The use skill of avometer

5V, it is the 9V of tall voltage or 15V together, its are black watch pen is to be being carried for pen of relatively red watch. Digital watch is commonly used the batteries of a 6V or 9V. In resistor archives, the electric current of the output that express a pen that pressing with a finger expresses wants for relative number watch a lot of bigger, with R × 1 Ω archives can make loudhailer gives out canorous " Da " sound, can illume even with archives of Ω of R × 10k glow diode (LED) . 3, in voltage archives, watch of pressing with a finger is compared for watch of word of logarithm of internal resistance photograph small, measure precision photograph to compare difference. The circumstance of small electric current of certain tall voltage cannot be measured even accurate, because its internal resistance is met,to be being measured circuit causes an effect (in the acceleration that measures television picture tube for instance the measured value when class voltage is met a lot of lower than real value) . The internal resistance of archives of digital watch voltage is very great, be in million Europe at least class, to be being measured circuit is affected very small. But the influence that extremely tall output impedance makes its get inductive tension easily, in interference of a few electromagnetism stronger circumstance measures the data that give may be empty. 4, anyhow, in opposite for the imitate circuit of tall voltage of big electric current is measured in applicable finger watch, for instance result of television, acoustics is put. In the digital circuit of low voltage small electric current in measuring, applicable number is expressed, for instance BP machine, mobile phone. Not be absolutely, can choose watch of pressing with a finger and digital watch according to the circumstance. 2, measure skill (if do not make a specification, show those who use is watch of pressing with a finger) : 1, measure mike of the horn, earphone, type that use a group: With R × 1 Ω archives, either expresses a pen to receive one aspect of the matter, point of another watch pen hits another end, normal when can give out ringing noise to measure " Da " sound. If do not ring, it is coil was broken, if small and noise is pointed, it is to have the problem that brush a circle, also cannot use. 2, measure capacitance: With resistor archives, choose proper span according to capacitance capacity, when noticing to measure to electroanalysising pen of capacitance black list should receive capacitance anode. ① , appraise measures the volume of capacity of capacitance of microwave law degree: Can reflect the standard electric capacity of same size by experience or ginseng, swing according to pressing with a finger most will decide substantially. The capacitance that consults need not compression value is same also, as long as the size is same can, for example the electric capacity that the capacitance that appraise measures F/250V of a 100 μ can use F/25V of a 100 μ will consult, want their finger to swing only most substantially same, can conclude the size is same. ② , appraise measures volume of capacity of capacitance of leather law degree: Want to use file of Ω of R × 10k, but the capacitance that can measure 1000pF above only. To 1000pF or a bit more largish capacitance, should express a needle to have a bit only swing, can think the capacity is enough. ③ , measure capacitance whether leakage of electricity: To the capacitance of above of 1000 small ways, can use R × first 10 Ω archives charges his quickly, preliminary estimate measures capacitance size, change archives of Ω of R × 1k to continue to be measured a little while next, at this moment pressing with a finger do not answer return, and should stop to be in or approach ∞ point very, have appearance of leakage of electricity namely otherwise. Time below to a few a few small ways or oscillation capacitance (for instance the oscillation capacitance of power source of color television switch) , characteristic to its leakage of electricity demand is very high, want to a bit leakage of electricity cannot be used only, can fill electric hind to convert again in archives of Ω of R × 1k at this moment archives of Ω of R × 10k continues to measure, same table needle should stop in ∞ to be in and do not answer return. 3, diode, dynatron, stabilized voltage measures to run stand or fall in the road: Because be in actual circuit, of dynatron slant the circumjacent resistance that buy resistor or diode, stabilized voltage provides is compared commonly big, be in mostly hundreds of thousands of ohmic above, such, 1 Ω archives comes to the 10 Ω of R × that we can use avometer or R × in the road measure the stand or fall that PN writtens guarantee. When the road is measured, with R × 10 Ω archives measures PN the knot is due more apparent positive and negative to character (if positive and negative differs to resistor not quite apparent, can convert 1 Ω archives comes to R × measure) , be in to resistor commonly needle of the watch when 10 Ω archives measures R × should be indicated control in 200 Ω , in R × needle of the watch when 1 Ω archives is measured should be indicated control in 30 Ω (come in and go out somewhat according to diverse list likelihood) . If measure a result to be worth too big or retrorse block to block,be worth too small, explain this PN knot has a problem, this pipe also has a problem. This kind of method to maintenance when particularly effective, OK and special apace finds out bad canal, can measure even piece have not completely broken but the pipe of characteristic addle. Be worth archives to measure knot of a certain PN to passing to resistor with small block when you for instance big, if you come down its solder to use archives of commonly used Ω of R × 1k to be measured again, may normal still, actually the character of this pipe already addle, cannot work normally or did not stabilize. 4, measure resistance: Important is to should choose good span, measure precision at full span of 1/3 ～ 2/3 when directive of pressing with a finger highest, reading is the most accurate. Those who want an attention is, when the large block that measuring million Europe level with archives of resistor of R × 10k is worth resistor, cannot hold finger in resistor two end, such human body resistor can make measure a result to slant small. 5, measure stabilized voltage diode: The stabilized voltage value that the stabilized voltage that we use normally provides is more than commonly 1.

5V, and the resistor archives under the R × 1k that pressing with a finger expresses is with 1 inside the watch.

Of 5V batteries power supply, such, with R × 1k the following resistor archives measures stabilized voltage to be in charge of as measuring diode same, have complete one-way conductivity. But the archives of R × 10k that pressing with a finger expresses is to use 9V or 15V batteries power supply, when measuring stabilized voltage to be worth the stabilized voltage that is less than 9V or 15V to be in charge of with R × 10k, retrorse block value won't be ∞ , have certain block value however, but this block is worth or want greatly prep above stabilized voltage is in charge of be worth to block. Such, we measure the stand or fall that gives stabilized voltage canal with respect to OK and preliminary estimate. But, good stabilized voltage canal has an exact stabilized voltage value even, how does appraise measure a value of this stabilized voltage below spare condition? Not difficult, it is OK to go looking for watch of a finger to come again. The method is: Express archives of 10k of park R × first, its are black, red watch pen receives the cathode that is in charge of in stabilized voltage and positive pole respectively, give the real work state that stabilized voltage runs with respect to imitate at this moment, reassume expresses 10V of × of V of park voltage archives or V × 50V additionally together (be worth according to stabilized voltage) on, red, black list the pen is joined respectively receive a moment ago that is expressed on pen of black, red watch, measuring the voltage that go out to be worth at this moment basically is the stabilized voltage value that this stabilized voltage provides. Say " basically " , because the first expresses what be in charge of to stabilized voltage to slant,be when buy electric current is used normally relatively slant somes buy electric current is a bit small, measure the stabilized voltage value that give to be able to slant a bit so a bit bigger, but differ basically not quite. This method but the stabilized voltage canal that appraise measures stabilized voltage value to be less than pressing with a finger to express high-pressured batteries voltage. If the stabilized voltage cost of stabilized voltage canal is too high, can be measured only with the method of extra power supply (such looking, we are in when choosing pressing with a finger to express, those who choose what high-pressured batteries voltage is 15V to want to compare 9V is some more applicable) . 6, measure dynatron: Normally we should use file of Ω of R × 1k, no matter be NPN canal or PNP canal, no matter be small-power, medium,power, high-power is in charge of, measure its Be to written guarantee Cb knot should present as identical as diode one-way conductivity, retrorse resistor infinity, its are being controlled in 10K about to resistor. Measure the stand or fall of pipe character for farther appraise, return meet an emergency to change resistor file when necessary undertake for many times metrical, the method is: 10 Ω archives measures buy R × PN writtens guarantee guide electrify block is controlled in about 200 Ω ; 1 Ω archives measures buy R × PN writtens guarantee guide electrify block is controlled in about 30 Ω , (above is 47 model the watch is measured data, other model watch differs somewhat probably, can try more measure a few good canals to be summed up, accomplish know fairly well) if reading slants big too much, can conclude the character of pipe is bad. Still can measure Ω of 10k of × of watch park R again, the pipe with again low compression (basically the compression of dynatron is in 30V above) , its Cb writtens guarantee retrorse resistor also should be in ∞ , but the retrorse resistor that its Be writtens guarantee may have some, the meeting that express a needle has deflexion a bit (the 1/3 that won't exceed full span commonly, differ according to the compression of pipe and differ) . Same, measuring Ec with archives of Ω of R × 10k (be in charge of to NPN) or between Ce (be in charge of to PNP) when resistor, the likelihood that express a needle somewhat deflexion, but this does not state pipe is bad. But when using the following archives of Ω of R × 1k to measure the resistance between Ce or Ec, the directive that express a head should be infinity, otherwise pipe has a problem namely. Should explain of a bit is, above measures be in the light of silicon canal character, not applicable to germanium canal. Nevertheless germanium canal also saw rarely now. Additional, what say " retrorse " it is in the light of PN knot character, to NPN canal and PNP canal direction are different actually. For the most part model seals common now dynatron, how do 3 of accurate judgement dynatron cite a base which be B, C, E? The B of dynatron extremely measure very easily come out, but how to conclude which be C which be E? Here recommends 3 kinds of methods: The first kind of method: To having the list of pressing with a finger that measures dynatron HFE to insert aperture, after measuring a B pole first, insert dynatron in inserting aperture to go at will (of course B is to be able to be inserted extremely accurate) , measure HFE value, come over pipe to be measured again again next, when measure HFE value is more greatly, the position that each pin inserts is correct. The 2nd kind of method: Measure the watch that inserts aperture to having HFE, or too big inconvenience inserts tube insert aperture, can use this kind of method: To NPN canal, measure a B pole first (pipe is NPN or PNP and its B foot are measured very easily piece, yes? ) , archives of Ω of 1k of × of watch park R, the E that receives red watch pen hypothesis extremely (the hand that notices to take red watch pen does not come up against watch nib or pin) , the C that black list pen receives hypothesis extremely, hold watch nib and this pin with finger at the same time, take pipe, the tip of the tongue that uses you licks B pole, see the deflexion with the due and regular guide that express a head, if you express a pen to be received correctly each, somes deflexion of pressing with a finger will be big, if be received incorrectly, somes deflexion of pressing with a finger will be small, the difference is apparent. Can decide from this the C of pipe, E pole. To PNP canal, the E that should receive black list pen hypothesis extremely (the hand does not come up against nib or pin) , the C that red watch pen receives hypothesis extremely, hold watch nib and this pin with finger at the same time, lick B pole with the tip of the tongue next, if each express a pen to be received correctly, meeting deflexion must compare the index that express a head big. Pen of the watch when be being measured of course wants exchange to be measured twice, compare the ability after reading to decide finally. This method applies to the dynatron of all appearances, convenient and practical. The basis expresses the deflexion range of the needle, still can estimate the enlarge ability that gives pipe, of course this is by experience. The 3rd kind of method: Decide first the NPN of pipe or PNP type reach his after B pole, archives of Ω of 10k of × of watch park R, to NPN canal, black list pen receives E pole, when red watch pen receives C pole, watch needle may have certain deflexion, to PNP canal, black list pen receives C pole, when red watch pen receives E pole, watch needle may have certain deflexion, won't have deflexion conversely. Also can decide from this the C of dynatron, E pole. Do not cross the pipe to tall compression, this method is not applicable. Seal a canal to the common high-power model that imports model, its C is extremely basic it is an inter (I had not seen B inter) . B of some of medium, small-power canal is extremely likely inter. The other model dynatron of the 9014 dynatron that use than as usual and its series, dynatron such as 2SC1815, 2N5401, 2N5551, its B extremely some is in among. Of course they also have C pole inter. Change in maintenance so when dynatron, especially these small-power dynatron, cannot take press unvarnished and direct how to go up, must measure first. CNC Milling