Low Cost Cap Tester, ESR, LCR 2018

[Shock]

My multimeter doesn't have the Relative delta mode, so how can I calculate the lead offset?

Connect the leads together and take a measurement. Then measure your capacitor and subtract the first measurement. Then convert the result to the ohms value (100mV per Ohm). It's easier than it sounds with practice but not as easy as the Bob Parker which automates this in software and a button press.

I may not understand it, but the "no protection" issue doesn't seem to be the big deal if we take the time to discharge the caps before testing them.

No protection means the first time you forget to turn the power off or discharge a cap large enough to damage the microcontroller you will be learning about ESR meter repair. It's an easy mistake to make, the more expensive and elaborate the ESR meter is the costlier it will be.

The real issue seems to be that it throws too much power on the circuit (someone says 9V vs some milli-volt for the in-circuit ESR meters) which might trigger the semiconductor, and even burns component. I read this in several places, including on Amazon comment that it should not be used in-circuit.

The real issue is you need to spend some more euro and buy the EVB. I only mentioned the Chinese AVR clone because of your budget constraints. I said myself is isn't really designed for in circuit testing, regardless of what someone on Amazon says.

[JDW]

For goodness sake, just buy a DE-5000.  It costs about US$100 (mine came with most of the accessories), but it's also one of the best handheld ESR meters out there.

[kripton2035]

For goodness sake, just buy a DE-5000.  It costs about US$100 (mine came with most of the accessories), but it's also one of the best handheld ESR meters out there.

I completely agree with that, but it's a precision instrument, and so not protected from beginner's mistakes...

[JDW]

But a true beginner who makes mistakes probably would be worse off trying to buy a kit and build it themselves.  So whether they get a DE-5000 or a kit, they are basically in the same boat.  It therefore makes the most sense to just get a precision instrument (only a $100 instrument, not a $1000 one) and be careful with it.  I am very careful with mine.  Same with my µCurrent Gold.  People who cannot be extremely careful are better off not testing ESR.  Seriously, imagine a 0.5F cap in the hands of a beginner who isn't careful!

[Shock]

But a true beginner who makes mistakes probably would be worse off trying to buy a kit and build it themselves.  So whether they get a DE-5000 or a kit, they are basically in the same boat.  It therefore makes the most sense to just get a precision instrument (only a $100 instrument, not a $1000 one) and be careful with it.  I am very careful with mine.  Same with my µCurrent Gold.  People who cannot be extremely careful are better off not testing ESR.  Seriously, imagine a 0.5F cap in the hands of a beginner who isn't careful!

Noones hating on the DE5000, it's the best bang for buck LCR/ESR.

It's just not the "best" tool for in circuit testing. The EVB meter (Bob Parker design) on the other hand is (almost) perfect for the job. Can get it preassembled, optional input protection, simple to operate, has schematics, replacement microcontrollers available, 100% repairable. If you wanted to you could even DIY everything but the microcontroller.

[JDW]

So you can actually connect the EVB (Bob Parker) meter to a circuit (disconnected from power) with huge, charged caps and all will be well?

Even if true, the "Testing Capacitors Out of Circuit" section at the bottom of this web page explains the practical reasons why you still may need to desolder and test caps outside the circuit, which is the only way I test ESR with my DE-5000.

[Shock]

So you can actually connect the EVB (Bob Parker) meter to a circuit (disconnected from power) with huge, charged caps and all will be well?

Sure want to up the game? Define "huge" then attach the DE5000 with no input protection and see what happens.

As I've been saying the Bob Parker design is intended for "in circuit" testing even though it doesn't discharge caps for you. The original kit handles ~50V max and Bob says on his website he has not heard of anyone damaging a meter after adding the diode protection mod on the input. You can read about this in the assembly manual.

Protection circuitry
Last but not least, the meter needs to be protected against being connected to charged capacitors. This  protection is partially provided by back-to-back diodes D3 and D4. If an external DC voltage (ie, a charged  capacitor) is connected, one of these diodes conducts and forces non-polarised capacitors C5 and C6 to charge up to that voltage. Additional protection is provided by C7, R12, D5 & D6 which stop excessive
input voltages from damaging transistors Q7 and Q8 in the pulse amplifier circuit.

In particular, diodes D5 & D6 acts as voltage clamps – D5 ensures that the voltage on Q7’s base cannot go  above 5.6V, while D6 ensures that this voltage cannot go below -0.6V. Finally, extra “heavy-duty” protection can be added by connecting a pair of back-to-back high-power diodes (not shown on the circuit)  between the test terminals.

Heavy-duty protection
To provide greater protection against connection to charged electrolytics, some kit builders have connected  an inverse-parallel pair of 1N5404 (or  similar) high-power diodes between the test lead sockets. So if you’re the kind who’s likely to connect the meter to the 120μF input filter capacitor of a 240V-powered   switching power supply without checking that it’s been properly discharged, this modification is for you.

Reportedly, this protects the meter quite well, although it can result in the probe tips being blown off by large charged capacitors. The resulting surge current can also damage the charged capacitor and the power  diodes themselves. However, without the diodes, the resulting >600A current spike destroys the microcontroller (IC2) and damages C6.

Even if true, the "Testing Capacitors Out of Circuit" section at the bottom of this web page explains the practical reasons why you still may need to desolder and test caps outside the circuit, which is the only way I test ESR with my DE-5000.

We were talking about "in circuit" testing and now you are talking about "out of circuit" testing. In that case the DE5000 is the best tool for the job. It even has a nice short test fixture the TL-21 like it's designed for out of circuit testing.

[lisafig]

My multimeter doesn't have the Relative delta mode, so how can I calculate the lead offset?

Connect the leads together and take a measurement. Then measure your capacitor and subtract the first measurement. Then convert the result to the ohms value (100mV per Ohm). It's easier than it sounds with practice but not as easy as the Bob Parker which automates this in software and a button press.

Thanks for this, Shock. It's doesn't sound complicated. Just to be sure. First I fix my multimeter to the ESR meter adapter and connect the 2 leads on it. Then I put the multimeter in the voltage mode. Then I make a contact between my 2 leads and read the voltage. Then I measure the capacitor with my leads. Then I subtract the voltage of the leads of the voltage of the capacitor. Then I convert 100mV to 1Ohm.  Then I am done. This is right?

[Shock]

Thanks for this, Shock. It's doesn't sound complicated. Just to be sure. First I fix my multimeter to the ESR meter adapter and connect the 2 leads on it. Then I put the multimeter in the voltage mode. Then I make a contact between my 2 leads and read the voltage. Then I measure the capacitor with my leads. Then I subtract the voltage of the leads of the voltage of the capacitor. Then I convert 100mV to 1Ohm.  Then I am done. This is right?

Sounds good to me. Here are some pros and cons by the way.

EVB Pros - Easy to source, doesn't require assembly, minimal setup time, easy to operate, adequate input protection for in circuit testing, reference chart on front of meter, clear and easy to read display.
EVB Cons - More expensive of the two, microcontroller closed source.

ESR Adapter Pros - Can handle sustained 240V on input, no microcontroller, 4 wire measurement if required, cheaper to build with lower parts count.
ESR Adapter Cons - Requires a DMM with Relative/Delta mode preferred, slightly less bench and user friendly, requires more leads, no reference chart on front of meter, DIY is more effort of course.

You might want to check if J_Diddy_B is prebuilding any more ESR Adapters before embarking on making your own. If you only own one multimeter or no additional ways to measure voltage and capacitance there is another scenario I'll warn you about, when testing you often will want to measure voltages and capacitance. Swapping leads back and forth to the ESR adapter will get a bit tiresome so it's best if you have a dedicated multimeter/voltmeter for it.

I'm not trying to deter you making your own electronics but when you DIY everything it's a large time cost. My Bob Parker meter was a kitset (most of the work done for me) and the labor cost alone of me assembling it far outweighed the purchase price. So what I'm saying is 65 euros for something like the EVB or the even the DE5000 in the long run is nothing, most people will waste money on far worse, and this is a tool that could last a lifetime (perhaps not the DE5000 hehe).

[lisafig]

Thanks a lo Shok for taking the time to clarify all of these points! (I updated the comparison spreadsheet which starts to look good [people: don't hesitate to correct/complete/update it!] https://docs.google.com/spreadsheets/d/1rPS_IGrx5Mb8YCJV1efvbXw0whv1zEn_HW98xHTFB1E )

I guess I'll try Jay_Diddy_B ESR Meter Adapter as it fit all criteria I'm looking for: it's protected, cheap, in-circuit and open source (which is important for me). (Kripton2035 is working on an updated version with a screen (instead of reading it through a voltmeter) but it's not ready yet).

It won't be that cheap since it will cost me some time and maybe burns some components before succeeding (with 5 boards [cf. below] one should be working!), but I'm excited to try (if I make it, everyone should be able to make it!). I might try first in smd, and if I fail, then in through-hole. I'll keep you updated.

you download [the gerber files] and them upload them to some pcb service like jlcpcb : https://jlcpcb.com/quote
and you get 5 boards for some 13€ delivered to france in some weeks.
for the components, any type can go.
also look at the original thread for this esr diy meter, https://www.eevblog.com/forum/projects/esr-meter-adapter-design-and-construction/
there are lots of talks about it, and also people that made a through-hole (no-smd) version that is more suited to beginners.

[kripton2035]

It won't be that cheap since it will cost me some time and maybe burns some components before succeeding (with 5 boards [cf. below] one should be working!), but I'm excited to try (if I make it, everyone should be able to make it!). I might try first in smd, and if I fail, then in through-hole. I'll keep you updated.

by the way, the actual gerber files makes a board that is 58 x 108 mm. if someone had time to make it less than 100mm, it would be way cheaper by jlcpcb at least because the 100x100 mm boards are dirt cheap by most pcb manufacturers. for 8 mm it falls into the "normal board" category...

[kripton2035]

Kripton2035 is working on an updated version with a screen (instead of reading it through a voltmeter) but it's not ready yet

don't rely too much on this one : it's not ready (already noticed) and more important, it is very tiny smd work. I want to install it in quite small box, where all will fit it seems for now, but it's a very small space: the jay_diddy board is reduced to 5 x 3 cm ! definitely not an option for beginners (or install it in a bigger box )

[lisafig]

if someone had time to make it less than 100mm, it would be way cheaper by jlcpcb at least because the 100x100 mm boards are dirt cheap by most pcb manufacturers. for 8 mm it falls into the "normal board" category...

That's good to know, thanks for mentioning that!

the jay_diddy board is reduced to 5 x 3 cm ! definitely not an option for beginners (or install it in a bigger box )

Does it implies the same work but on the other way: redesigning the gerber file to insert some spaces on it?


ps: I updated the informations gathered on this (long) thread about ESR here: https://docs.google.com/spreadsheets/d/1rPS_IGrx5Mb8YCJV1efvbXw0whv1zEn_HW98xHTFB1E

[Shock]

A couple of days ago I found and brought an original kitset Dick Smith MKII ESR meter (Bob Parker design) and got around to assembling it last night. So I have that and the Altronics version and a few others to play with now.

I went through a batch of old stock Nichicon caps I have, and all went well with no causalities. Dave shows his MKII in this video here at 5m25s. Would be nice if the newer kits were $20-30 cheaper but it's still great value considering how useful they are. He has different leads, mine came with probes. I can tell his leads are 25% shorter than mine when he zeros his meter.

I also own a Dick Smith LOPT/FBT tester (aka ring tester or high Q inductor tester), which was designed by Bob Parker as well. Anatek who do the Blue ESR meter make it now. I had the opportunity to buy both completed kits for $40 a few years back, they are quite hard to find and was a steal at that price. But the seller would not post them out, so somebody got a bargain, unless the seller had terrible soldering which would make for a fun afternoon.

[gespeland]

Hi, I'm new here.
I just bought a DER EE DE-5000 LCR meter and I have a couple of issues but I'm not sure if it's a design thing or I have a bad unit.

1. I can't hear the beep. There is a beep (or two) when you press a button. I can barely hear it if I put my ear up to the unit. Is this normal or is there a way to increase the volume. I hear beeps just fine from my other multi-meters.

2. IMHO, the back-light is very dim. Does anyone else think so? Again, I'm comparing it to the displays on my other meters.

Any and all helpful input is greatly appreciated.

[Shock]

Hi, I'm new here.
I just bought a DER EE DE-5000 LCR meter and I have a couple of issues but I'm not sure if it's a design thing or I have a bad unit.

1. I can't hear the beep. There is a beep (or two) when you press a button. I can barely hear it if I put my ear up to the unit. Is this normal or is there a way to increase the volume. I hear beeps just fine from my other multi-meters.

2. IMHO, the back-light is very dim. Does anyone else think so? Again, I'm comparing it to the displays on my other meters.

Any and all helpful input is greatly appreciated.

We have a repair section post a new thread there should you require further assistance.

The first thing to do is put brand new batteries in. Beeps and backlights are subjective so you might need to provide more details and a video or image. But start off by checking out the review videos and images posted of the DE-5000 online, youtube and google images are quite helpful to get a comparison.

[WhichEnt2]

It may be possible to make an additional protection plugin for de5000 using schematic from iet appnote.
https://www.ietlabs.com/pdf/application_notes/035043%20Charge%20Capacitor%20Protection.pdf
https://www.ietlabs.com/pdf/application_notes/7-Charged%20Capacitor%20Protection-Digibridge.pdf

[grumss]

Hi all,
I havnt seen it mentioned anywhere, but i have built up a set of leads with the protection diodes actually built into the leads..
I use these leads for general testing and then for high accuracy testing just plug in standard leads.

I used back to back 1n4005 diodes and they work well- but i think it may be better using ultra fast diodes due to their lower capacitance