The Kuman was unreliable in checking LEDs as where the MK-168 did a good job. Most of the time I had to switch it off than immediately back on (test) then it worked. If sitting a white pressing the test switch it comes right on. I found the same SCR and Triac problem I had with the MK-168. To get around the ZIF socket problem I built my own adaptor as shown in the video. The case is almost too small to the point a could barely get the 9-volt battery into the tester. The ZIF socket is not soldered in and doesn't fit flush with the top of the case as shown below. This is understandable using a 9-volt battery. While it did check low power sensitive gate SCRs it couldn't check most SCRs and no Triacs I tried. The MK-168 had some bad internal solder joints I had to go into and fix. It displayed a picture of the device including internal diodes and pinout of transistor and MOSFETs, etc. The color display in the Kuman was nice cosmetically to the plain LCD display of the MK168. The Kuman checker has neither and is limited to small parts the fir the ZIF socket. The MK-168 with its 3-pin plug-in ZIF board and three clip cables makes checking large components such as TO-3 easy. Both are powered by a 9-volt battery and have auto power shutoff. They are useful for general information on components and for transistors and dual diodes identity pin connections. I own both models and discuss their use in the YouTube videos list below. Both check far more than just transistors, but a number of semiconductor and passive components as list below.īoth are available on Amazon as of 4-20-2018. The MK-168 and Kuman multifunction transistor checkers and the many related clones are inexpensive transistor checkers. I could have wished for a better SMD pattern.įor the money it is a good tester for leaded parts and acceptable for smd parts, but the defect diode symbol is confusing.Comparing ATmega328 Based Transistor Checkers There is also the 'problem' that any testing values shown for diodes, BJT and FETS are at unspecified conditions and the values will change with conditions. It can recognize the common semiconductors, but fails on some more special types. For passive parts the precision is fairly good. The tester will recognize many different components and show the values. When on the current consumption is 10mA to 27mA. It can detect normal fet transistors, but not a deflection transistor.Ĭomponents are tested with 5 volt signals. The faulty diode symbol is a bit confusing to see here.

There is not space for a transistor symbol on the display, the letters NPN or PNP are used instead. It do see the diode in the transistor, but not the resistor. Triac is spelled out and MT1 and MT2 is shows as 1 and 2. It cannot detect most SCR and triacs, because the tests currents are too small.

There is a bug in the symboles, one of the diodes are not programmed correctly. It cannot measure small inductors.ĭue to the 5 volt test voltage it cannot see zener diodes above 5 volt. With inductors it uses the resistor symbol, but shows a inductance in addition to the resistance. The display it not graphical, but because it is possible to program some characters it can show a useable symbol. The adapter has a smd pad, but with fairly limited functionality. It has 3 pins connected to each of the 3 terminal, one directly for ADC, the two other pins with different resistors between. The circuit is very simple, the microprocessor do everything. The display is a standard display with 2 lines with 16 characters.Īll the electronic is placed under the display. Inside it is made very nice with connectors and a circuit board designed for this box. The box has a connector for external power, but can also fit a 9 volt battery inside. It does also include a circuit board with a socket and a smd pattern. This tester is in a box with 2 mm connections, it includes test wires. This is a fairly universal component tester, it can recognize a lot of different component types and give some parameters for them.

Mk168 transistor tester