Avometer detects the polarity of common diode and method of stand or fall

One. Avometer detects the polarity of common diode and stand or fall.
Detect principle: The one-way conductivity according to diode the diode with good performance of this one characteristic, its to resistor small, retrorse resistance is great; These two numerical value differ to had been jumped over greatly more. If the photograph is about the same the performance of demonstrative diode is bad or had damaged.
When measuring, choose avometer ” ohmic ” block. Block with R X100 or R Xlk commonly, and need not Rx1 or R X10k are blocked. The electric current that blocks because of Rxl is too big, easy burned-out diode, r Xlok blocks inside power source voltage is too big, easy puncture diode.
Measurement technique: two lists the club receives two electrode in diode to go up respectively, numerate metrical block value; Measure the trade that express a club again next, note block cost the 2nd times. If twice block value differs very big, explain this diode performance is good; Receive a standard according to measuring that watch bar with little resistance (say for to join) , judging an as marvellous as black list connective is the anode of diode, as marvellous as red watch connective is the negative pole of diode. Because of avometer inside of the anode of power source and avometer ” , ” insert Kong Liantong, inside of the negative pole of power source and avometer ” ＋ ” insert Kong Liantong.
If be measured twice block value is very little, show diode already puncture; If be measured twice block value is very great, explain diode interior has opened circuit: The block value that measures twice differs not quite, explain diode function owes beautiful. Below these circumstances, diode cannot be used.
Must point out: Because the volt-ampere of diode is characteristic dispute is linear, when the different resistor that uses avometer blocks the resistance that measures diode, can reach different resistance; When be being used actually, the electric current that has shed diode will be bigger, somes the resistance that consequently diode presents will be less.
2. Of special kind diode detect.
Diode of ① stabilized voltage. Stabilized voltage diode is a kind of job is in the retrorse puncture area, diode that has stable voltage effect. The measurement technique of the measurement of its polarity and function stand or fall and common diode is similar, different point depends on: Block when the Rxlk of use avometer when measuring diode, measure its are reversely resistor is very big, right now, change avometer Rx10k file, if appear avometer finger right deflexion is bigger angle, namely retrorse resistance reduces a lot of circumstances, criterion this diode is stabilized voltage diode; If retrorse resistor is basic changeless, showing this diode is common diode, is not stabilized voltage diode. The measurement of stabilized voltage diode the principle is: Avometer Rxlk blocks inside batteries voltage is lesser, won’t make normally common diode and puncture of stabilized voltage diode, measure the retrorse resistance that go out so very big. When when avometer changeover is blocked to Rx10k, voltage of the batteries inside avometer becomes very big, make stabilized voltage diode appears retrorse puncture phenomenon, its are so retrorse resistor drops a lot of, the diode of stabilized voltage of pressure ratio of retrorse puncture report as a result of common diode is gotten high much, consequently common diode not puncture, its are retrorse resistance is very great still.
LED(Light EMitting Diode) of ② glow diode. Glow diode is a kind of special diode that changes electric energy into light energy, it is a kind of new-style cold illuminant, commonly used at the n of electronic equipment directive, imitate shows wait for a circumstance. It often uses arsenic to change marry, phosphor is changed marry wait for compound semiconductor to be made. The glow color of glow diode basically depends on the data that uses semiconductor, can give out red, orange, yellow, green wait for 4 kinds of visible light. The crust of glow diode is transparent, the color of crust showed its glow color. Glow diode job is in to area, its guide is connected (open) working voltage prep above is common diode. Adscititious jumping over to voltage big, LED glow is brighter, but the attention answers in using, adscititious to voltage cannot shine diode exceeds his electric current of the biggest job, lest burn out pipe. To glow diode detect the Rx10k that the method basically uses avometer is blocked, its measurement technique and the judgement of stand or fall to its function and common diode are identical. But of glow diode to, retrorse resistor all is gotten greatly than common diode much. Measuring glow diode to resistor when, can see this diode has slightly glow phenomenon.
③ photoelectricity diode. Photoelectricity diode calls photosensitive diode again, it is a kind of special diode that is light energy changeover electric energy, there is a window that embedding glass on its envelope, accept the light in order to facilitate. Photoelectricity diode job is working reversely area. When having illumination, photoelectricity diode and common diode are same, retrorse electric current is very small (be less than O commonly. 1uA) , the retrorse resistance of photoelectric cell is very great () of above of a few Europe; When bright is illuminated, retrorse electric current increases apparently, retrorse resistor drops apparently (thousands of Europe goes to a few Europe) , namely retrorse electric current (call photocurrent) become direct ratio with illumination. Photoelectricity diode can be used at be being measured solely, can treat as a kind of the sources of energy (photocell) . It serves as sensor in applying extensively at photoelectricity to control a system. Of photoelectricity diode detect method and common diode are basic and identical. Different point is: Bright is illuminated and without illumination two kinds of circumstances fall, retrorse resistor differs very big: If measure a result to differ not quite, explain this photoelectricity diode already damaged or this diode is not glow diode.