$20 LCR ESR Transistor checker project

[at2marty]

I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.

That's good to hear.  I would be more-than-willing to contribute in any way that I can.

[neslekkim]

an interesting twist would be to make an arduino-shield that has all the hardware other than the mcu.

Cannot find more about this project, seems like website is down:
https://www.eevblog.com/forum/testgear/$20-esr-lcr-transistor-npn-pnp-mosfet-meter/msg234473/#msg234473

[Flump]

I really want to get an esr meter that can test in circuit
and also a transistor tester/semiconductor tester

but there is so many versions of these now i dont know what to get lol

[madires]

I really want to get an esr meter that can test in circuit
and also a transistor tester/semiconductor tester

The ESR in-circuit measurement was added in the firmware versions 1.10k and 1.12m . We (Karl-Heinz and myself) encourage everyone to give us feedback about the in-circuit ESR feature.

but there is so many versions of these now i dont know what to get lol

It's like standing in front of the shelves full of detergents in the super market :-) You can DIY or buy a clone. My recommendations are ATmega328 and a classic text based LCD module. Some clones come with a nice box but most lack the hardware options.

[Flump]

Thanks for the advice madires

I would like to buy one I am not good enough with electronics yet to make one

which would you say was the best out of the all in one ebay modules ?
i have a limit of about £30

[madires]

which would you say was the best out of the all in one ebay modules ?
i have a limit of about £30

There isn't any particular clone which is the best. Select the one which suits you most (test pads / textool socket / probe leads or whatever you prefer). Another thing to watch out for is the ISP header (unpopulated in most cases) for flashing new firmware.

[Towger]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Yes, I am interested. I have been following this thread for ages now. The additional input protection along with the new support for in circuit ESR testing would make one very useful.
Are you going to design it through hole and/or SMT?

[con-f-use]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

I'm intrested, too.

[BravoV]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Vincent, I'm in, thanks ! 

[neslekkim]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Would be very interrested!
Will it use the 328 or an bigger mcu?, ref this:

I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.

[apelly]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Yes please! I was going to make one myself, but that will take ages considering the rate at which I'm currently getting things done.

[KD0CAC John]

I having wanting to build one of these also , but kinda waiting for one design settles , with some of the newer ideas coming on now , I just need to start
So if you have room , put me on the list also ?
Thanks
John

[Shock]

I want to make a nice board for these.
Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Count me in for a couple.

From what I have seen a larger memory, decent resistors, programming header, crystal, battery, external power, backlighting and zif socket are all highly desirable features. As Madires mentioned going with a non standard display can add complexity for no benefit.
I highly recommend going with the display I have pictured, not only are they cheap, easy to source and replace but they look great.

I think the zif socket outside the enclosure works well also like a eprom programmer. Then insert a small pcb into the zif socket for smd devices, or wires for probes etc. Here is my idea I was thinking of, being that you can easily detach the display and it doesn't interfere with the main board.
I was going to make a modular sub board with the zif socket but later decided mounting everything from the zif is better.

[madires]

From what I have seen a larger memory, decent resistors, programming header, crystal, battery, external power, backlighting and zif socket are all highly desirable features.

And a bunch of options:
- PWM backlight (just hardware)
- 2.5V voltage reference (if not using a MCP1702 or something similar as voltage regulator)
- protection relay (for discharging caps)
- high voltage Zeners (up to 50V DC, boost converter, requires 2 dedicated test pins)
- frequency counter (extra input)

[Fluxed Matter]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

How about local pickup? Or just drop it in the mail.


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[jackryan315]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

count me in for a board or two.

[amtpdb]

What is the cost of a board and shipping to San Bernardino. What would you think the total cost of a completed board would be? When would this happen and when would you have a picture of a completed board?
Thanks

[Fluxed Matter]

I think we should create a new thread about fe's new board so as not to derail this one.


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[true]

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

I'm just a state over

[madires]

Please use private mail for your "me too"!

[vindoline]

Hi Madires,

I've finally gotten around to finishing up my version of this great "transistor tester" project. I've flashed your latest firmware (1.12m) and the hardware/software seem to be working fine! The only components that I feel I can measure with any real accuracy/precision are resistors. I used a series of 1% metal film resistors from 1R to 1M, measured them with 2 different Fluke DMM's and then the new "transistor tester" The unit is remarkably accurate and agrees with the Flukes between 10R and 1M. Below 10 ohms the unit reads 5-10% high.

My question is about the inductance measurement. For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor. For higher value inductors, the measured value reads low (compared to the "nominal value" of the parts). I don't have another LCR meter to verify the actual inductance with, so the readings may actually be just fine. In any event, could you comment on the general measurement range and accuracy of the inductance measurement? Thanks!

[paulie]

i am still amazed at the capabilities of this project. it is by far my most useful piece of test equipment. working with geiger counter designs it has proven a huge time saver checking hv transistors, hv caps, and inductors to see if they are still alive (usually NOT! lol).

even my cheap $1 harbor freight dvms do pretty good with semiconductors so one thing i would love to improve is ability to measure lower value inductance and caps. even if it involves some minor hardware changes. i plan to dig into that pdf to get more up to speed on the theory but could also use some hints as to current ranges and how to improve lower value measurements.

[dannyf]

For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor.

An inductor with infinite inductance is a resistor.

[madires]

I used a series of 1% metal film resistors from 1R to 1M, measured them with 2 different Fluke DMM's and then the new "transistor tester" The unit is remarkably accurate and agrees with the Flukes between 10R and 1M. Below 10 ohms the unit reads 5-10% high.

That make sense since an additional measurement method is used for resistors less than 10 Ohms. Does anyone else also got those high values for resistors < 10 Ohms? I'm testing the firmware with 3-4 different testers to detect any issues, but sometimes there are still some surprises.

My question is about the inductance measurement. For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor. For higher value inductors, the measured value reads low (compared to the "nominal value" of the parts). I don't have another LCR meter to verify the actual inductance with, so the readings may actually be just fine. In any event, could you comment on the general measurement range and accuracy of the inductance measurement? Thanks!

The inductance measurement is quite limited by the maximum test current and the method used. It even runs the ATmega out-of-spec for some µs for low inductances. The supported range is roughly 100µH up to 1H and the resistance has to be less than 2kOhms. With a clock rate of 16MHz you'll get a small improvement (factor 2). Therefore the inductance measurement is just for checking the order of magnitude and not for measuring the exact value. Any LCR meter will give you more precise results.

[madires]

even my cheap $1 harbor freight dvms do pretty good with semiconductors so one thing i would love to improve is ability to measure lower value inductance and caps. even if it involves some minor hardware changes. i plan to dig into that pdf to get more up to speed on the theory but could also use some hints as to current ranges and how to improve lower value measurements.

The k-firmware goes down to 30pF and the m-firmware down to 5pF. With the current hardware design and the implied measurement methods low value measurements aren't really feasable. The oscillator method (frequency counter) or the AC generator method (U and I) are suited much better for that purpose. That's something for a Tester+ ;-)