EEVblog #1020 - Is A $7 LCR / Component Tester Any Good?

Is a $7 LCR Meter / Component Tester from Ebay any good?
Dave tests the M328 (LCR-T4) model component tester.

HUGE Forum Thread:

This group seems to maintain a version of the firmware:

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[DavidChen]

The original project name is AVR-Transistortester, opensourced firmware/schematic/documents maintained by German hacker Karl-Heinz Kübbeler.

[richfiles]

Testing a piezo speaker is particularly fun, as you can hear it probing at the part to determine it basically operates as a capacitor.
Really interesting to get to hear it go through the motions though.

[John_Ridley]

One of these is all I have for LCR meter, and it's more than good enough. All I need one for is to identify messed up electrolytics that have caused a power supply to fail. Finding an electrolytic that should be at 1 ohm ESR measuring 35 ohms is good enough.

[danielsullivan]

Thanks for looking into this! Saw the furore in the mailbag comments and it's good to see you addressing it :)

[bitrot]

I have that exact tester... It's true that the absolute measurements are a bit off, but it's fairly consistent when you repeat measurements, so it's great for matching components. I've used it to find the closest resistors in the pile, and to match MOSFET gain when rebuilding an amplifier. Fantastic bit of kit once you understand its capabilities and limitations.

[gtroc]

Dave, you can calibrate this device by shorting all 3 test points and pushing test. After a short process will ask you to remove short and at some stage ask to install a capacitor. Would be interesting how accurate it is after that process. Thanks for the vid!

[WisdomVendor]

Dave, a guy with a $9000.00 rolex watch was once told by a guy that had a $3.00 digital watch "Nice wrist watch, it seems to be only a few seconds off"

[edmart]

6:31
From product manual:
"The turn-on or turn-off voltage of the mosfet must be less than 5V, otherwise the measured result is only its equivalent parameters (diodes, capacitors, etc.)."

[FindLiberty]

I've had mine for several months; *cute!* _...added a power switch to prevent any parasitic sucking juice out of the 9v battery._

[kuhrd]

Many of these units also offer a way to calibrate them and once done are pretty much bang on. Some of the software versions also offer more accuracy depending on the external ADC being used onboard. I have a couple of these units and they come in really handy for testing salvaged parts or doing basic transistor or mosfet matching.

[Stefan_Payne]

Nice to see that you made an additional video about that device, thumbs up.

Oh and what you want with that is to test, if the component you put in is OK or not and if the replacement part is somewhat close to the original part.

[aszi]

If you press and hold the button a menu comes up with a number of functions including in-circuit ESR measurement for capacitors (without having to press the button each time), very useful.

[srduke]

I know I'm late to the party but I've got one of these and it's perfect, as you say, for checking pin outs on transistors etc. Certainly a lot quicker than trawling the net for data sheets. I also use it for checking that LEDs are working before soldering them to a pcb.

[JerryEricsson]

I have owned one of these for about 3 years now. Two years back I picked up one of those DIY Kit mini oscilloscope and put it together on the booth table of our RV. To sort out the parts for the kit I used my version (A bit more developed then yours) to sort the parts for assembly. It did a great job. Since I rarely use surface mount, I have soldered alligator clips on the pads so I can hook to parts that do not fit nicely in the plug deal. I use it very often and it has always done a great job for me.

[stephtronix]

I recycle hold electronic parts and i really like that meter. It makes it faster to identify the components so i can class them where they belong :)

[bveina]

We've just outfitted all our labs at my university with a variant of these. We use them as pinout checkers and magic smoke detectors. Saves tons of time helping students. I've also grabbed a 74xx chip tester for logic gates; same reason, check for the magic smoke.(no kid your chip isn't bad, you wiring is)

[yaidontknowwhattoput]

Lcr meters are super complex. The fact that this $7 jobby can get it done is astounding.

[pasixty]

Although considering the (shown) weaknesses of this device, you get a considerably good tester for an unbeatable price. We absolutely don't talk about high end precision in this class of pricing or manufacturing. In most cases the precision of the device is good enough to help you find out what you have plugged into the socket. Me and my friends ordered those from China. We like them.

[aidanfransen]

Good to see you following up on the last vid! At least our comments do not go unnoticed :)... also good to see you giving it a fair test :)

[topeye]

The inventors are: Markus Frejek and Karl-Heinz Kübbeler