19-03-2014  (1801 lectures) Categoria: ESR

ESR meter

http://www.mikrocontroller.net/svnbrowser/transistortester/

Valores de ESR típicos para condensadores (por uF / V)

Capacidad 10V 16V 25V 35V 63V 160V 250V
1uF - - 5 4 6 10 20
2.2uF - - 2.5 3 4 9 14
4.7uF - - 6 3 2 6 5
10 uF - 1.6 1.5 1.7 2 3 6
22 uF 3 0.8 2 1 0.8 1.6 3
47 uF 1 2 1 1 0.6 1 2
100 uF 0.6 0.9 0.5 0.5 0.3 0.5 1
220 uF 0.3 0.4 0.4 0.2 0.15 0.25 0.5
470 uf 0.15 0.2 0.25 0.1 0.1 0.2 0.3
1000 uF 0.1 0.1 0.1 0.04 0.04 0.15 -
4700 uF 0.06 0.05 0.05 0.05 0.05 - -
10000 uF 0.04 0.03 0.03 0.03 - - -


An ESR meter (equivalent series resistence) is a two-terminal electronic measuring instrument designed and used primarily to measure the equivalent series resistance (ESR) of real capacitors; usually without the need to disconnect the capacitor from the circuit it is connected to. Most ESR meters work by applying voltage pulses to the capacitor under test which are too short to appreciably charge it; any voltage appearing across the capacitor is due to ohmic drop across the ESR. Measuring ESR can also be done by applying an alternating voltage at a frequency at which the capacitor's reactance is negligible, in a voltage divider configuration.

Other types of meter, including normal capacitance meters, cannot be used to measure a capacitor's ESR, although a few combined meters are available which measure both ESR and out-of-circuit capacitance. A standard (DC) milliohmmeter cannot be used to measure ESR, because a steady direct current cannot be passed through the capacitor.

Most ESR meters can also be used to measure non-inductive low-value resistances, whether or not associated with a capacitor; this leads to a number of additional applications described below.

Need for ESR measurement

Aluminium electrolytic capacitors have a relatively high ESR that increases with age, heat, and ripple current; this can cause the equipment using them to malfunction. In older equipment, this tended to cause hum and degraded operation; modern equipment, in particular switch-mode power supplies, is very sensitive to ESR, and a capacitor with high ESR can cause equipment to malfunction or cause permanent damage requiring repair, typically by causing power supply voltages to become excessively high.[1] This type of capacitor is very often used because it is inexpensive and has a very high capacitance per unit volume or weight; typically, these capacitors have capacitance from about one microfarad to tens of thousands of microfarads.

Capacitors with faults leading to high ESR often bulge and leak, making them easy to identify visually; however, capacitors that appear visually perfect may still have high ESR, detectable only by measurement.

Precise measurement of ESR is rarely necessary, and any usable meter is adequate for troubleshooting. Where precision is required, measurements must be taken under appropriately specified conditions, because ESR varies with frequency, applied voltage, and temperature. A general-purpose ESR meter operating with a fixed waveform is unlikely to be suitable for precise laboratory measurements.

Principles of operation

Most ESR meters work by discharging a real electrolytic capacitor (essentially equivalent to a perfect capacitor in series with an unwanted resistance, the ESR) and passing an electric current through it for a short time, too short for it to charge appreciably. This will produce a voltage across the device equal to the product of the current and the ESR plus a negligible contribution from a small charge in the capacitor; this voltage is measured and its value divided by the current (i.e., the ESR) shown in ohms or milliohms on a digital display or by the position of a pointer on a scale. The process is repeated tens or hundreds of thousands of times a second.

Alternatively an alternating current at a frequency high enough that the capacitor's reactance is much less than the ESR can be used. Circuit parameters are usually chosen to give meaningful results for capacitance from about one microfarad up, a range that covers typical aluminium capacitors whose ESR tends to become unacceptably high.

The ESR considered acceptable depends upon capacitance (larger capacitors usually have lower ESR), and may be read from a table of "typical" values, or compared with a new component. In principle, the manufacturer's upper limit specification for ESR can be looked up in a datasheet, but this is usually unnecessary. When a capacitor whose ESR is critical degrades, power dissipation through the higher ESR usually causes a rapid and large runaway increase, so go/no-go measurement is usually good enough as the ESR rapidly moves from a clearly acceptable to a clearly unacceptable level; an ESR of over a few ohms (less for a large capacitor) is unacceptable.

In a practical circuit, the ESR will be much lower than any other resistance in parallel with the capacitor, so it is not necessary to disconnect the component, and an in-circuit measurement can be made. Practical ESR meters use a voltage too low to switch on any semiconductor junctions that may be present in the circuit, which might present a low "on" impedance that would interfere with measurements.

It is easy to check ESR well enough for troubleshooting by using an improvised ESR meter comprising a simple square-wave generator and oscilloscope, or a sinewave generator of a few tens of kilohertz and an AC voltmeter, using a known good capacitor for comparison, or using a little mathematics.[2] A professional ESR meter is more convenient for checking multiple capacitors in rapid succession on a crowded board.

Other uses

An ESR meter is more accurately described as a pulsed or high-frequency AC milliohmmeter (depending upon type), and it can be used to measure any low resistance. Depending upon the exact circuit used, it may also be used to measure the internal resistance of batteries (many batteries end their useful life largely due to increased internal resistance, rather than low EMF. However, an ESR meter with back-to-back protective diodes across its input cannot be used to measure batteries), contact resistance of switches, the resistance of sections of printed circuit (PCB) track, etc.

While there are specialised instruments to detect short-circuits between adjacent PCB tracks, an ESR meter is useful because it can measure low resistances while injecting a voltage too low to confuse readings by switching on semiconductor junctions in the circuit. An ESR meter can be used to find short-circuits, even finding which of a group of capacitors or transistors connected in parallel by printed circuit tracks or wires is short-circuited. Many conventional ohmmeters and multimeters are not usable for very low resistances, and those that are often use too high a voltage, risking damage to the circuit being tested.

Tweezer probes are useful when test points are closely spaced, such as in equipment made with surface mount technology. The tweezer probes can be held in one hand, leaving the other hand free to steady or manipulate the equipment being tested.

Limitations

  • An ESR meter does not measure the capacitance of a capacitor; the capacitor must be disconnected from the circuit and measured with a capacitance meter (or a multimeter with this capability). Excessive ESR is far more likely to be an identified problem with aluminium electrolytics rather than out-of-tolerance capacitance, which is rare in capacitors with acceptable ESR.
  • A faulty short-circuited capacitor will incorrectly be identified by an ESR meter as having ideally low ESR, but an ohmmeter or multimeter can easily detect this case, which is much rarer in practice than high ESR. It is possible to connect the test probes to an ESR meter and ohmmeter in parallel to check for both shorts and ESR in one operation; some meters both measure ESR and detect short-circuits.
  • ESR may depend upon operating conditions (mainly applied voltage, temperature); a capacitor which has excessive ESR at operating temperature and voltage may test as good if measured cold and unpowered. Some circuit faults due to such intermittent capacitors can be identified by using freeze spray; if cooling the capacitor restores correct operation, it is faulty.
  • An ESR meter may be damaged by connection to a capacitor with significant voltage across it, either because of residual stored charge or in a live circuit. Protective diodes across the input will minimise this risk, but then the meter can no longer be used to measure battery internal resistance.
  • When an ESR meter is used as a milliohmmeter, any significant inductance present between the test probes will make measurements meaningless. For example, an ESR meter is unsuitable for measuring the resistance of transformer windings because of their inductive characteristics. This effect is significant enough that test probes with coiled cords should not be used due to their inductance.

References

  1. Jump up ^ Example of high-ESR capacitors causing voltages to rise in a circuit and destroy components. High ESR capacitors cause "5V dropping quite low and causing every other voltage to go sky high (and doing things like frying the HDD with upwards of 15V rather than 12V, and frying the tuning agc transistor with upwards of 36V instead of 30V)."
  2. Jump up ^ Stephen M. Powell (2000). "99 cent ESR test adapter". Retrieved 2012-03-10. Unknown parameter |description= ignored (help)
How to choose an ESR Meter
Why a technician needs an ESR meter
Troubleshooting a circuit requires an investment
in quality equipment. There are no shortcuts.
Without the correct equipment, a hobbyist-tec
hnician could damage your equipment beyond
repair, notwithstanding the fact that he is
incapable of diagnosing the original fault.
Today, a bare minimum of diagnostic equipmen
t is a good-quality oscilloscope, a high-quality
Analog Multimeter, a high-quality Di
gital Multimeter, and an ESR Meter.
Without these 4 basic pieces of equipment, a tec
hnician cannot be considered as serious in the
trade.
I will discuss here the benefits of the ESR meter,
an indispensable tool for taking care of circuit
problems at their source.
Many times, I have received units for repair, in wh
ich the failed part appears to be quite obvious –
a semiconductor transistor or IC. Simple - just
replace the semiconductor and return it to the
customer. But after a few weeks or months, it fails again, resulting in wasted comeback time, and
reduced trust from your customer.
The facts are quite simple – semiconductors are i
nherently very reliable and do NOT just fail willy-
nilly.
There is usually a clear underlying
cause for that failure – heat.
That heat is generated by either:
1.
Insufficient cooling ventilation (a manufacturin
g design fault and beyond the scope of this
article), or much more likely,
2.
Unstable current due to aging capacitors.
So, unless the cause of that semiconductor failure is
taken care of, at the same time that the actual
semiconductor is replaced, there WILL be repeat failures.
The most useful tool for diagnosing failing capacito
rs is the ESR meter. It measures the Equivalent
Series Resistance (the aging capacitor starts to be
have like a resistor, impeding current erratically),
and it measures it In-Circuit, so no ti
me-consuming desoldering is necessary.
A Capacitance Meter is not useful at all in thes
e cases, as a failing capacitor may still show an
acceptable level of capacitance.
I have tried a number of ESR meters on the market,
and this is my objective conclusion as to the
most capable and user-friendly unit for a techni
cian to use. As I write this, I have used these
meters for well over two years on my very-busy te
st-bench, so I can assume with some certainty
that this is how a busy technician is also going
to feel about using these on a day-to-day basis.
Australian Bob Parker pioneered the ESR meter, and
although his original
units are no longer
available, 2 companies licensed his tec
hnology to continue his legacy today.
I evaluated the following units:
1. EVB ESR meter (European-manufactured
licensee of Bob Parker's technology)
2. Anatek Blue ESR meter (USA-marketed – po
ssibly Far-East manufactured licensee of Bob
Parker's technology)
3. PEAK Atlas ESR meter (UK-manufactured SMD desig
www.ebay.com/itm/281237304221
___________________________________________________________________
Features:

* Graphic display tubes symbols and pin order. Glance.

* Add boot voltage detection function
* Automatic detection of NPN and PNP transistors, N-channel and P-channel MOSFET, diodes (including dual diode), thyristors, transistors, resistors and capacitors and other components,

* Automatic test out the pin element and displayed on the LCD
* Can be detected to determine the transistor emitter forward bias voltage of the transistor, MOSFET protection diode and the amplification factor of the base
* Measure the gate threshold voltage and gate capacitance of the MOSFET
* 12864 Chinese LCD monitors use (128 * 64 dot dots)
* High test speed, valid component test: 2 seconds (except in the larger capacitor of large capacitance measurement also takes a long time, the measured time of one minute is normal)

* One button operation, power-on test, get a key.

* Added fast shutdown button.

* Power consumption off mode
* Auto power off function to avoid unnecessary waste, saving battery power, improved battery life.

_______________________________________________________
Corrective steps : Short three test hook into the test , the screen prompts correction steps. When prompted to disconnect short time off the hook three tests . Continue to walk without human intervention. When prompted , please access 100NF 1-3 feet above the capacitor when the access and distribution correction capacitor 105. Then the program will automatically enter the next step. Until the end of the correction restart . The end of the correction.

This is a reference foreigner Markus F ( according to the circuit diagram presumably ) the ATMEGA328 transistor tester program modification . Store the original author weiweitm and shopkeepers from the summer of 2013 the groundbreaking transplant 12864 Chinese LCD screen, increased multi- speed automatic correction procedures , graphical display of the original graphic pin order .
Markus F1602 LCD gives the following version of the instructions for your reference.

1 . Using ATmega8, ATmega168 or ATmega328 microcontroller.

2. 2x16 character LCD display results.
3 . One button operation , automatic power off.
4 . Shutdown current is only 20nA, support battery operation.
5. A low-cost version without the crystal , auto power off. 1.05k ATmega168 or ATmega328 version of the software when no measurement to reduce power consumption in sleep mode .
6. Automatic detection PNP and NPN bipolar transistor , N, P -channel MOSFET, JFET, diodes, dual diode , thyristor SCR.
7 . Automatic detection pin layout.
8. Current amplification factor of bipolar transistors and measuring the threshold voltage emitter junction .
9. Darlington transistor may be identified by the amplification factor of the high threshold voltage and high current .
10. For bipolar transistor , MOSFET protection diode testing.
11. And measuring the threshold voltage of the MOSFET gate capacitance .
12. Supports two resistance measurements and symbols show the highest four numbers and units. Both ends of the resistor symbol is shown connected to the tester probes number (1-3 ) . Therefore, the potential can also be measured . If the potentiometer is adjusted to its end , the tester can not distinguish the two ends of the pin and the middle .
13. Resistance measurement resolution is 0.1 ohm , the highest measured value 50M ohms.
14. Can be detected and measured with a capacitor . Maximum four digits and units. Value can be from 25pf (8MHz clock , 50pF @ 1MHz clock ) to 100mF. Resolution up to 1 pF (@ 8MHz clock ) .
15. For the above values ​​can 2UF capacitor equivalent series resistance (ESR) capacitor value measurements. Resolution of 0.01 ohms and a two-digit numeric display . This feature requires at least 16K Flash ATMEGA (ATmega168 or ATmega328).
16. Two diodes can display symbols in the right direction . Further, the display forward voltage drop.
17. LED detection diode forward voltage drop is much higher than normal. Dual LED detected as double diodes.
18. Zener diode can be detected if the reverse breakdown voltage is less than 4.5V. This is displayed as two diodes , can only be determined by the voltage . Diode symbol is the same around the probe , in this case you can 700mV threshold voltage near real identification diode anode !
19. **** This annual understand , do not turn the ****
If more than three diode -type parts detection, failure to establish the number of diode display another message . This will only happen if the diode is connected to all three probes and at least one diode . In this case , you should only connect the two measuring probe and start again , one by one.
20. Measuring a single diode reverse capacitance value. Bipolar transistors also can measure , if you connect the base and collector or emitter .
21. Only one measurement to find full-bridge connection .
22. Values ​​less than 25pf capacitor typically undetectable , but a diode in parallel with 25pf capacitor or at least parallel. In this case , you must subtract the part of the parallel capacitance values.
23. Less than 2100 ohm resistor will measure inductance, if you have at least 16K ATMEGA flash . Range from 0:01 mH than 20H, but the accuracy is not good. Measurement results show only a single component connection.
24. Testing time is about two seconds , only capacitance and inductance measurements will take a long time .
25. Software can set the number of measurements before the power is automatically turned off .
26. Built-in self-test function with selectable clock frequency of 50Hz signal to check the accuracy and waits for a call (ATmega168 and ATmega328).
27. Optional internal resistance and zero offset calibration of measuring equipment self-test capability of the output port (ATmega168 and ATmega328). Need a 100nF to 20uF capacitor connected to the compensation between analog comparator pins 1 and 3 of the offset voltage. This can reduce the measurement error than 40uF capacitor . With the same internal calibration capacitor voltage reference voltage to adjust the reference measurements was found inside the ADC gain.
If the test current exceeds the holding current , SCR and triac can be detected. But some current higher than the semiconductor SCR and triac tester can provide the trigger current . Available test current is only about 6mA! Note that all functions have only used single-chip program memory as more ATmega168.


____________________________________________________________

功能:

*图形显示管子符号和引脚顺序。一目了然。

*新增开机电压检测功能
*自动检测NPN和PNP晶体管,N沟道和P沟道MOSFET,二极管(包括双二极管)、晶闸管、
三极管、电阻器和电容器等元件,

*自动测试出元件的引脚,并显示在液晶上
*可以检测晶体管、MOSFET保护二极管等的放大系数和基数的确定发射极晶体管的正向偏置电压
*测量栅极阈值电压和栅电容的MOSFET
*显示器使用12864中文液晶(128*64个点阵点组成)
*较高的测试速度,有效期组件测试:在2秒(除在较大的电容器,
大电容的测量还需要较长时间,测量的时间为1分钟是正常的)

*一键操作,开机测试,一键搞定。

*新增快速关机按键。

*功率消耗关闭模式
*自动关机功能,可以避免不必要的浪费,节约电池能量,提高续航时间。

矫正步骤:短路三个测试勾,进入测试,屏幕提示校正步骤。当提示断开短接时候断开三个测试勾。继续走无需人为干预。当提示请在1-3脚接入100NF以上电容时候,接入配送的矫正电容105.之后程序会自动进入下一步。直到矫正结束重启。矫正结束.

这个是借鉴老外Markus F(根据电路图推测)的ATMEGA328的晶体管测试仪程序修改。店内原装作者weiweitm和店主从2013年暑假开始动土,移植12864中文液晶屏,增加多档自动校正程序,图形化显示原件图形引脚顺序。
下面给出Markus F1602液晶显示版本的说明供大家参考。

1。采用ATmega8,ATmega168或ATmega328微控制器。

2。2x16字符液晶显示器显示结果。
3。一键操作,自动关闭电源。
4。关断电流只有20nA,支持电池操作。
5。低成本的版本不用晶振,支持自动关闭电源。1.05k版本软件的ATmega168或ATmega328在没有测量时用睡眠方式来降低电源消耗。
6。自动检测PNP和NPN型双极晶体管,N、P沟道MOSFET,JFET,二极管,双二极管,晶闸管可控硅。
7。自动检测引脚布局。
8。测量双极型晶体管的电流放大系数和发射结的阈值电压。
9。达林顿晶体管可以通过高阈值电压和高电流放大系数识别。
10。对双极型晶体管,MOSFET的保护二极管的检测。
11。测量MOSFET的阈值电压和栅极电容值。
12。支持两个电阻的测量和符号显示,最高四位数字和单位显示。显示的电阻符号两端是连接的测试仪探针编号(1-3)。所以电位器也可以测量。如果电位器调整到它的一端,测试仪不能分辨中间和两端的引脚。
13。电阻测量的分辨率是0.1欧姆,最高测量值50M欧姆。
14。可以被检测和测量一个电容器。最高四位数字和单位显示。数值可以是从25pf(8MHz时钟,50pF@ 1MHz的时钟)到100mF。分辨率可达1 pF(@ 8MHz时钟)。
15。可以对于2UF数值以上的电容器的等效串联电阻(ESR)电容值测量。分辨率为0.01欧姆和显示两位数数值。此功能要求至少16K闪存ATMEGA(ATmega168或ATmega328)。
16。可以对两个二极管显示正确方向的符号。此外,显示正向压降。
17。LED检测为二极管,正向压降比正常高很多。双发光二极管检测为双二极管。
18。齐纳二极管可以被检测到,如果反向击穿电压低于4.5V。这将显示为两个二极管,只能通过电压确定。探头围绕二极管的符号是相同的,在这种情况下,你可以通过700mV附近的阈值电压识别二极管真正的阳极!
19。****这条每年明白,不翻了****
如果超过3个二极管类零件检测,建立二极管数目显示另外失败的消息。这只会发生,如果二极管连接到所有的三探针和至少有一个是型二极管。在这种情况下,你应该只连接两个探针和启动测量再次,一个接一个。
20。测量单个二极管反向的的电容值。双极型晶体管也还可以测量,如果你连接基极与集电极或发射极。
21。只需要一次测量找出全桥的连接。
22。数值低于25pf电容器通常检测不到,但可以与一个二极管并联或至少25pf电容器并联。在这种情况下,你必须减去并联电容值的部分。
23。电阻低于2100欧姆会测量电感,如果你的ATMEGA至少具有16K闪存。范围将从0:01mH超过20H,但精度不好。测量结果只显示单一元件连接。
24。测试的时间是大约两秒钟,只有电容和电感测量会需要较长的时间。
25。软件可以设定电源自动关闭前的测量次数。
26。内建自检功能与可选的50Hz信号检查的时钟频率准确性和等待调用(ATmega168和ATmega328)。
27。可选设备校准端口输出的内阻和零失调自检能力的测量(ATmega168和ATmega328)。需要一个100nF到20uF电容连接到引脚1和引脚3之间补偿模拟比较器的失调电压。这可以减少40uF以上电容器的测量误差。用相同的电容器内部校正电压参考电压被发现调整内部参考测量ADC的增益。
如果测试电流超过维持电流,可控硅和双向可控硅可以被检测到。但是一些半导体可控硅和双向可控硅比该测试仪能提供的电流更高的触发电流。可提供的测试电流仅约6mA!注意,所有功能仅用于有更多的程序存储器的单片机如ATmega168。

___________________________________________________________________

Features:


  • 1,2013 latest M328 version of the software ,more functions.

    2,Use 8MHz external crystal , better measurement accuracy.

    3.Backlight LCD display,only 2mA when stand by.

    4,Mainchip is the DIP, easy to DIY, update the mainchip .

    5,Using 9V battery (Not inlcuded) Need open sheel then install battery

    NEW Function:
    1:Automatic detection of NPN and PNP transistors, n-channel and p-channel MOSFET, diode (including double diode), thyristor, transistor, resistor and capacitor and other components
    2: Automatic test the pin of a component, and display on the LCD
    3:Can detect the transistor, MOSFET protection diode amplification coefficient and the base to determine the emitter transistor forward biased voltage
    4: Measure the gate and gate capacitance of the MOSFET threshold voltage
    5:Use 12864 Chinese liquid crystal display with green backlight
    Size:140*90*55MM
    Specifications: For you reference
    1,One -button operation, automatic shutdown .
    2,Only 20nA shutdown current.
    3,Automatically detect NPN, PNP bipolar transistors , N -channel and P -channel MOS FET, JFET , diodes , two diodes, thyristors small power unidirectional and bidirectional thyristor.
    4,Automatic identification components pin arrangement .
    5,Measuring bipolar transistor current amplification factor and base - emitter threshold voltage.
    6,Via the base - emitter threshold voltage and high current amplification factor to identify Darlington transistors.
    7,Can detect bipolar transistors and MOS transistors protection diodes.
    8,Measuring the gate MOS FET threshold voltage and the gate capacitance.
    9,Can simultaneously measure two resistors and resistor symbol is displayed. Displayed on the right with a decimal value of 4 . Resistance symbol on both sides shows the pin number. So you can measure the potentiometer. If the potentiometer wiper is not transferred to an extreme position , we can distinguish the middle and both ends of the pin.
    10,Resistance measurement resolution is 0.1 ohms , 50M ohms can be measured .
    11,Can measure capacitanceCan measure capacitance of 30pF-100mF , resolution 1pF.
    12.2uF more capacitors can simultaneously measure the equivalent series resistance ESR values. The two can be displayed with a decimal value , resolution 0.01 ohms.
    13,Can be in the correct order and the diode symbol display two diodes, and gives the diode forward voltage.
    14.LED is detected as a diode forward voltage higher . Combo of the LED is identified as two diodes.
    15,Reverse breakdown voltage is less than 4.5V Zener diode can be identified.
    16,Can measure a single diode reverse capacitance. If the bipolar transistor connected to the base and collector or emitter of a pin , it can measure the collector or emitter junction reverse capacitance .
    18 can be obtained with a single measurement rectifier bridge connection.
    Notice: Before measuring capacitance , the capacitor must be discharged , otherwise very likely damage the meter .
12864 LCD Transistor Tester Diode Triode Capacitance ESR Meter MOS/PNP/NPN

以下为第一版资料供参考。=> The following is the first edition of the information for reference.











Description:
  • Features:

    1,2013 latest M328 version of the software ,more functions.

    2,Use 8MHz external crystal , better measurement accuracy.

    3.Backlight LCD display,only 2mA when stand by.

    4,Mainchip is the DIP, easy to DIY, update the mainchip .

    5,Using 9V battery (Not inlcuded) Need open sheel then install battery

    NEW Function:
    1:Automatic detection of NPN and PNP transistors, n-channel and p-channel MOSFET, diode (including double diode), thyristor, transistor, resistor and capacitor and other components
    2: Automatic test the pin of a component, and display on the LCD
    3:Can detect the transistor, MOSFET protection diode amplification coefficient and the base to determine the emitter transistor forward biased voltage
    4: Measure the gate and gate capacitance of the MOSFET threshold voltage
    5:Use 12864 Chinese liquid crystal display with green backlight
    Size:140*90*55MM
    Specifications: For you reference
    1,One -button operation, automatic shutdown .
    2,Only 20nA shutdown current.
    3,Automatically detect NPN, PNP bipolar transistors , N -channel and P -channel MOS FET, JFET , diodes , two diodes, thyristors small power unidirectional and bidirectional thyristor.
    4,Automatic identification components pin arrangement .
    5,Measuring bipolar transistor current amplification factor and base - emitter threshold voltage.
    6,Via the base - emitter threshold voltage and high current amplification factor to identify Darlington transistors.
    7,Can detect bipolar transistors and MOS transistors protection diodes.
    8,Measuring the gate MOS FET threshold voltage and the gate capacitance.
    9,Can simultaneously measure two resistors and resistor symbol is displayed. Displayed on the right with a decimal value of 4 . Resistance symbol on both sides shows the pin number. So you can measure the potentiometer. If the potentiometer wiper is not transferred to an extreme position , we can distinguish the middle and both ends of the pin.
    10,Resistance measurement resolution is 0.1 ohms , 50M ohms can be measured .
    11,Can measure capacitanceCan measure capacitance of 30pF-100mF , resolution 1pF.
    12.2uF more capacitors can simultaneously measure the equivalent series resistance ESR values. The two can be displayed with a decimal value , resolution 0.01 ohms.
    13,Can be in the correct order and the diode symbol display two diodes , and gives the diode forward voltage.
    14.LED is detected as a diode forward voltage higher . Combo of the LED is identified as two diodes.
    15,Eeverse breakdown voltage is less than 4.5V Zener diode can be identified.
    16,Can measure a single diode reverse capacitance. If the bipolar transistor connected to the base and collector or emitter of a pin , it can measure the collector or emitter junction reverse capacitance .
    18 can be obtained with a single measurement rectifier bridge connection.
    Notice: Before measuring capacitance , the capacitor must be discharged , otherwise very likely damage the meter .


  • Package Contents
    100% Brand New
    NEW Transistor Tester Diode Triode Capacitance ESR resistance Meter MOS PNP NPN




versió per imprimir