Bob Parker ESR Meters

[akuhon]

Re: Bob Parker ESR Meters

Hai Bob,

I just got your device ..... it's really helpful.

I'm identifying several capacitors available from the electronic market component .....
So, now I'm not a afraid of counterfeit / fake / rebadge product....

Here's Rubycon cap... the device give the same result as the datasheet (0.046 ohm) ...



But I also see, in every capacitor's datasheet, there's a measurement of ripple current (mA r.m.s.)
Do you think this measurement is also important ?
How to do it, any idea ? Or maybe you can make it, combine with your existing ESR Meter for the next version (Mk.III) ?

Cheers,

[Bob Parker]

Re: Bob Parker ESR Meters

Unfortunately, I missed the sale on that particular version T2200 (meter), but I did land it's little brother T1976 (minus meter), BTW thanks for the pointer(s) always appreciated

The 17w ~ 25w hobbist irons are quite nice IMHO, but their tips don't make fine/detailed soldering easy by any means... but I digress

Temperature controlled irons (set to a sensible temperature of course!) are almost essential when you're working with PCBs. Uncontrolled irons are OK for tinning the ends of bits of cable etc which are pretty hard to damage with excess heat.

[Bob Parker]

Re: Bob Parker ESR Meters

Hai Bob,

I just got your device ..... it's really helpful.

I'm identifying several capacitors available from the electronic market component .....
So, now I'm not a afraid of counterfeit / fake / rebadge product....

Here's Rubycon cap... the device give the same result as the datasheet (0.046 ohm) ...



But I also see, in every capacitor's datasheet, there's a measurement of ripple current (mA r.m.s.)
Do you think this measurement is also important ?
How to do it, any idea ? Or maybe you can make it, combine with your existing ESR Meter for the next version (Mk.III) ?

Cheers,

The data sheets generally tell you the highest ESR which can be expected for a specific capacitor type/model. Mostly they're a bit below that figure at 25 degrees C.

ESR is a very variable kind of thing, and don't forget that it changes quite dramatically with temperature (ESR drops as temperature rises). This is one reason why it's better to check capacitors in-circuit if possible. Otherwise the heat from de-soldering them makes the ESR decrease until they cool down again, making them look better than they really are.

Ripple current is a maximum rating for a capacitor. It's the largest AC current you can safely pass through it. That's what mA RMS means. It's like voltage rating .... it's about what the circuit's doing to the capacitor, not a characteristic the capacitor itself has.

[akuhon]

Re: Bob Parker ESR Meters

Thanks Bob,

That helps ......
How about a new / fresh (never used) caps ? If I test with this ESR meter, will the result be valid ?

Thanks ...

[Bob Parker]

Re: Bob Parker ESR Meters

Thanks Bob,

That helps ......
How about a new / fresh (never used) caps ? If I test with this ESR meter, will the result be valid ?

Thanks ...

I'm not really an 'ESR Meter Guru' . I'm just a technician who was repairing switching power supplies and I desperately needed to know the condition of their capacitors. I'm not an expert on every detail of electrolytic caps. I can only tell you my experience after using the ESR meter since 1995.

Most new electrolytic caps have an ESR a bit below what their datasheets say. It will stay low for a very long time unless the capacitor has been operated at a temperature considerably above room temperature, especially if it has high ripple current through it.

Of course this doesn't apply to the billions of faulty electrolytic caps which are the reason that this Badcaps forum exists! They will keep getting worse as long as they have DC across them.

So the ESR of an unused electrolytic cap will be very similar to what it would be if it had been in use for a while, under normal temperature/ripple current conditions.

There is a lot of information about electrolytic caps and what to expect when using an ESR meter in the kit notes for the Dick Smith ESR meter. Anyone can download it from

But I don't have time to answer lots and lots of question about it.

[akuhon]

Re: Bob Parker ESR Meters

Hi Bob...

Thanks for your comment and I really thank you for making this great device.


Cheers,

[starfury1]

Re: Bob Parker ESR Meters

Hi all

A page on capacitance and ESR Here

Bit on the techie side and uses maths you may have to search out the definitions of some terms, properties to make sense of it.

heres another page with links off it including Bob Parkers page

ESR Testing

Hope it helps anyway

Cheers

[PeteS in CA]

Re: Bob Parker ESR Meters

ESR is a very variable kind of thing, and don't forget that it changes quite dramatically with temperature (ESR drops as temperature rises). This is one reason why it's better to check capacitors in-circuit if possible. Otherwise the heat from de-soldering them makes the ESR decrease until they cool down again, making them look better than they really are.

Ripple current is a maximum rating for a capacitor. It's the largest AC current you can safely pass through it. That's what mA RMS means. It's like voltage rating .... it's about what the circuit's doing to the capacitor, not a characteristic the capacitor itself has.

Lytic caps' ESR have a strong negative tempco - lower ESR at higher temp and higher ESR at cold temps. Caps with water-based electrolytes are typically only rated down to -40C, while non-aq low Z types are typically rated down to -55C. At 25C, good low Z caps have a lower Z/ESR than their max rating. Theoretically, the ripple current rating means that if you run caps above that rating, hydrogen gas will be produced, leading to premature failure. I don't recommend exceeding that rating on a long-term, full-time basis, but it is a conservative rating. I've run caps in one of my tests at multiples of their ripple current rating (at room temp) and had some last for thousands of hours. Re discharging caps, I have a jig made of two power resistors in series formed like tweezers so I can discharge the caps I'm testing while gripping the resistors by their bodies (IOW, I don't get zapped, ). I discharge every cap (and let them cool for two hours - it's an engineering tests) before checking them on my LCR meter.

[Bob Parker]

Re: Bob Parker ESR Meters

Theoretically, the ripple current rating means that if you run caps above that rating, hydrogen gas will be produced, leading to premature failure.

I've just done a whole lot of net searching to find out more about ripple current causing hydrogen liberation in electrolytic caps and can't find a thing. The manufacturers say hydrogen generation is a function of DC leakage, and ripple current simply causes I2R heating.
Can you please direct me to more info on this subject? Thanks.

[PeteS in CA]

Re: Bob Parker ESR Meters

Wellllllllllllllll ... these two pages from UCC say it indirectly:
http://www.chemi-con.com/u7002/life.php
http://www.chemi-con.com/u7002/failure.php

The failure chart points out that excessive ripple current causes increase internal pressure. The life page points out that excessive ripple current causes oxide formation on the cathode foil. Hydrogen gas is a byproduct of oxide formation and the cause of the rise in internal pressure.

[Bob Parker]

Re: Bob Parker ESR Meters

Hmmm, OK. Thanks for that.

[Bob Parker]

Re: Bob Parker ESR Meters

Hi Bob...

Thanks for your comment and I really thank you for making this great device.

Cheers,

I'm happy that this meter I originally only designed for me is useful to lots of others who are having problems with Bad Caps.

Just for everyone's information, Dick Smith Electronics down here in Australia has completely gotten out of the kits business. No more ESR meters are going to be produced.

Most of the remaining stock of them is now at John's Jukes in Vancouver, Canada. He ships world-wide and his prices and customer service are good.

His website is at http://www.flippers.com

[K7214]

Bob Parker's ESR kit still available!

Caution - blatant, self-serving ad!

If anyone here is looking for the Dick Smith (DSE) K-7214 ESR kit for measuring electrolytic capacitors in circuit please feel free to visit:

http://flippers.com/esrktord-form.html for more info.

I have about 150 left in stock.

John :-#)#

PS, for those of you that already have the kit Bob set up a poll to find out if folks wanted the meter continued as a kit or pre-assembled you can find it at the top of our ESR support page:

http://flippers.com/esrkthnt.html

[Sp@rtacus]

Re: Bob Parker ESR Meters

Hi, can you help me with a HEX file for blue esr for microcontroller??

[dumpystig]

Re: Bob Parker ESR Meters

ESR... ripple current... hydrogen liberation...

Christ, we're talking about one type of many different components on any PCB - basically if it looks buggered or I think it may be buggered then I replace it, sometimes on a somewhat trial-and-error basis, but almost always with success.

[Agent24]

Re: Bob Parker ESR Meters

Hi, can you help me with a HEX file for blue esr for microcontroller??

I doubt that is going to happen any time soon.

Look on Google, there are many other ESR meter designs available and with source code, if you want to make something yourself.

[Sparks88]

Re: Bob Parker ESR Meters

hi, i would like to find the blue esr meter for sale in the uk or europe, this is because anything from the US will get me hammered by the dreaded vat and import duty then royal mail also get their pound of flesh, any info appreciated.Thanks in advance.

[Bob Parker]

Re: Bob Parker ESR Meters

hi, i would like to find the blue esr meter for sale in the uk or europe, this is because anything from the US will get me hammered by the dreaded vat and import duty then royal mail also get their pound of flesh, any info appreciated.Thanks in advance.

I don't know if it's of any use to you, but the EVB ESR meter from Portugal is almost the same as the Blue meter from Anatek Corp. Its web page is at http://clientes.netvisao.pt/greenpal/evb1.htm

[Sparks88]

Re: Bob Parker ESR Meters

I don't know if it's of any use to you, but the EVB ESR meter from Portugal is almost the same as the Blue meter from Anatek Corp. Its web page is at http://clientes.netvisao.pt/greenpal/evb1.htm

Thank you, i was concerned about charged caps but i see that the meter can be ordered with protection diodes.

[ksor]

Re: Bob Parker ESR Meters

Has any of you experiences with the ERS meter kit "K 7214" from this firm:

http://clientes.netvisao.pt/greenpal/evb1.htm

Good or bad ?