Dragon's Lair Fans - Arcade Lifestyle
General Chat => Technical Area => Topic started by: level42 on April 28, 2011, 09:56:43 PM
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OK people.
We all know the story.
Many people in the hobby suggest replacing all caps in about all electronics we come across in our hobby. With good reasons of course. Electrolytic capacitors (often shortened as caps, or as we say in Holland Elko's) _CAN_ dry out over time and loose (partly) their function.
Yes, even I was always replacing caps like nuts on everything I came across. But as soon as my first cap-kits from a certain well known supplier arrived, I got some doubts.
The delivered Xicon caps felt extremely light and looked cheap. Of course, just like with everything, people will vary in opinion, but I've searched the internet, and generally Xicon is not considered as being a top brand cap maker.
Still, I have done several PCB's (like the one's in my SW cockpit) and others. Yes they work OK (mostly), but it didn't feel right somehow to take out the Nichicons (yes old, but one of the top cap brands) and replace them with the Xicons...
Also note that cap producers build various lines of products, each with their "target" use. Some are simply better than others.
So, the alternative was to shop at RSonline for good brand caps. Panasonic sounded trusty enough, and also Rubycon and Nichicon were available. I steered clear from the RS (own) brand for the same reasons as not wanting the Xicons.
Now.....I had made a list of caps that I was going to need to replace for my Asterock. Pretty soon (also because of minimum quantities you must order, like 5) I had reached an amount of almost 50 Euro's. Yes I selected all good quality brands and 105 degr. versions, but still that's a considerable amount of money.
Another factor. I've got a number of game PCB's, PSU's, and even monitors (f.i. the very old Sanyo in my Nintendo cab) that are still running the old caps and they simply look GREAT.
I've also done some measuring in the past around an original Atari Big Blue and there was virtually 0 ripple voltage over it, indicating it was still running fine....
Now...of course lots of these caps are 30 years old. So.....what I wanted is a quick and simple way to KNOW if I should replace a cap, or not.
A general DVM (or multi-meter as wel call it) is useless if it already HAS a capacitance tester. What this does is simply measure the capacitance, and even IF it gives (about) a good indication, that's not really that important and not an indication if an electrolytic capacitor is still OK. (Check capacitance values, they already have a 20% margin in their value from the factory !).
Now what we DO want to know is the ESR, or in other words the Serial resistance of the cap. Now you cannot measure this with a normal Ohms meter, because it's a cap....
Some time ago, there was a smart bloke from Australia (Bob Parker) who invented a cheap ESR meter that was affordable for everyone, but still very useful.
His name is Bob Parker. IIRC the meter was published by a magazine and thus a kit to be build. Later all kind of companies produced them in different ways: http://members.ozemail.com.au/~bobpar/esrmeter.htm
The principal is that a 100 kHz frequency is sent through the cap, and this signal is analyzed to know the ESR value.
Anyway, two versions of this meters were pretty interesting. One is from Russia:
http://www.radiodevices.ru/esr/esr4.htm
This one has some very good specs and I really like some features like the test socket on the device itself. It's also quite cheap.
However, they have had delivery problems of parts fort the past couple of months and I don't really want to wait any longer.
So.....I ordered this one:
http://www.peakelec.co.uk/acatalog/jz_esr70.html
(http://www.peakelec.co.uk/art/esr70-1.jpg)
This is readily available. There are even some Dutch distributors but one only delivers to companies and the other was simply more expensive than ordering directly at the manufacturer....
This one also has excellent specs and features and it looks very professionally built. One of the best features is that it discharges caps should they have any load left. This makes it not necessary to discharge them all before measuring which saves a lot of time.
Anyway, as soon as I receive it I will do some measuring on new and old caps and publish some results here.
I think this is a good investment that will earn itself back in a very short time.
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sounds cool, but can you use it on caps which are still in circuit?
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Yes indeed you can (in most cases) that's one of the big plusses ! :D
Here are the features as copied from the mentioned site:
Features
Measure capacitance and ESR.
New enhanced dynamic range of 0.00 to 40.0 ohms.
ESR Resolution as fine as 0.01 ohms!
Supports capacitors from 1uF to 22,000uF.
Capable of In-Circuit measurement of ESR.
Polarity free, connect any way round.
Protected against highly charged capacitors.
Great for low DC resistance checking too (such as PCB short checking).
Supplied complete with 2mm male test leads and 2mm compatible gold plated crocs.
Test leads are ultra-durable and 45cm (18") long with 2mm plugs.
Enhanced software compensation of cable resistance.
Complete with comprehensive user guide.
Capacitor reference table included.
Tests at the industry standard 100kHz.
Long life alkaline battery fitted.
Just 100mm x 70mm x 20mm
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Thanks for all the detailed info and the links, Andre. Very interesting indeed.
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Sounds like a cool device, and "in-cirquit measuring" is indeed a very big + !
the more simple variants are not capable of doing that, which is fine if you like to spend time soldering every cap out ;D
And indeed it will earn itself back if you need to "cap" alot, i mean your current list already reached 50€ so imagine if you only need to replace 3 caps instead of 20+ per project..
and im not even yet talking about the time you spend with replacing "working" caps..
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makes it extremely interesting. already looking forward to your test results, andré!
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F....... I just got a reply from Mike from Russia that they have a couple of their 4.0 in stock now....rats.....
Cancelling the Atlas right away....
Do note that the Russian doesn't have auto-discharging BUT it does have a much nicer price-tag at 75 DOLLARS (about 50 Euro's with current rate !!!) Delivered at your home world-wide....
RATS !! I was just an hour too impatient :evil: :evil: at myself.
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F....... I just got a reply from Mike from Russia that they have a couple of their 4.0 in stock now....rats.....
great news! i need to get one as well once it has successfully passed the L42QC (level 42 quality control)!
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I'm looking at capping my Rygar board (finally got one!) as it has developed a sound fault after about an hour of playing with it!
Will be very interested in your results.
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Mmm, well I guess everybody in the UK was having a holiday today, no reply to my cancellation e-mail. But I thought, what the hell, and also ordered the Russian version.
Still planning on canceling the ESR70 though, unless anybody wants to buy that one from me...
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Mmm, well I guess everybody in the UK was having a holiday today
yep, its a bank holiday on monday too,
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Will be very interested in your results.
Same for me 8)
Very interesting topic, André :)
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Mmm, well I guess everybody in the UK was having a holiday today
yep, its a bank holiday on monday too,
Damn.....so it was bank holiday last friday, or was everybody free for "the wedding"?
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or was everybody free for "the wedding"?
what wedding? ;) 8)
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Mmm, well I guess everybody in the UK was having a holiday today
yep, its a bank holiday on monday too,
Damn.....so it was bank holiday last friday, or was everybody free for "the wedding"?
it was a special bank holiday so people could celebrate the wedding, most people were off work
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Indeed, and yesterday I got a confirmation from both the UK (Peak Atlas version) and Russia that the units have been sent ...... :S
I had sent an e-mail only an hour or so to Peak to cancel the order but due to the holidays they missed it...
I'll have to send it back to them to get a refund....O well...my mistake for being impatient. And the difference in price between the Russian and UK unit is still big enough to send it back....
A bit of a shame, it would have been fun to do a 1:1 compare between the two and write a "review"....
But I'll have to send it back unopened.
That is, unless someone wants to buy the Peak Atlas version from me ? ;)
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A bit of a shame, it would have been fun to do a 1:1 compare between the two and write a "review"....
But I'll have to send it back unopened.
unopened? the box or the package the thing is in? i'd try opening it up carefully, test it and put it back in - that's what i often do :P
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Mmm, don't want to take any risks. I want the over 100 Euro back.... ;)
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That ESR meter is nice because of the possibility to measure ESR without the need to remove the caps. Being a little too expensive for me (more than 100 euros if you add taxes and shipping costs) i bought a little circuit that allows the measure of the loss current from the caps. attached is the scheme (taken from http://www.microst.it/tutorial/cond_elettro_4.htm (http://www.microst.it/tutorial/cond_elettro_4.htm))
Pros:
- it's very cheap and easy to build up
- it tests the cap under voltage (an "actual" condition)
Cons:
- you need a voltage generator able to work close to the working voltage of the cap
- it works out of the circuit
It works for me (even if, i must say, that i use that circuit only to check used but recent caps to see if they have losses: if they are 20+ years old i replace them anyway ;))
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The Russian one is only about 50 Euro's (75 US dollars to be precise, so it depends a bit on the exchange rate) INCLUDING world-wide shipping. That's the great thing that you pay it in dollars, makes it WAY much cheaper for us ;)
Really think the ease of it is worth that amount. Although your set-up may work (still doubt it gives the same results as a micro-proccesor controlled 100 kHz frequency check) it does seem to be a bit clumsy...
Still waiting for both units by the way. Hadn't expected the Russion one arrive yet, but the UK one could have made it. I figure I'll receive that one on tuesday.
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Yea, i am curios to see how do they work. I also read on the net the ESR measure is not suffcient to determine a cap is good or not: please, when you will have them, try a measurement on a surely bad cap and report the ESR ;D
The idea i have on those little bastards is that one measure (ESR or loss current or capacity with a cap meter) is not sufficient, but all the three should be taken toghether ;)
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I also read on the net the ESR measure is not suffcient to determine a cap is good or not:
Got a link, I'd like to read that.
Actually, I think most caps I've replaced so far were either not totally bad....except for the "fold-over" cap on the Sanyo in my Nintendo cab....but I don't think I've got that one still here ;)
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The Russian one is only about 50 Euro's (75 US dollars to be precise, so it depends a bit on the exchange rate) INCLUDING world-wide shipping. That's the great thing that you pay it in dollars, makes it WAY much cheaper for us ;)
Really think the ease of it is worth that amount. Although your set-up may work (still doubt it gives the same results as a micro-proccesor controlled 100 kHz frequency check) it does seem to be a bit clumsy...
Still waiting for both units by the way. Hadn't expected the Russion one arrive yet, but the UK one could have made it. I figure I'll receive that one on tuesday.
We've had so many bank holidays recently the post is taking ages
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The UK one is waiting at the post office for me since two days...but as mentioned I'll simply refuse it so it will be sent back :)
The Russia one they tried to deliver yesterday but no-one was home and they'll try again today, obviously at least they want a signature....I do hope that doesn't mean I'll need to pay import duties, I totally forgot to ask about that....:(
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The Russian one has arrived !
No added taxes luckily!
First quick impressions: looks professional, excellent quality test-leads, very light-weight (due to button-cell batteries).
Did some first test runs on the caps I had removed from the G05-802 in my Asterock and on some brand new caps from a Bob Roberts kit.
Some surprising (well actually not really) results but I will post a video and some extensive measuring reports ASAP (could be sunday though ;))
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I will post a video and some extensive measuring reports ASAP (could be sunday though ;))
Great, thanks for that André!
I'm sure after watching this I will simply jump of my chair and say out loud "I know caps measuring", matrix style.
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[OT]
Andrè, up to my head i dont remember which is, and the capacitance value, of the cap in Sanyo monitors that cause foldover... (i am going to order some good cap from RS and i wanna insert a spare couple of those caps for my monitors)
ANSWER TO SELF: C407, 10uF 160V ;D
[/OT]
What is the situation with your testing? :spaceace:
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Sorry, somehow I didn't see your posting Bari....
Indeed C407 or C408 on the really old Sanyo's.
I did some testing on an AR-2 board with some interesting results and I also compared an OLD and a NEW Big Blue and also these results are interesting...
Hope to make the video tonight !!
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now i am curious too :)
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heheheh......Building up the tension ;)
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just sent an order to RS online for an ESR70... curiosity went me crazy :D
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What ? Why didn't you order the Russian one ?? Would have saved you a lot of cash plus....and I think it's better...
Sorry, I have made some videos before but turned out I talk TOO much ;) It is also VERY hard to do sample measurements while holding the camera showing the result. I need a stand but don't have one...
I'll be doing of combo of text, pics and some videos because else the vids become too long.
Anyway. The short answer to: do I need this ? Yes !
Of course, you can go about and replace every cap you find around. That will also work of course. But if you're curious like me and don't believe the "howling wolves" just because they "howl", or if you don't believe every old cap is bad just because it's old and want to save time & money then this shouldn't fail in your tool bag....
I will open a new thread about this meter in the Technical Area.
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What ? Why didn't you order the Russian one ?? Would have saved you a lot of cash plus....and I think it's better...
i bought it because i was going to order some caps from RS and they had only the UK one available... i could not resist :D
In addition, i was almost sure you had sent the ESR70 back, so we could make some cross tests if needed... didnt you?
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Yeah I sent it back, and I hope they will give me back my money.... :-\
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Yeah I sent it back, and I hope they will give me back my money.... :-\
Any news on this?
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I saw it "live in action" yesterday :P