Author Topic: Other equipment for testing I should look for  (Read 11547 times)

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Offline PA4TIM

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Re: Other equipment for testing I should look for
« Reply #25 on: March 20, 2013, 12:18:37 am »
Datasheet gives Z, ESR meters can meaure everything from crap to ESR. Use D or measure Z at 100 KHz like most panasonics state.

I have done lots of tests on reforming caps ( hundereds) and the change in other parameters. 30 year not used caps, good ESR, good D, capacitance within specs but to much DC leakage. After reforming DC leakage Good, capaitance the same, sometimes a bit lower, sometimes a bit higher but this is not significant.
ESR change was also not significant.
I build several reformers. Shelflive from old caps is much longer, the modern caps I have are 1  to  7 years old, never have to reform one, leakage was like new.

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Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #26 on: March 20, 2013, 12:49:13 am »
Datasheet gives Z, ESR meters can meaure everything from crap to ESR. Use D or measure Z at 100 KHz like most panasonics state.

I have done lots of tests on reforming caps ( hundereds) and the change in other parameters. 30 year not used caps, good ESR, good D, capacitance within specs but to much DC leakage. After reforming DC leakage Good, capaitance the same, sometimes a bit lower, sometimes a bit higher but this is not significant.
ESR change was also not significant.
I build several reformers. Shelflive from old caps is much longer, the modern caps I have are 1  to  7 years old, never have to reform one, leakage was like new.

That's great info.  A lot more experience than I have.  Would you be willing to share your design for the reformer?  I'd still like to build one.  Also what brand of caps would you say has the best non-use stability?
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Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #27 on: March 20, 2013, 01:04:06 am »
... measure Z at 100 KHz like most panasonics state.

My LCR meter only goes up to 10Khz.  Only other thing I have is an ancient impedance bridge which I could use with my function generator.  I'm trying to learn more about and focus on analog stuff, hoping to work my way up to higher frequency analog.  What can you recommend in the way of essential impedance/capacitance/inductance measuring gear?
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Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #28 on: March 20, 2013, 01:43:05 am »
Don't want to hijack the OP's thread, but one more quick question: if it wasn't the shelf life, what else could have caused a new cap to have higher ESR?

Here is the series of events for me: I recently moved.  After setting up my lab in one of the spare bedrooms of my new place, I got sick of never being able to find anything.  So I built a database of all my components with fields for every possible useful parameter plus picture and datasheet and location (like which drawer it was in).

As I was adding entries, this involved DL'ing the datasheet and reading from it.  When I was adding a kit of capcitors I purchased from digikey, I came across the shelf life at temperature data.  Then I realised I had a problem, which then led me to add some derived fields which would tell me when an electrolytic cap was coming to the end of its shelflife (and for any other component I might have which also has a shelf life).

Then I did the next logical thing which was to grab the oldest binder of capacitors and test one.  This is when I came across a cap (first one out of the binder actually) whose ESR tested quite high.  I will admit that I never tested that cap before for anything (well, I'd be surprised if anyone would have either).

So, that experience and the data sheet is the source of my deciding that I'd reform any caps about to exceed their shelf life (and of course keep measurements as I do this to determine if this is effective vs doing nothing and possibly only reforming when about to put into a circuit, which seems anoying to have to wait for).

What is the best policy here?  I can certainly conceive of wanting to use these old caps to put into a circuit I'd want to sell.  Just only use new stock for this, or the other end of the scale and not bother worrying about electrolytic caps and how old they were?  What about just wanting to throw a circiit together but don't want to have the extra variable of a potentially bad cap causing undesigned behaviour?
« Last Edit: March 20, 2013, 01:45:14 am by madshaman »
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Offline PA4TIM

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Re: Other equipment for testing I should look for
« Reply #29 on: March 20, 2013, 08:00:21 am »
http://www.pa4tim.nl/?p=3775 about ESR
If you then use the find function on my site you also find pages about measuring  DC leakage ( and reforming caps including a schematic for a reformer/ leakage tester and simple ways with a bench supply.
If you want to learn more about impedance, i have a network analysis tutorial there too ( 8 downloadable pdfs) it is written for vna users but it are the basics in NA. A good start is the free Agilent download of their impedance measurement handbook ( but for network analyses you need a good understanding of electronic basics and complex notation, NA is not about measuring antennas and filters like many people think ( and it is most used for by amateurs, but it is for most about component behaviour on and off pcb)

The ESR goes exponential from infinity at 0 Hz to a lower value around 10-20 kHz, then it decreases further to a minimum, for big caps between 50 and 150 kHz, after that dip it increases again due to skinloss and dielectric loss. ESR is not a very usefull value on its own. For instance the ESR of ceramics caps is low, but the ESR of a good 100 pF cap can be over 1000 Ohm.
If you measure 2 Ohm at 10 kHz, this can be low or very high. This depends on the value of Xc and so C. If you have a good LCR meter it gives you D, this tells about the quality of the cap, regardless of other things. D is specified in datasheets, but D is given for a frequency. The standard is 1 KHz and 120/100 Hz. A D of 0.01 at 1 KHz, will be around 0.1 at 10 kHz because ESR decreases little but reactance decreases 10X. But that is all in the link. There are also pages about measurements on known bad caps that I found donig a repair. I measured them in several ways to compare.

Best LCR meters are bridges, alltough modern on cirrus chipset based ones come close. ( i mean affortable LCR meters, real good digital LCR meters have been around much longer but very expensive) I have a bunch of bridges, restored most of them and kne how to use them, mail me if you want to learn how to use it, But tell me the brand-type brigde you have and if rather unkown a sharp picture of the front. The fact it needs a seperate oscillator (and detector? )makes me think it will be a good one, Wayn Kerr, General Radio or ESI perhaps ?
On the site of Conrad Hoffman, also a member here if I'm correct, there is a lot of information about bridges too.



www.pa4tim.nl my collection measurement gear and experiments Also lots of info about network analyse
www.schneiderelectronicsrepair.nl  repair of test and calibration equipment
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Offline blewisjr

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Other equipment for testing I should look for
« Reply #30 on: March 20, 2013, 11:31:12 am »
Ok so two power supplies got it.  I think I will pick up two of those vellemans as I do not really know any brands and the agilents are very pricy.
 

Offline mzzj

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Re: Other equipment for testing I should look for
« Reply #31 on: March 20, 2013, 12:01:09 pm »

 Also what brand of caps would you say has the best non-use stability?

Avoid ultra-ultralow esr type electrolytics for general purpose use. 

Rumour is that these use water-based electrolyte that is more prone to electrolysis and  pressure buildup. One tell-tale to avoid water-based electrolytic caps is to look for temperature rating: -55 Cel rated cap is probably organic electrolyte, -40cel rated  caps are possibly water based ones.

I have plenty of old stock but when I have to order new electrolytics these are my fafourites:
Panasonic FC
Nichicon PW
United Chemi-Con LXY or LXZ
Rubycon (can't remember models)

I have same experiences as PA4TIM: ESR increase is hardly a problem in storage, DC leakage is the first sign of trouble.
And you can always cut one or two caps in half to see how much electrolyte there is left.

"Modern" ultralow esr types may show increased leakage already after 1 year in storage.  If the leakage current does not drop below spec even after reforming you better throw that batch of caps away!

Most of the major electrolytic capacitor manufacturers were having lots of trouble couple of years ago with ultralow esr caps.
Nichicon HM and HN series, United Chemi-Con KZE and various others. And Chinese "brands" are more or less trouble all the time.
 

Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #32 on: March 21, 2013, 05:15:54 pm »
http://www.pa4tim.nl/?p=3775 about ESR
If you then use the find function on my site you also find pages about measuring  DC leakage ( and reforming caps including a schematic for a reformer/ leakage tester and simple ways with a bench supply.

This is awesome stuff!  Thank you!  Thanks also for providing such a good response, appreciated.

If you want to learn more about impedance, i have a network analysis tutorial there too ( 8 downloadable pdfs) it is written for vna users but it are the basics in NA. A good start is the free Agilent download of their impedance measurement handbook ( but for network analyses you need a good understanding of electronic basics and complex notation, NA is not about measuring antennas and filters like many people think ( and it is most used for by amateurs, but it is for most about component behaviour on and off pcb)

You've got me interested enough to learn all about NA; will read your tutorials.  Thanks for the pointers to the Agilent handbook too!

Best LCR meters are bridges, alltough modern on cirrus chipset based ones come close. ( i mean affortable LCR meters, real good digital LCR meters have been around much longer but very expensive) I have a bunch of bridges, restored most of them and kne how to use them, mail me if you want to learn how to use it, But tell me the brand-type brigde you have and if rather unkown a sharp picture of the front. The fact it needs a seperate oscillator (and detector? )makes me think it will be a good one, Wayn Kerr, General Radio or ESI perhaps ?
On the site of Conrad Hoffman, also a member here if I'm correct, there is a lot of information about bridges too.

I'd definitely be interested in this, my bridge is a General Radio 1650A, For signal generation, I'm not so well equipped (yet), I have an HP3314A function generator and an old Wavetek function generator.  I'll send you an email soon.

Thanks again for the help, having someone point you in the right directions is half the battle.
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Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #33 on: March 21, 2013, 05:25:34 pm »

 Also what brand of caps would you say has the best non-use stability?

Avoid ultra-ultralow esr type electrolytics for general purpose use. 

Rumour is that these use water-based electrolyte that is more prone to electrolysis and  pressure buildup. One tell-tale to avoid water-based electrolytic caps is to look for temperature rating: -55 Cel rated cap is probably organic electrolyte, -40cel rated  caps are possibly water based ones.

I have plenty of old stock but when I have to order new electrolytics these are my fafourites:
Panasonic FC
Nichicon PW
United Chemi-Con LXY or LXZ
Rubycon (can't remember models)

I have same experiences as PA4TIM: ESR increase is hardly a problem in storage, DC leakage is the first sign of trouble.
And you can always cut one or two caps in half to see how much electrolyte there is left.

"Modern" ultralow esr types may show increased leakage already after 1 year in storage.  If the leakage current does not drop below spec even after reforming you better throw that batch of caps away!

Most of the major electrolytic capacitor manufacturers were having lots of trouble couple of years ago with ultralow esr caps.
Nichicon HM and HN series, United Chemi-Con KZE and various others. And Chinese "brands" are more or less trouble all the time.

Very very good info, thanks!  I never would have known ultralow esr caps had these issues, from what you've said seems best to avoid them if possible.
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Offline JuiceKing

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Re: Other equipment for testing I should look for
« Reply #34 on: March 21, 2013, 06:17:37 pm »
If you are experimenting and learning analog electronics, a good function generator is really helpful and certainly, after a scope, meter, and DC power supply my most frequently used piece test equipment. Avoid ones with high distortion (>0.1% THD) so that you have clean signals to test with.

Get LOTS of banana plug cables along with a variety of alligator and other smaller clips that go on the end of banana plugs. Use them ALL the time. I standardize on the 3-foot ones and have a set of 10 hanging on the bench.

Also, get some good quality BNC-terminated cables and various T-connectors, terminators, and adapters for banana connections. I started with cheap BNC cables but eventually upgraded to Pomona because they make much more reliable connections and also have better high frequency response.

If you breadboard, a most useful thing is a small collection of linear potentiometers of different values with 8" tinned leads soldered on to the terminals. I use these again and again in different projects.

Over time, you'll accumulate a collection of stock components, and these are handy. But, you can buy a variety box of resistors and capacitors from Joe's Knows Electronics for about $20/ea that will cover most of the bases and will also put the components in nicely labeled and compact baggies for storage in the box. The component quality is certainly good enough for experimenting with breadboards.



 

Offline blewisjr

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Other equipment for testing I should look for
« Reply #35 on: March 28, 2013, 11:03:04 am »
Ok time to revisit the topic now that some stuff is sorted out.

Right now my current lab state looks like this.
Rigol DS1102E oscilloscope
ExTech EX330 multimeter
Hakko FX888 with chisel tip
Flush cutters
Wire strikers
Dremel

Still trying to find
Some other hand tools
Second multimeter
Place to order more part(not sure where I want them from yet comparing prices still)
Power supplies (considering building these myself)

Ok from this point what should I look into I am still sitting around $1k usd of my budget left.
 

Offline David_AVD

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Re: Other equipment for testing I should look for
« Reply #36 on: March 28, 2013, 11:54:42 am »
For hand tools - a good screwdriver assortment as well as an allen key set and a torx driver bit set will be useful.  Also get a good quality pair of combination pliers (don't chop big stuff with your good fine cutters) and a pair of needle nose pliers.  Tweezers are good for placing SMD resistors and capacitors and a scalpel hobby knife with spare blades is good for fine trimming.

Get a couple more tips for the FX888 - a medium conical for general soldering and maybe a fine conical for really fiddly work.

As for a power supply, one of those $80 eBay 3A 30V units will be useful for 95% of your initial projects.  Even when you buy / build something better, that first unit will still be of use.

For audio projects, an old stereo hi-fi amplifier and a set of speakers will serve you well.  Check out eBay, Gumtree or the local "tip shop" for these.  If you don't have an audio oscillator, you can get by for now with a CD player and burning your own test tones with your favourite audio editor software.  To get a variable level output from the CD player, wire up a 10K stereo log pot in a little box with RCA input and output sockets.

A logic probe can be handy - just don't buy the $10 ones on eBay as they are useless.  I found this recently (but the seller did refund the sale after a nudge).  For more serious digital work a logic analyser is good - I like my Saleae Logic unit.

For projects involving serial comms, those FTDI based USB-Serial boards (~10 on eBay) are a great way to get serial data in and out of your PC.   Use with your favourite serial terminal software - lots of free ones out there.
 

Offline dr.diesel

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Re: Other equipment for testing I should look for
« Reply #37 on: March 28, 2013, 11:55:25 am »
Ok from this point what should I look into I am still sitting around $1k usd of my budget left.

Do you have a computer at/near your workbench?  Nothing special is needed, but being able to search datasheets etc is very useful. 

I keep my monitor on the desk with the computer on the floor, don't have any noise issues with what I do.  Are you doing digital or analog or ?

Offline David_AVD

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Re: Other equipment for testing I should look for
« Reply #38 on: March 28, 2013, 12:06:21 pm »
Yes, having a PC (with two screens preferably) right there at your bench is pretty much essential these days.  It doesn't need to be super powerful, but it does need to be reliable.

I find that a wireless mouse and keyboard is much better than corded versions when they're right there on the bench with you.

As I also keep the PC under the bench, I have serial and USB extensions coming up onto the bench top so I don't have to ferret around the back of the PC to plug something in.

Also remember to backup your project files on a separate drive, preferably in another room.  (my backups are automated local and off-site daily)
 

Offline blewisjr

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Other equipment for testing I should look for
« Reply #39 on: March 28, 2013, 12:09:24 pm »
Mostly uC work.  Yes I have a computer for the workbench.  Just have to change a few fans that the kicked the bucket.  I do have a conical tip that came with the iron no sure on the size.  I tend to avoid eBay when possible so I will look around for a pre built supply.
 

Offline madshaman

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Re: Other equipment for testing I should look for
« Reply #40 on: March 28, 2013, 04:11:00 pm »
For your second meter, I recommend this one (plenty of other listings for the same meter): http://www.ebay.ca/itm/FLUKE-27FM-DIGITAL-MULTIMETER-with-Fluke-test-leads-and-Manual-/321096237002?pt=LH_DefaultDomain_0&hash=item4ac2d3bfca&_uhb=1#ht_500wt_1180

I guarantee you won't be disappointed owning one, it'll likely last you forever, and look at the price.
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Offline PA4TIM

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Re: Other equipment for testing I should look for
« Reply #41 on: March 28, 2013, 04:48:50 pm »
https://www.eevblog.com/forum/blog/eevblog-372-fluke-27-multimeter-review-teardown/15/
Here more about this meter. They are over 20 years old and there are several versions, TRMS and not TRMS. But i have a 20 year old Fluke 77-3 and an even older 8020. The 8020 had a bad diplay but I fixed that. The 77-3 is still as good and accurate as new. Amazing..
www.pa4tim.nl my collection measurement gear and experiments Also lots of info about network analyse
www.schneiderelectronicsrepair.nl  repair of test and calibration equipment
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Offline blewisjr

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Re: Other equipment for testing I should look for
« Reply #42 on: March 29, 2013, 10:59:16 am »
Anyone try out the Fluke 77 IV?  Looks like I can get some decent deals on it.
 

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Re: Other equipment for testing I should look for
« Reply #43 on: March 29, 2013, 12:36:12 pm »
No equipment recommendation but related:

Keep your programming place and your soldering place close but separated.
Living next to a 600 kW MW station in the past, I recommend to stock a few ferrite cores  to tame incoming and outgoing RF in case you suppose or prove it is here.
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Offline blewisjr

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Re: Other equipment for testing I should look for
« Reply #44 on: March 29, 2013, 08:54:46 pm »
Just won a Fluke 77-4 off Ebay for $144 USD.  Great deal for a $300 meter.  Lets just hope it is in mint condition as they stated.
 


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