ESR kit builders wanted

I have plenty of experienced guys willing to be a guinea pig but no newbies so far. Unless you count the "newbie" who started in 1956.

You guys are amazing.

John

So what's an 'ESR' ?

As an acronym it means equivalent series resistance to me.

Graham

Follow the link John posted, and ALL will be revealed.

Ask at a local school or college? I assume they still have 'radio' clubs these days?

If it's anything like the last model I found the instructions OK. I suppose I'm pretty experienced, but if there's a 'gotcha' I'm guaranteed to find it. ;-)

I got one real newbie with promise so far. He is interested in electronics, knows what ESR is (or at least wants a meter) and seems willing to learn. A good test.

My thought is that not everyone who buys one of these is experienced with them and that puts a strain on the assembly manual. This is based on our experience when we carried the Dick Smith meter. The manual has to be bullet proof, hence my desire to test it out. The design is solid (thanks Bob) so I have no concerns there.

Yes Bob is still very active. He lurks here occasionally but does not post much.

What a great guy. I am very pleased to have been able to work with him on this project. The label on it gives him well deserved prominence.

John

John.. I am sorta new. Only been in electronics repair since 1944. Never had a ESR meter. Thinking about buying one though. Have done many kits for fun. Even built a lot of test equipment from scratch. So if you get no takers I would try it. Warren

Was the SI (Weber) named after you ? :)))

Looks nice. I've been repairing electronics stuff for 20 years or so, but have never owned an ESR meter. What do you think the price will be for that unit?

I have lots of takers Warren, thanks. The problem is going to be how to fairly pick from them.

John

Our pricing analysis is not quite completed. It takes a fair amount of labor to assemble all of the loose parts into a kit in a logical form. I am trying to reduce that labor cost and hope to be able to keep the kit below $80.

This kit uses all quality parts and includes test leads with 4mm shrouded plugs so you can plug in any termination that you want. Other kits either had no leads or had cheap ones. We will not do cheap.

John

Might I make a suggestion for "improving" the kit?

I assume the "good capacitors" chart is mounted on the outside, where it can be dirtied or damaged. You might want to provide an online PDF so customers can easily replace the chart, or make copies they can tack to the bench shelf, or hold at the distance appropriate to their myopic or presbyopic vision.

I'm curious as to why the test leads and clips are the same color. Shouldn't one be black, the other red?

By the way, your explanation of ESR is clear and (generally) well-written (suck, suck, suck). Just make your sentences a bit shorter (eg, break up compound and complex sentences). Then they'll be perfect. (Salieri)

Sure, all suggestions are welcomed.

I will do that. One of the things that we changed this time is that chart. The original Dick Smith unit had a chart of numbers that Bob had found somewhere. That chart was a source of confusion for those "less experienced" users.

This time I have made a graph with maximum good values for some capacitance values over a wide voltage rating range. I eagerly look forward to feedback as to whether this is better, worse or whatever.

The leads are not polarized, hence the same color. I do wish that I had picked black instead of red as that seems to fit the overall color scheme better. I may change that after the spool of expensive red test lead wire is used up.

Kudos and critiques should be directed to the author, Bob Parker. We just stand on his broad shoulders.

John

I would be interested to see that. I have used a Bob Parker (Dick Smith) since they were first available, and I have never had any trouble relating the chart of 'typical' values to the reality of the actual measurements. I personally feel that the chart is a simple and reliable way of showing what to expect, and I also think that right on the front of the instrument, was the right place for it.

I'm not sure that by changing the chart to a graph, you are not going to be attacking the symptoms, rather than the cause of "less experienced users' " confusion. The measurement of ESR is not a precise thing, like measuring frequency or voltage or resistance or whatever. With the best will in the world, capacitor 'goodness' evaluation by reference to a measured ESR value, requires a degree of interpretation, and that is only possible with experience, so "less experienced user" and capacitor evaluation by ESR measurement, are to some extent mutually exclusive concepts.

I would actually question the need for a casual amateur to own an ESR meter, and also their ability to develop the 'feel' that is necessary to make sensible use of one, given that they are unlikely to be using it on a daily basis for finding a lot of examples of bad caps. As a professional servicing instrument, I would heartily recommend one to anybody, and the original Bob Parker would be the one of choice for value for money, and lack of ambiguity of the display. If the 'new' version is anything like its predecessor, then I'm sure that it will be a fine instrument, but one for casual amateurs ? I'm not too sure ... Perhaps a good write-up on interpreting the results obtained, may have equal or greater value than redesigning the chart that has served so well, in my opinion, to date ??

Arfa

Looks very nice, glad to see the kit will still be around.

If anyone wants to buy the previous Dick Smith/Bob Parker K7214 MK II version I still have a few (30 odd) NOS ones left in stock...plus the MOV modification is free for the remaining kits.

John :-#)#

On Thu, 15 Nov 2007 12:13:03 -0500, John Bachman put finger to keyboard and composed:

I'd be happy with either, although I would advise users of the difference between standard caps and low ESR types. A low ESR SMPS cap that satisfies the "worst case" chart may in fact be faulty.

I use the ESR meter (mark 1) to test the ESR of batteries. It seems to make no difference which way I connect the leads but I'm wondering whether one way is actually better than the other. Maybe you could add typical battery ESR values to your chart ???

- Franc Zabkar

Yes Franc, that's a good point in question, and ably demonstrates my contention that the ESR meter is not a 'beginners' tool, and requires a degree of detailed knowledge to be applied to the indicated result, to allow a valid conclusion to be drawn as to whether the cap in question is indeed at least out of spec, if not downright faulty.

Arfa

On the Mk1 meter, the chart was derived from the worst-case figures in an old capacitor catalog. The Mk2 meter's chart was the end result of night after night of measuring and writing down the figures of all the electrolytic caps in my big collection and more, then averaging them as best I could (some big variations between even unused caps). Most of the people who got confused were the ones who thought ESR is the same as leakage current, and/or that a higher ESR reading is better. I dunno why those people bought an ESR meter kit in the first place.

I've only got skinny little shoulders - goes with my 5' 7" height. :)

I'm also ridiculously busy, which is one reason I'm not seen on newsgroups much these days. Please, no e-mails unless they're important.

Finally a big "Hi!!" to Mr Charles Schuler!! I'm still around, but I rarely look at this NG unless someone tells me there's something I should look at here.

Thanks Bob

Hi Bob - good to see you on here again. Even if that original chart was just cribbed from a catalogue, it has served me well over the years as a good 'indicator' of what to expect. And that, I'm sure, is all that any chart or graph referenced to an ESR meter, can ever be. Using an ESR meter is a bit science and a bit art and a bit experience, and if any one of those is lacking, then I think the user will struggle to get meaningful results. That said, I think your original design goes a long way to reducing the need for the first two to something that is easily learnt. I expect that the new one will be just as good.

Arfa

Please post a note when we can order a kit :-)

I have never used an ESR meter, but it feels like a useful tool.