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

hi this is going to be a follow-up video to my previous mailbag one where right at the end of the mailbag somebody sent in this thing which looked like just some no-name generic tester aboard from ebay they were like no instructions no nothing there's no labeling on it you know and it just like what the hell was this thing and I just sort of you know brush to the side and quite rightly I copped a lot of flack for this so yep sorry I should have at least put it through its paces so here we go we're going to take a look at one of these $7.00 I you can might even be able to get it slightly cheaper $7.00 delivered LCR meter slash transistor tester slash component analyzer slash whatever you want to call this thing now I always aware that these kind of things existed but I hadn't hadn't been following the 156 page eevblog forum thread on this that's not post that's pages so please forgive me that I'm not going to go back and read the entire hundred and fifty-six page thread about these things now this particular one I've found it on eBay and it's the Emma three to eight but it goes under various different names and it calls itself your parent up calls itself the Emmet tester like there's no other like information on here and that's one of the things like I know it's only seven bucks but is it too hard to actually you know silkscreen on there what this thing actually does or something like that I don't know it would have been handy anyway let's get into apparently it's a component tester and apparently it's pretty good these have a big following lots of fanboys out there and people wanted me to test it out so let's give it a go this is this particular M three to eight one and yes I do have a brand new battery because if you noticed in the mail bag if I use one that had a much lower voltage which by the way does not show up like a seven point something volts there you go the contrast is just unreadable on this thing even though it doesn't give you a low battery warning error message so there's the first problem with this thing now I know that there are dozens and dozens of variations on this thing if not hundreds of variations on this thing people put them in their own do-it-yourself housings and all sorts of stuff I believe the one like the first one was like a regular to line 16 character LCD this is a particular graphics based one and we can whack a component in here and that's what the numbers are there for it's got three different terminals and it's got presumably duplicated over here I haven't tried it for a power transistor pads and you can plug a component into any part of that just power it on and it simply does it test there it is 100 ohm resistor between pins 1 and 3 beautiful so yes I have no idea what firmware version this is running want very what you know schematic of variant this thing is it's just a generic eBay M 3 to 8 so yeah take that as it is now one of the first problems I have with this thing is well this particular unit in particular is the backlight so let's switch it on and it's just like it's pissing away the power like why they need that backlight I've got a capacitor in there now a hundred n like a lot of that will be the backlight like why frustrating anyway this thing is really quite jazzy look if I put a transistor in there just got one out of the junk tin but junk bin what is it a B D one three seven I think it is let's pair it on and have a look and I do like the automatic nature of this it is very nice look at that it's automatically identified the transistor which you know base collector emitter on which particular pin there and it gives us the hf e and the forward voltage curve but at what current I don't know so we can actually take that flip it around and see if it works the same you basically gotta press the button each time it just reap hours it basically there we go look at that beautiful so there's obviously a lot of refinement that's gone into this firmware and I'm sure a firmware is totally different across many different variants of this the countless different variants of this product but this one I mean Joe I tried resistors capacitors and transistors now and it's just very nice so yeah I'm huge thumbs up to this where this originally comes from who's writing this code who's building it I don't know the history behind this is it's probably some huge mashup of code over time I don't know if anyone's like that does anyone know the original developer of this but I've seen projects like this for going back you know decades in the magazines and things like that so I don't think it's particularly new and I guess I don't mind the use of ayas if socket like this for testing it's okay you know like it's fine especially for like seven bucks I remember like seven bucks delivered I remember when the ZIF socket like this used to cost seven bucks and text tool it doesn't have 3m on it doesn't so it's probably just something yeah one hung low variant anyway I'm gonna try and fool the crap out of this thing um because I don't know what range of stuff at tests the I'll plug in a 7805 I don't expect it to work at all it'll probably confuse it and say it's something else but let's try it no no unknown or damaged part there you go it didn't it went well that's outside the bounds of what I know about I only know about these particular parts and it doesn't test like any ovens so that's pretty groovy don't mind that at all come on can't fool it count full it surely it's going through all its routines now it doesn't know what that is nice doesn't know what a red LED is there you go you can see it pulsing ah there you go and well it says it's a diode which is exactly what it is it's just a light emitting diode and two volts and it says it even gives you the capacitance for the diode for path isn't that Jersey so I'll just repeat that I turned it around and put it in different ones yet that's pretty repeatable nice green diode there sweet we'll try a VN 10k MOSFET here but why fail it thinks it's an NPN transistor hmm so that's interesting it knows it's acting like a transistor which it is it's just a MOSFET and it is an N channel MOSFET so it's got that right and the HN it knows that the gain is massive but it hasn't identified that it's actually a MOSFET instead of a bipolar and as for capacitors it just gives us capacitance but I had it before it was showing up what's called V loss which a it was 0.1% which I like I can't get it to do it again but I swear it came up there it is no point one percent so I assume that's the dissipation factor so let's compare that with a real LCR tester and see what we get ninety four point eight at one kilohertz I believe the test frequency is yeah it's not quite there but for ballpark measurements like a component identification I mean it's just fine so I'm not going to quibble over that and as for that voltage lost there there you go dissipation factor you know the point said point one percent 0.03 you're enough ah-ha it starts to give us more info if we had put an electrolytic in there I was wondering if it was going to do the ESR and certainly it does 1 point 6 ohms forty eight point eight eight with a 1% dissipation factor and we're getting one point six owns there which is pretty good for the ESR once again for component ID it's it's doing the job just fine okay so let's try the resistance over a entire range here I wouldn't quibble over anything less than 1 ohm I haven't included test leads here so that's just fine ten point eight hundred and one thousand and nine ten point Oh 801 getting a little bit out but you know what Meg's still pretty schmick see if we can do ten Meg hey that's not bad at all I am liking that let's say let's go out to say something difficult like 50 Meg that's not easy to yet no unknown part so what does it do go up to you know 20 mega so that's fine that's great so that seems to be reasonably accurate over the entire range don't mind that at all okay let's try a big cap 2200 microfarad electrolytic let's go it's I measured at 1869 on my LCR meter and I was at 0.05 ESR 0.18 it's a little bit out and 1965 but like it doesn't matter I'm happy with that just for component identification that's a winner but you saw it there had point nine percent V loss and like that doesn't match anything doing with any sort of at one kilohertz the dissipation quality factor of this thing so I'm not sure what's going on there now it's supposed to be able to measure our MOSFETs but of course you saw a tyre fail with that V in 10k one there so let's put in this IRF 6/10 and give that a bowl I'll be very impressed if it can it's supposed to do the a Wow okay consider me suitably impressed look at that that's impressive n channel mosfet even get like in it shows the internal a diode and let's whack that around like that okay so I didn't like the V in 10k one but it certainly does the business on this i RF 610 is very impressive and really you don't care about the parameters that much is not a you know a precision bit of kit it's a component identifier essentially so you know that's pretty much all you want let's try one again we've got an IR f9 double one o P channel MOSFET so let's give that one a bill nice haha that's that's worth its weight in gold and let's do a D soldered salvaged 50 no6 shall we pretty standard part on I can't handle the Salter on the pins all that well let's give that a bell hang on might not be making contact ah works a treat winner winner chicken dinner okay let's try a surface mount bipolar he got a double to double to for those play at home let's if we can that's me I'll see I made a turning off so I'll hold it down on there I don't like those pads but it's obviously working in this case neat all right let's try 3.9 volt Zener diode see what we get Hey look at that that is bang on to what you want like it doesn't tell you it's a Zener diode but it's implying it's a Zener diode because it's got the forward voltage yet it's not quite there 3.9 volt second only going at these low voltages for these levels then it's going to depend heavily on the test current so yeah don't like that's good enough right and then it knows that the diode in the opposite direction is your standard silicon drop like that so from that you can infer it's a you know three point five ish volt Zener no just got another little ceramic cap here but you can see that I'll show you that the they dissing what the supposed dissipation factor is going to be you know it it's fairly out on this so I wouldn't really take that as anything meaningful you know 0.6% V loss you know it's near enough on the capacitance just use it for component ID it seems to be grossly out on depends maybe there's a sweet spot of capacitance where you know it does fairly well on that but you know some I've measured just aren't anywhere even in the ballpark and I just did a little little are thousand micro Henry or one milli Henry inductor surface-mount inductor there just by holding it on there and that did a reasonable job there you go there's the resistance of that and the adduct answer that at one kilohertz so it's pretty close nice and that's a 10 micro Henry inductor but it doesn't seem to really look at the resolution there it's pretty terrible and it can't measure a 1 micro Henry at all it just thinks it's a resistor and well that's fine it's got a lower limit so there you go I'm actually are very impressed by this little thing it's amazing what you can get out of just a little 80 mega micro some very clever us software that's no doubt I've been much refined over time and a couple of passives and other stuff there's a couple of trainees in there a few diodes you know there's really nothing to these things and it you can build these yourself I'm like there are countless designs out there apparently and I'll link in the eevblog forum to this thing how 156 pages of it so for seven bucks deliver this thing is just magical um definitely get one but I'd recommend like maybe get like spending a bit more and getting one that has a case with proper banana Jack's on or something that you can plug you know little LCR type test leads into or something like that or you can make your own you can just buy the bare-bones one like this and you know you get rid of the ZIF socket or even have it on the front panel make your own case do what a 3d printed case do whatever make a little do-it-yourself project out of it cuz these things are quite impressive don't use it as a substitute for a real LCR meter to take you know quantitative measurements of parts um that's not what's it's for it's for you know a basically the component identify a go/no-go tester you know it gives you a ballpark figure it seems reasonably accurate though for various capacitances and resistances and it doesn't go that low in inductance and stuff like that but for transistor identification like I wouldn't be taking the beedo for granted and you know stuff like that so this is a large community of people actually you know hacking around with these things and changing the firmware and changing the design and you know doing their own builds and things like that which is fantastic so it's definitely worth having one of these things in your kid especially you know for the price if you're on a budget then you know seven bucks delivered for a component identifier and basic measure you know basic measurement tool like this just fantastic and almost go practically can't be beat and but there are tons of variations of this as I said so apparently can well some others I've read do i you know scr thyristors and stuff like that I don't have any of those handy here but it's impressive the amount of components that they can do and it can do it like MOSFETs like that that's just fantastic anyway hope you enjoyed that if you did please give the video a big thumbs up and as always discuss down below catch you next time you

Channel: EEVblog

Views: 642,082

Rating: 4.8837395 out of 5

Keywords: eevblog, video, m328, mt328, lcr tester, component tester, lcr meter

Id: 7Br3L1B80ow

Length: 15min 53sec (953 seconds)

Published: Tue Sep 05 2017