ESR meter circuit  - Page 1
Forum section: electronics / beginners

author: M0BSW
author_rank: Frequent Contributor
timestamp: September 13, 2012, 06:30:50 pm
content: Hello Group,Does anyone have any idea where I could get a circuit diagram for a ESR meter a good one, there are alot of things I like building myself and this piece of test gear is one, looking for a winter project.Paul

author: firewalker
author_rank: Super Contributor
timestamp: September 13, 2012, 07:38:50 pm
content: Just perform a search (on this forum) with the keywords "ESR meter".Alexander.

author: robrenz
author_rank: Super Contributor
timestamp: September 14, 2012, 12:04:27 am
content: Make sure you are at the top level of the forum when you do a search.

author: FenderBender
author_rank: Super Contributor
timestamp: September 14, 2012, 12:08:46 am
content: The Bob Park ESR Meter kit has been around for a few years. I wouldn't even play around with trying to use someone else's schematic. Just get the kit. Save you some hassle.

author: EEVblog
author_rank: Unknown
timestamp: September 14, 2012, 12:12:40 am
content: http://members.ozemail.com.au/~bobpar/k7214.pdfDave.

author: mariush
author_rank: Super Contributor
timestamp: September 14, 2012, 02:21:07 am
content: This site has a bunch of esr meter projects :http://kripton2035.free.fr/esr-repository.htmlanother page full of links to esr projects :http://www.emil.matei.ro/links2.phpHere's a bunch of links I have bookmarked about ESR meters and theory (unsorted, use Google Translate if needed):http://koti.mbnet.fi/hsahko/elek/kv/esr/index.en.shtmlhttp://www.qsl.net/iz7ath/web/02_brew/15_lab/06_esr/index.htmhttp://members.shaw.ca/swstuff/esrmeter.htmlhttp://kakopa.com/ESR_meter/http://members.ozemail.com.au/~bobpar/esrhints.htmhttp://forum.audiofil.ro/index.php?topic=1160.0http://vrtp.ru/index.php?act=categories&CODE=article&article=2484http://kripton2035.free.fr/commercial%20esr/esr-elektorsept2.htmlhttps://www.eevblog.com/forum/product-reviews-photos-and-discussion/esr-meter-teardown-hungarian-cottage-industry-unit-from-ebay/msg90432/?topicseen#msg90432http://kripton2035.free.fr/digital%20esr/esr-go-russian.htmlhttp://vrtp.ru/index.php?showtopic=19662&st=0http://www.electronicslab.ph/forum/index.php/topic,8863.msg255480.html#msg25548http://kaspars.id.lv/?menu_id=32

author: M0BSW
author_rank: Frequent Contributor
timestamp: September 14, 2012, 03:08:07 am
content: thanks again everyone , what really helpfull bunch you are, plenty to look at.cheersPaul M0BSW

author: FenderBender
author_rank: Super Contributor
timestamp: September 14, 2012, 09:06:34 pm
content: Quote from: EEVblog on September 14, 2012, 12:12:40 amBeware that Z86 chip is a microcontroller. Code isn't available as far as I'm concerned.

author: PA4TIM
author_rank: Super Contributor
timestamp: September 14, 2012, 11:03:17 pm
content: http://www.pa4tim.nl/?p=1728This is my version. Checked it agains VNA and bridgemeasurements.Remember, ESR is frequency dependend and at a minimum at SRF. All measured values only are usefull if you know the ESR specified by the manufacturer at the frequency he specified.A better rating is D, the dissipation factor. That tells you the ratio between R and Xc. An ESR of 1000 ohm is very good for a 100 pF at 1KHz but 0.01 Ohm lousy for a 10000 uF cap at 1 KHz.The first one has a D of 0.000628 so 0.062% of the power is dissipated in the ESRThe second one has a D of 0.628 so almost 63% of the power is dissipated in the ESR of the cap.But that 10000 uF at 100Hz and an ESR of 0.01 ohm has a D of 0.0628 and only 6.3% is dissipated.But most meters like the peak ect measure at 100 or 200KHz. A 10000 uF cap is probably an inductor at those frequency, besides that Xc is 0.000159 Ohm at 100KHz and if the factory gives the specs for 100 Hz you still know swat about this cap. An other good parameter is loss angle but it must be measured vectorial. Good LCR meters use it ( besides D)Only thing you know that if its real high, the cap is bad. But a scope meaurement would have told you too. I use it if the instrument is a) so bad it can not be powered up or it is not used for long so I have to reform the caps. After reforming i meaure capacitance and D. ( or if I'm lazy i use my esr meter but most times I use a bridge and measure D, or a vna and measure loss angle)These things happen to caps:Loss of capacity,DC leakage,High ESR.In real live the first one is very common in smpsThe scond in high voltage circuits (also primary SMPS)The third is not as common as everybody thinks, most just believe those meters to much and do not understand ESR.All three can come together or appart.3 other failures are electrode rupture ( sometimes intermittend) or called an open cap.Intermittend ESR ( i have found some using my analog ESR meter while bridges and VNAs did not noticed it,Dielectric absorbtion.( more as normal)From a repair in a dvd/HD player I replaced 34 bad caps. 2 had high ESR.Just fixed a selfinduction bridge, 1 high D cap and one with degraded 10 nF instead of 100 uF capacitance but perfect ESR.So an ESR meter is handy when used wise ( and replacing a cap that was not bad after all will do no harm so everybody is pleased and loves their ESR meter.)this is what ESR looks like over a frequency sweep using RF-IV measurement on a analog VNA

author: M0BSW
author_rank: Frequent Contributor
timestamp: September 15, 2012, 07:55:57 am
content: Wow that was a good lesson ,I'm taking it all in you know like a sponge. Also if no one minds i'm printinting this help I get for future reference, all your advice is priceless & helping me no endThank you for your time.Paul

author: AndyC_772
author_rank: Super Contributor
timestamp: September 15, 2012, 08:52:34 am
content: Quote from: PA4TIM on September 14, 2012, 11:03:17 pmCould you tell me more about the instrument you used to obtain that plot? It looks like a fantastic piece of kit and I want one for my lab!

author: mianchen
author_rank: Regular Contributor
timestamp: September 15, 2012, 08:56:28 am
content: Quote from: AndyC_772 on September 15, 2012, 08:52:34 amI want one too but don't think I can afford it with my hobbyist level budget

author: M0BSW
author_rank: Frequent Contributor
timestamp: September 15, 2012, 09:30:36 am
content: I was afraid to ask, looks expensive

author: Rerouter
author_rank: Super Contributor
timestamp: September 15, 2012, 09:59:32 am
content: it almost looks like the impedence is done via a ramped sine wave source fed in and measuring the respective voltage produced across a known low parasitics resistor to get an impednece voltage (and somehow linearly rectify it) e.g using it as a filter, and likely with a sync output for the start of the ramphowever the frequencies involved interest me, as 30Mhz there makes me think it it caps out at 100-140Mhz, no easy task to make a glich free sinewave at those frequencies,its the phase measurement that has me purplexed though, though i suppose it could be done with a differential probe, measuring against the impednece resistor and the signal fed in, or some RF black magic to have discrete elements bring that back to a DC voltage that can be easily measuredwhile the device may be quite expensive i dont believe it would be out of the scope of the average guy to jerry rig a much lower accuracy one, or for the rf guys to go nuts and release a design that can pull the same off for sub $100,

author: PA4TIM
author_rank: Super Contributor
timestamp: September 15, 2012, 11:15:45 am
content: I did not expect the picture to be such a riddleThis instrument is a Vector network analyser (VNA), an old HP to be precice. Nomally a VNA is not able to make a sweep like this with this precision because it is made for measuring around 50 Ohm.Better suited is a RF-IV meter. But with the use of a jig I made and a modified Tektronix inline current probe i made this setup. This was just an experiment to show you can do RF-IV with a classic build VNA that has a test and reference receiver. More modern ones with internal generator-reference connection can not do this "trick". This vna has a highest resolution of 0.25 dBSweep here is 100MHz, so 10MHz/div.I have a digital VNA that has also a RF-IV option. That makes meauring this a lot more easy because it does all the math and instead of giving dB/div it displays |Z| direct. But I made some custom traces for that so it is also able to measure ESR doing a S21 sweep. This because that gives more accurate resolution as using S11 reflection measurement.The digital one is a VNWA from SDR-Kits ( lots of info about that one on my site, got two of those, one with a test set that let me do SP2 sweeps, the other has a Rf-IV board and expantionboard so it makes S11 and S21 meaurements in one sweep ) the first one i build my self, the second was a gift from Tom, the vnwa designer. You can buy them around 500 euro.The old HP costed 20 euro for the non complete base unit, 80 euro for a second one that did not worked but had the display unit. 100 euro for the non-working 8601 sweepgenerator that was made for this VNA. The VNA is a 8407 ( or 8704 alway mix the numbers)There is a budget way to do RF-IV meaurement. Google for 3 voltmeter methode.Also interesting lecture is the Agilent impedance handbook, free for download from Agilent.

author: M0BSW
author_rank: Frequent Contributor
timestamp: September 15, 2012, 11:41:14 am
content: Now I'm getting into the deeper side of electronics I find all this very interesting and a little confusing at the same time, some of my Radio amateur freinds are wondering why I spend more time burried in books rather than working DX. I really enjoy all this and I think it will make me a more rounded Radio Amateur as a result, thank you for the explanation.Paul M0BSW

author: toli
author_rank: Frequent Contributor
timestamp: October 01, 2012, 07:18:59 pm
content: Sorry for bumping up this thread after a couple of weeks, but I came across something that might be interesting.I found this on DX:http://dx.com/p/100khz-1-7-lcd-auto-ranging-esr-capacitance-meter-black-1-x-6f22-157241The specs (range/frequency/buttons/battery type/table of values on the front panel) seems very similar to the Bob Parker design, doesn't it? For 60$ its not too expensive either, and I'm sure it can be found cheaper on eBay/some other website. Anyone interested in checking that out for the rest of the forum members?

author: kripton2035
author_rank: Super Contributor
timestamp: October 01, 2012, 07:54:51 pm
content: pictures of it with more details ...http://www.mib-instruments.com/servlet/the-2854/MESR-dsh-100-AutoRanging-In-Circuit/Detail

author: Smokey
author_rank: Super Contributor
timestamp: October 01, 2012, 09:30:14 pm
content: MiB eh? Does it get delivered by Will Smith or Tommy Lee Jones? If you do a tear down, do you get neuralyzed?These things are probably just run by a microcontroller. I wonder why they never have different frequency settings.

author: mianchen
author_rank: Regular Contributor
timestamp: October 02, 2012, 07:47:12 am
content: Quote from: mariush on September 14, 2012, 02:21:07 amI've built one on a proto board using the schematic in this link (http://members.shaw.ca/swstuff/esrmeter.html). Pretty easy and I have 'calibrated' it with some low value resistors. Now it has helped me identify 2 dead caps so far. One of them has >75ohms ESRThe uA meter is the most expensive component (£7)...

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: October 02, 2012, 09:19:04 am
content: Quote from: M0BSW on September 13, 2012, 06:30:50 pmThe September 2012 issue of Amateur Radio features an ESR meter by Jim Tregallas.Kits available from Aztronics in Adelaide ($69.95) or you can buy the PC board for $10 fromwww.users.on.net/~endsoddsAlthough the circuit is simple enough not to need a PC board (it's 2 x ICs plus a few transistors).A brief construction report by another constructor appears in this month's issue of the magazine.

author: M0BSW
author_rank: Frequent Contributor
timestamp: October 02, 2012, 04:38:11 pm
content: Thank you I'll take a look:)