Connect with us

ESR kit builders wanted

Discussion in 'Electronic Repair' started by John Bachman, Nov 14, 2007.

  1. Of course. So why are you soliciting testers? <grin>

    Here's another reason why you might want to consider me for the
    "experienced" role.

    Back in 1980 I assembled several Hafler XL-280 amps. There was one spot
    where the otherwise-excellent instructions got Really Dumb. The sequence was
    clearly "wrong". I asked the writer -- the late, lamented Bob Tucker, who'd
    done many of the Dyna manuals -- what was going on. He explained that one of
    the requirements to reduce assembly errors was to minimize the number of
    unsoldered connections at any one time.
  2. 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

    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)
  3. Smitty Two

    Smitty Two Guest

    And yet *another* reason to use liquid flux. It's virtually impossible
    to bridge things while using it.
  4. John Bachman

    John Bachman Guest

    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.

  5. Arfa Daily

    Arfa Daily Guest

    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 ??

  6. 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 the
    MOV modification is free for the remaining kits.

    John :-#)#

    (Please post followups or tech enquires to the newsgroup)
    John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
    Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
    "Old pinballers never die, they just flip out."
  7. Franc Zabkar

    Franc Zabkar Guest

    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
  8. Arfa Daily

    Arfa Daily Guest


    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.

  9. Bob Parker

    Bob Parker Guest

    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.

  10. Arfa Daily

    Arfa Daily Guest

    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.

  11. Please post a note when we can order a kit :)

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

    John Bachman Guest

    I expect to have the new design available Nov 26, maybe a day or two
    earlier. You will be able to order it at An "Add to cart" button will be there
    when it is available, also a price. We will also offer it fully
    assembled, tested and aligned.

    If you are in a hurry you can still get the EVB kit at We have a few of them in stock. The
    EVB meter is also a fine design by Bob Parker.

  13. Guest

    I am interested in building your kit.

    I am an electronic hobbyist; maintain my home stuff as much as
    possible. Own instruments such as TEK 2336 Scope, Digital VOM and LCR
    Meter. Used to fix home audio stuff, TVs etc. about 15 years ago.

    As part of hobby, developed analog H/W interface between my Laptop
    modem and cordless phone handset which worked and allowed me to
    connect the modem to phone line from anywhere in the house within the
    range of that cordless phone.

    However, my hobby is managed as my time permits which is not on a day-
    to-day basis.

    Have read about Bob Parker's ESR meter article on the net. Found the
    concept very interesting; Wanted to build that but it is not available
    here locally.

    I am a regular visitor to this NG and find some of the discussion
    threads very stimulating.

    Considering the experience and expertise that is around on this NG, I
    may be considered as little experienced "Newbee".

    Warm Regards,

  14. John Bachman

    John Bachman Guest

    <snipped the rest>

    Sorry, but you are too late. I have picked the testers from the many

    Thanks for trying.

  15. Guest

    No harm done. At least I can say I tried !!

    With Warm Regards,

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day