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  • Ultrasonic cleaners

    From bitrex@21:1/5 to All on Wed Sep 25 23:24:18 2024
    Any serious gotchas/unobtainium parts with respect to repairing these 1980s/90s(?) Branson ultrasonic cleaners?

    <https://d2b3o1qijggx1c.cloudfront.net/full-version-images/1200-Ultrasonic-Cleaner_0.JPG>

    I'd like one to have around for cleaning parts in the lab but
    good-quality ones tend to be more than I want to spend; I probably won't
    use it that often, I can get a 1200 series that doesn't seem to
    ultrasound for a few bucks though.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dave Platt@21:1/5 to user@example.net on Sun Oct 6 13:07:59 2024
    In article <66f4d3b5$1$1427964$882e4bbb@reader.netnews.com>,
    bitrex <user@example.net> wrote:

    Any serious gotchas/unobtainium parts with respect to repairing these >1980s/90s(?) Branson ultrasonic cleaners?

    <https://d2b3o1qijggx1c.cloudfront.net/full-version-images/1200-Ultrasonic-Cleaner_0.JPG>

    From what limited knowledge I have of them, I suspect that there are probably two major points of possible failure:

    - The ultrasonic transducers may have reached end of life (cracked?), or
    de-bonded from the steel tank.

    - The ultrasonic oscillator may have failed. These often seem to be
    resonant oscillators (a suitably-chosen C, interacting with
    the L of the transformer) driven from the rectified mains voltage,
    with one or two high-voltage NPN transistors or MOSFETs as the
    switching elements.

    For either of these cases, there are probably suitable generic replacements available. The trickiest part might be removing a failed transducer from
    the tank, and the securely bonding its replacement (presumably with some sort of epoxy but I don't know what type).

    A good friend of mine had acquired a Quantrex 125-watt cleaner which wouldn't sonicate at all. His testing showed that the two NPN power transistors in the oscillator were dead... and he wasn't particularly complementary about the arrangement which held them to the aluminum bar which served as a heat-sink. They
    may just have overheated and cooked, after years of service, or shorted to the heat-sink and fried themselves.

    The specific parts in question were unobtanium. I looked around on DigiKey
    and found some modern parts which looked like suitable replacements... better voltage and current and dissipation ratings, similar package, and not expensive. I included a few in my next order, and handed them to my friend along with a couple of suitable-sized mica insulators left over from my amplifier-building project. He installed the new parts (with proper
    silicone grease), and the cleaner came back to life and makes plenty of cavitation.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to Dave Platt on Wed Oct 9 13:10:21 2024
    On 10/6/2024 4:07 PM, Dave Platt wrote:
    In article <66f4d3b5$1$1427964$882e4bbb@reader.netnews.com>,
    bitrex <user@example.net> wrote:

    Any serious gotchas/unobtainium parts with respect to repairing these
    1980s/90s(?) Branson ultrasonic cleaners?

    <https://d2b3o1qijggx1c.cloudfront.net/full-version-images/1200-Ultrasonic-Cleaner_0.JPG>

    From what limited knowledge I have of them, I suspect that there are probably
    two major points of possible failure:

    - The ultrasonic transducers may have reached end of life (cracked?), or
    de-bonded from the steel tank.

    - The ultrasonic oscillator may have failed. These often seem to be
    resonant oscillators (a suitably-chosen C, interacting with
    the L of the transformer) driven from the rectified mains voltage,
    with one or two high-voltage NPN transistors or MOSFETs as the
    switching elements.

    For either of these cases, there are probably suitable generic replacements available. The trickiest part might be removing a failed transducer from
    the tank, and the securely bonding its replacement (presumably with some sort of epoxy but I don't know what type).

    A good friend of mine had acquired a Quantrex 125-watt cleaner which wouldn't sonicate at all. His testing showed that the two NPN power transistors in the
    oscillator were dead... and he wasn't particularly complementary about the arrangement which held them to the aluminum bar which served as a heat-sink. They
    may just have overheated and cooked, after years of service, or shorted to the
    heat-sink and fried themselves.

    The specific parts in question were unobtanium. I looked around on DigiKey and found some modern parts which looked like suitable replacements... better voltage and current and dissipation ratings, similar package, and not expensive. I included a few in my next order, and handed them to my friend along with a couple of suitable-sized mica insulators left over from my amplifier-building project. He installed the new parts (with proper
    silicone grease), and the cleaner came back to life and makes plenty of cavitation.




    Hi, thanks for getting back. The used unit I picked up seems to
    ultrasound pretty good and passes the aluminum foil test, putting lots
    of tiny holes in it...it's perhaps not in perfect adjustment but
    probably will work well enough for my purposes which isn't much more
    than cleaning various electronic bits, toy train parts, and maybe my girlfriend's jewellery from time to time.

    Heater seems bad (can hear relay switching but no heat) but that's
    probably an easier fix, though I haven't had time to dig into it.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From wmartin@21:1/5 to bitrex on Wed Oct 23 15:58:33 2024
    On 9/25/24 20:24, bitrex wrote:
    Any serious gotchas/unobtainium parts with respect to repairing these 1980s/90s(?) Branson ultrasonic cleaners?

    <https://d2b3o1qijggx1c.cloudfront.net/full-version-images/1200-Ultrasonic-Cleaner_0.JPG>

    I'd like one to have around for cleaning parts in the lab but
    good-quality ones tend to be more than I want to spend; I probably won't
    use it that often, I can get a 1200 series that doesn't seem to
    ultrasound for a few bucks though.


    Branson stuff of that era is/was top quality laboratory-grade hardware,
    you can probably find a repair shop to snag replacement transducers,
    should they be bad.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)