​how to detect a dual base diode?

Last Update Time: 2018-10-26 17:10:47

how to detect a dual base diode?

discriminant base

discriminant emitter E.When the multimeter is placed in the RX1k2 block and the positive and reverse resistance values between any two electrodes are equal (2~10k2) with two forms,the two electrodes are B1 and B2,and the remaining one is the emitter E.

judge the base B and the base B2.The black pen is connected to E.and the two other electrodes are contacted with a red pen in order to measure two forward resistance values respectively. In manufacturing engineering, the second base B2 is near the PN junction, so the forward resistance between emitter E and B1 is small, and the difference between them is tens to tens of thousands of Europe. Therefore, when the resistance measured by the above method is relatively small, the electrode connected to the red pen is B2, and when the resistance is large, the electrode connected to the red pen is B.

Note: the above judgment base B1 and B2 methods are not suitable for all double base diodes. The positive resistance between E and B1 with individual pipes and the forward resistance between E and B2 are not significant. It is not very important to accurately determine which two bases of the double base diode are B and which is B2 in practice. Even if B1 and B2 are reversed, they will not damage the tube, only affect the pulse amplitude of the output. When the output pulse is small, the original identified Bi and B2 two electrodes can be adjusted to try to determine the correct connection of B1 and B2 with actual use effect.

whether the pipe is good or bad, the multimeter is placed in RX 1002 or RX1k gear. When the black pen is connected to the emitter E. red form to connect to B or B2, the positive resistance value of the double base diode PN junction should be a few to a few thousands of Europe, a little larger than the positive resistance value of the ordinary diode. The red pen is connected to the emitter E. and connected to the black pen with B or B2. At this time, the reverse resistance value of the double base diode PN junction is measured, and it should be infinite when normal. The red and black pens are respectively connected to B and B2, and the resistance value between the double base diode B1 and B2 should be within the range of 2~ 10k2. Too large or too small, it can not be used.

measure the negative resistance characteristic between B1 and B2, and connect 10V DC power supply. The multimeter is placed in the RX1002 or RX 1kQ block, the red pen is connected to the B1 pole, the black watch is connected to the E pole, which is equivalent to the 1.5V forward voltage between E- B. When normal, the multimeter pointer should be stopped at the infinite position, indicating that the pipe is in the cut-off state, because the pipe is at the peak point below P, and it is far from negative resistance zone, and IE is still a micro - an - level current. If the pointer deflects to the right, it shows that the tube has no negative resistance characteristic, which is equivalent to the volt ampere characteristic of an ordinary PN junction. Such pipes are not suitable for use.

the partial pressure ratio derived from the internal structure of the double base diode is expressed as the measured partial pressure ratio.

ETA =0.5+ (REB1 R EB) /2RBB.

When testing, use the RX 100 or RX 1kn barrier of multimeter to measure the Rem.Re of the double base diode.

And the RBB value can be used to calculate the partial pressure ratio.

In the form:

REBI is the forward resistance between E and B and two electrodes of double base diode, that is, black pen to E, red pen.

The resistance measured by B.

REB2 is the forward resistance value between E and B2 two electrodes of double base diode, that is, black pen to E, red watch.

The value of the B2 is measured by the pen.

RB is the resistance between the B of the double base diode and the B2 two electrode, that is, the multimeter red and the black pen respectively.

The resistance measured by arbitrary B1 and B2.