observe the deflection angle of the hands. Among these three upside-down measurements, there must be two measurement results that are similar: that is, in the upside-down measurement, the deflection of the hands is large at one time, and the deflection is small at the other time; The pin is the base we're looking for. the
(2), PN junction, fixed tube type
(3), mööda nool, the läbipaine on suur
1) For the NPN triode, based on the principle of the flow direction of the NPN triode penetration current, use the black and red test leads of the multimeter to measure the forward and reverse resistances Rce and Rec between the two poles upside down, kuigi the pointer of the multimeter deflects while the two measurements The angles are very small, but if you observe hoolikalt, there will always be a veidi suurem läbipainde nurk. At see aeg, vool suund of the current must be: must test plii→c pole→b pole→e pole→red test plii, ja the current flow direction is exactly the same as the arrow in the triode symbol. The direction is the same, so at time, the black test lead must olema ühendatud to the Kollektor C, ja THE RED TEST LEAD MUST BE CONNECTED TO The Emitter E.
2) For the PNP type triode, the reason is also similar to the NPN type. The current flow direction must be: black test lead→e pole→b pole→c pole→red test lead, and the current flow direction is ka consistent with the direction of the arrow in the triode symbol, so At this time, the black test lead must be connected To The Emitter E, And The Red Test Lead Must Be Connected To The Collector C.
(4) Unable to detect, move your mouth
If ajal the measurement process of "following the arrow, the deflection is large", if the deflection of the two measurement osutid before and after the upside down is too small to be distinguished, it is necessary to "move your mouth". The specific method is: in the two measurements of "following the arrow, the deflection is large", use two hands to pinch the junction of the two test leads and the pins, hold the base electrode b with your mouth (or use your language to hold it) The collector c and the emitter e can be distinguished by the judgment method of "following the arrow, large deflection". Among ong them% 2c the human body plays the role of DC bias resistor, the purpose is to make the effect more obvious.
