Ring tester

[tony359]

Hi all,

I'd like to add a ring tester to my toolbox to test flybacks but also low frequency transformers if possible.

I found a few products online, some based on the "diodegonewild" design, others are different designs. Some are available to build DIY, others are not.

Any suggestions on a DIY one I could put together? Ideally something which would also be able to test low frequency transformers, that might be handy.

So far I found these two:

http://bobparker.net.au/Basic%20Digital%20Ringer/ (the posher version is only for sale)
https://oshwlab.com/michelemancini2/blue-ring-tester

Any other options and/or recommendations?

Cheers!
Tony

[stj]

Re: Ring tester

i built several dick-smith ones - they work well
also there is a digital one now from Dany-K that looks more flexable


https://danyk.cz/avr_ring2_en.html
https://www.youtube.com/watch?v=QBbEYYWiBI8
https://www.youtube.com/watch?v=E1dopmxph2A

[tony359]

Re: Ring tester

Danu-K is "diodegonewild" indeed

My only issue with that is that there is no gerber file available - unless I am mistaken? Sure, I could make my own but learning how to use KiCad is on my to do list

[stj]

Re: Ring tester

gerbil file?
lazy bastard!

he used stripboard,
if you want to make one you can generate your own board with kicad or Eaglecad.

personally i use the old eaglecad 7.x before it got screwed over and turned into a cloud based mess by AutoDesk.

i build the dick smith ones on stripboard btw - the circuits are not that large.

[tony359]

Re: Ring tester

ahaha touche'!

I have no problems getting a PCB design and just turning into a gerber file - I thought I had to create the whole board! But how do I do that? I don't see files to be downloaded. Am I being a lazy bastard again?

Dany-K's one is good but there are some available which can also measure low frequency ones. I think Bob's tester I linked above is also doing LF ones?

[redwire]

Re: Ring tester

I feel the EVB guy in Portugal is too expensive at 72€ (USD $77, CAD $105, AUD $120) incl. shipping.
I have never seen the firmware file allowing others to build the tester.
It has a 3.3V impulse, JET and comparator for high sensitivity, boost-converter to run off 2 AA batteries, auto power off.

Diodegonewild is basic and lowest cost, but is less sensitive. He needed a MCU with a few more pins for that.

So I've been working on my own ring tester until I got burned by shitty Aliexpress IC's and lost interest lol.
Testing on oddball magnetics, some huge tube audio OPT and chokes, and small SMPS transformers.
Can't get more than about 7 rings on small SMPS transformers and shorted turns brings that right down to 0-1 ring.

[stj]

Re: Ring tester

ahaha touche'!

I have no problems getting a PCB design and just turning into a gerber file - I thought I had to create the whole board! But how do I do that? I don't see files to be downloaded. Am I being a lazy bastard again?

Dany-K's one is good but there are some available which can also measure low frequency ones. I think Bob's tester I linked above is also doing LF ones?

you print the schematic - or put it on a second screen if you run several
then recreate the schematic in eagle/kicad
once you have the schematic in cad you can generate the board.
you set the basics - size & number of layers.
then put the parts where you want them and the software tries to work out the track layout

you can trick these cad programs into generating stripboard layouts too.
you say that the grid spacing is 2.54mm and it has 2 layers
then you tell it to favor horizontal tracks on the top and vertical tracks on the bottom.
then magic happens

[tony359]

Re: Ring tester

you print the schematic - or put it on a second screen if you run several
then recreate the schematic in eagle/kicad
once you have the schematic in cad you can generate the board.
you set the basics - size & number of layers.
then put the parts where you want them and the software tries to work out the track layout

Ah ok, that is what I mean with "learning how to use KiCad is on my to do list"

I know what you mean it's just not something I can invest this amount of time on now - hence I was looking for something ready because I am a "lazy bastard"

[redwire]

Re: Ring tester

Bob Parker's Blue2 Ring Tester cannot be built, we have no firmware or PCB/Gerbers.

Lately when I need a ring tester, I just breadboard it using an Arduino. But it struggles for computing power with its fat library code.
So I thought go to a SAMD21 M0 or write it in assembly language for the '328 or '328PB. I can't decide.

Dany-K ring tester 2 added a meh comparator and pretty small excitation pulse, I haven't yet tried it.
I can't see what the minimum ring frequency is, you'd need for testing big magnetics. The ATtiny24 source code needs a bit of translation I guess.

I had a 12V 10A mains transformer and detecting a shorted turn on it not easy. You need a good sized pulse like 5V I find.

[eccerr0r]

Re: Ring tester

hmm...tempting to design and build one in case my sencore dies ...
thinking it should be doable in a tiny2313... hmm!

(2313 because I still have a pile of unused at90s2313s that are waiting for a use ...)

[redwire]

Re: Ring tester

Tried out the circuit on a big ass choke, Hammond 193M rated 10H 300mA 63Ω weighing in at 10.5lbs/4.8kg.

You can see it rings for over 200msec which is a huge window. The comparator chatters a bit before and after. The spike is my S/W gate closing at the end (mosfet off). A 25msec gate dampens it fast and you get a wrong low ring count of ~8. Top blue trace is the comparator output, bottom yellow trace is output of the JFET.

I find you need more than a basic ring count because the magnetics being tested can have over 1,000,000:1 difference in inductance value. Then there is the effect of the shorted turns. uH matter for SMPS transformers and small inductors.


Shopping for an ARM MCU to get into and finish this.
ST are really expensive now and I hear their dev environment is brutal.
Microchip SAMD21 looks good but I can't find the dev board I have for it and the datasheet is at 1,153 pages.
ARM suck they've made everything super complicated.

It's a matter of a MCU for $1.50 or $6 I guess.
Open to any suggestions.

[stj]

Re: Ring tester

there are good st clones from gigadevice all over ali
you can use arduino ide with them

or you can use a raspberry pie thing, but i wouldnt recommend them - the i/o isnt 5v tollerent and they have no cpu cache.

or maybe an esp?
not much io on those but arduino ide supports them and they are piss-cheap
https://www.aliexpress.com/item/1005005470719229.html

[tony359]

Re: Ring tester

there are good st clones from gigadevice all over ali
you can use arduino ide with them

Thanks.
Could you share a link of one of them?

[CapLeaker]

Re: Ring tester

Redwire, you couldn’t find anything bigger than that? Lol

[redwire]

Re: Ring tester

I think a Ring Tester should work with big iron as well as small ferrites lol.
Still working on it, waiting for new parts.
------------------
I have learned there is no point being really cheap with MCU's even $1 more can get you tons of memory and features.
But three timers may not be enough for a better ring tester. More later.

For a bunch of magnetics I have, I prove things by adding a shorted turn and compare the before/after ring counts.
Large 12V 10A 60Hz transformer gives: 11 rings (primary) at 930Hz, shorted secondary (at center tap) 7-8 rings (primary) at 10kHz on the breadboard.
I thought some smarts should be added to the ring tester- so that is not misleading or a "pass".

From the Bob Parker instruction manual:
Low frequency transformers
"50/60Hz mains and tube output transformer primary windings produce much lower readings than ferrite cored transformers. If possible, always compare the tester's readings on a suspect transformer with its readings on a known good transformer of the same kind.
Typical readings are around 15 to 30 for a good transformer primary winding without any interference from other components in the circuit.
Shorted turns usually drop the reading to less than 10, however a solid short circuit on a secondary winding can produce a reading similar to a good transformer, so keep this in mind.
Please try out the tester on as many transformers and inductors as you can, to get a “feel” for what are normal readings. There are so many different inductors and transformers that it's not possible to provide “hard and fast” readings for all of them."
-------------------------------------------------------------------------

I was looking at the under $2 MCU offerings that are low power. The Blue Ring Tester has the 2xAA 3V->5V boost converter running all the time and powering the 5V MCU which goes to sleep. Bluepill STM32F103C8 is not low power enough in sleep mode.

Just tried Microchip MP LAB X IDE a 1GB download and install and what a piece of shit. It's covered in social media/cloud based crap and my firewall complained it wants LAN access. Then the message "you do not have a compiler installed" showed up Microchip is trying to railroad you into using their subscription compiler. Sigh. Need to install 2GB more... really?!
I love Atmel parts but Microchip buying them was a tragedy. Steve Sanghi is out to lunch. I can see why Arduino abandoned them now for Renesas.

Uninstall the IDE and it left shit stains all over - undeleted folders, files, registry entries and lots of time cleaning that mess up

Even Atmel Studio is a near 1GB download that Zuckerberg seems to have commissioned. Unbelievable.