#108 Building and testing an eBay Transistor Tester kit

This little kit can be bought on eBay and other places for very little money but no documentation comes with it. In this video, I give some hints on building and using it. The tests are all based on the firmware 1.12K that was originally in the ATMega 328P. This firmware is quite usable but not the latest. There will be a follow-on video about changing the firmware

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00:00 Intro
03:35 better resistors
05:06 tips for building
14:27 first tests
15:24 schematic
18:40 properly working now
19:32 calibration
22:20 test menu
23:43 oscillator & extensions
27:23 capacitor test
29:37 inductor test
30:55 resistor test
33:41 PWM test
34:25 Voltage test
35:09 Conclusion

[galileo_rs]

First time that I have seen someone read the manual when building this kit :) Overclocking the device and replacing the voltage standards is useful endeavour. Also quite capable at measuring small inductances when used with a reference cap.

[keithking]

A must have bit of equipment for any Hobbiest/professional 😊😊

[td]

Another excellent HWCave video = woot! As you know, these testers have a long-standing, decent reputation within the EE hobbyist community as Go-NoGo testers. I use mine, extensively, to prove all of the components that I have gathered for a project, before assembly. I mostly use the ZIF socket, but I did build a set of test "leads." It has a single row of three header pins that sits in the ZIF socket. Each pin of this header has an individual wire for each of the three pin functions. Each individual wire is then terminated with a single header pin. The individual header pins then serve as test probes. This pigtail serve the same purpose as the additional screw terminals that you added. I need to build another lead set that has alligator clips. The tester is super-excellent, for GNG proofing, as said, and quickly determining the pinout of a component. Mine sits on my bench at the ready at all times and gets used in most every build/test session. Though I would not use it for precision work, it is a fine addition to any bench. It is a good Swiss-Army-Knife for hobbyist on a limited budget, because it has so many extra functions, such as the function generator and counter. Oh... Mine came with a clear case with a space for a battery. I replaced the battery clip with a barrel socket and power the unit from my PSU. This left room to add an additional testing circuit. I picked a Colpitt's Crystal Oscillator to be able to to drive pill-can crystals. This makes it convenient to use the frequency counter function of the tester to check oscillators.

[johncoops]

These AY-AT kits are considered the best of the clones. Changing the 7550 voltage reference is a good upgrade, and if you change it to a decent one you are best to OMIT the TL431 (the firmware ignores the TL431).
Definitely try to use the best sets of input resistors (3:35) because the self calibration only calibrates based on the average values - the closer you can get the resistors, the less variation in tested values between the pins (eg: resistor between 1+2 reads the same as between 2+3).
Note that the values doesn't actually matter much, since you can adjust the "expected" value in firmware... it matters much more about how they are to each other (make sense?).
Oh, and for test leads, it's neater to use 2mm rather than 4mm banana jacks.
EDIT: Not sure why my other (even more helpful) post was deleted. Not cool!

[TheFalschspieler]

May I ask where your accent originates from? I really like to watch your videos because I learn a whole lot about electronics and components and secondly your voice and accent are really calming and this is pure relaxation for me.

[jumbo]

6:52 there is 6 pin tiny component on the left which is close to the edge and two other smd components
Are they presoldered?
I want to buy this tester but I can't solder smd component.

[jimquinn]

Proud to be first to thank you for this video.