ESR meter with Arduino

Hi,

I'm about to build this project with parts I have and am a bit lost with caps that are being used.

I have a 2A104J greencap to use as the 100uf (C2).

But the 47uf, Bipol (C1) I do not have, only in electrolytic cap form. I am assuming that I need to find a bidirectional cap? is that what you call a cap that can be used either polarity?

I am finding it hard to find an assorted pack of caps which are not electrolytic on ebay.

Also the only transistors I have are BC328 and BC338. The schematic says 327 and 337...Is there a difference?

One more Q, how the hell are all of you guys making your own circuit boards?

Thank you.

I think that I am worndering how to wire up the push button ZERO with my 2 wire LCD display.

Hi,

I also built a standalone version of this and it seems to be working ok. There is one thing I don't know what to make of, though.

In the original schematic, there's R4 connected to Arduino digital pin 8. This doesn't seem to be used in any version of the code I found. From what I understand, this was intended to be used as a low current pulse output. Is this correct? If so, isn't the version posted by mikanb http://forum.arduino.cc/index.php?topic=80357.msg1210134#msg1210134.

So let me recap (absolutely no pun what-so-ever intended!):

  • The original R4/D8 connection was never used by any version of code seen here on this thread.
  • The 1k-PNP-1k implementation by mikanb does what R4/D8 originally intended to do but never did.
  • The ak-PNP-1k implementation by mikanb is superior to the original R4/D8 implementation, because it adds a bit more decoupling from the MCU through the PNP.
  • In a revised design, I could omit the R4/D8 connection in favour of mikanb's implementation.

Right...? Is it?

Cheers,

Ali

@alibenpeng right it is! your observations regarding R4/D8 are correct :-)

szmeu

Thanks for clearing this up!

Cheers,

Ali

I'm looking for SMD parts for this, but being pretty noobish I'm not sure what characteristic to look for in the 1N5822 schottky diodes - could anyone help me explain this? The discussion have been about 300mV voltage drop, but I don't understand what characteristics of the diode this comes from. The specified forward voltage drop on the 1N5822 I've found is 525mV or 950mV.

Great ! Thanks for share !

Thanks for your share !

Hello!

I got messed up reading this whole posts... Not perfect in english, sorry.

Can anybody tell me - or post- the correct code for this project? I really would like to give it a try, but don't know what changes on the original code I have to make. And where...

Help would be nice!

Thanks! Andy

IT would be nice to have A complete circuit schematic and code pack. I know there have been alot of changes since the very first post. This is a great project just unorganized. Would someone be willing to bundle all the latest up and put it in a zip file to download.

yeep, it would be so cool...

jtroutt19: IT would be nice to have A complete circuit schematic and code pack. I know there have been alot of changes since the very first post. This is a great project just unorganized. Would someone be willing to bundle all the latest up and put it in a zip file to download.

Agree!

Baravantan: ... 10 downloads of the attached .zip file with code, images, schematics and PCB design...

Great ! Thanks for your share !

Help please, does anyone have arduino code for the original schematics? thanks

hi dear
please tell me,DUT connect to the wich pins of CN1?

This is very old thread, however I have a need to build some simple, cheap and more or less reliable ESR tester fast…

I have look and read this thread and dr. Le Hung website about ESR. Few things I have noticed:

  1. The schematic is almost identical to dr. Le Hung ESR part.
  2. Notification on this forum ESR is not able to do in-circuit measurement, while dr. Le Hung device is.
  3. Dr. Le Hung do not expose source (hex only for ATmega88PA) as it sold the device.
  4. The 47uF discharge capacitor need to be non-polarized? This is not commonly available part easily found in local stores.

Upper force me to believe many things could be improved for this Arduino open source version.

  1. If hardware is almost identical, identical features this ESR tester should have. I.e in-circuit measurements (up to ~300mV test voltage) is possible to achieve.

  2. As I’m only amateur, my knowledge in electronic is limited. However, if 47uF is jut discharge capacitor, I believe it could be used two 100uF 100V in series el. capacitors (with the diodes protection) - the circuit to make non-polarized capacitor from two polarized. This kind of capacitor configuration double its own ESR, however if it serves only to discharge it before test, this is not crucial. Even better, any, especially larger capacitors should be discharged before test in order to protect MCU.

  3. The most important feature for an ESR is to have measures with at least two freq. I have not found at dr. Le Hung documentation that his device can do that as well (only measurement at 100KHz).

Anyone with more experience can elaborate about for this circuit?

If not, is there some DIY circuit with commonly available parts is proven to be able for in-circuit measurements as well as can test in at least two freq.?

Thanks in advance.

(deleted)

CAPESRFREQ.ino (19.1 KB)

I improved the ESR measurement, added Capacitance measurement to the ESR measurement, and combined the code with an L-C-R meter. The meter was described in our radio club magazine: https://www.pi4raz.nl/razzies/razzies201904.pfd (Meter description is also in English).

PA3CNO: I improved the ESR measurement, added Capacitance measurement to the ESR measurement, and combined the code with an L-C-R meter. The meter was described in our radio club magazine: https://www.pi4raz.nl/razzies/razzies201904.pfd (Meter description is also in English).

Where I can find code and schematic for that? Tnx

@PA3CNO
I looked at your design, after i changed your url to end in PDF…and not pfd

I was looking for a design where the voltage was max 100mV, so you would be able to test in circuit.
I see you have changed the schottky design, to the opposite… bugger

/J