User's report on solid state thyratron replacement
Close
Login to Your Account
Results 1 to 9 of 9
  1. #1
    Join Date
    Nov 2004
    Location
    Webster Groves, MO
    Posts
    7,462
    Post Thanks / Like
    Likes (Given)
    1899
    Likes (Received)
    3482

    Default User's report on solid state thyratron replacement

    For over ten years I have been playing ring around the rosy with thyratrons on a Modular 10EE. One of the problems has been that it is in a shop where any of a dozen people can use it and most of them think that once they have hit the stop buton, no further action is needed. Frequently the tyratrons would be lit with no one running it because the last user went off with it still energized. One tube finally burned out and we had pretty well used up the spares. We bought a pair of Scissio's solid state replacements and I installed them yesterday. They really are drop in (or more accurately bolt in) replacements. They ran right off the bat and a little tweaking of the max speed and IR Comp controls was all that was needed.

    We will have to see how they hold up in service, but for now they get 5 stars.

    Now, if someone would make a solid state replacement for the C3J, we could be rid of thyratrons.

    Bill

  2. Likes TDegenhart, DualValve, Cal Haines liked this post
  3. #2
    Join Date
    Sep 2002
    Location
    Salinas, CA USA
    Posts
    4,056
    Post Thanks / Like
    Likes (Given)
    241
    Likes (Received)
    210

    Default

    Don't you miss that purple glow? Seriously, this is great news. Between these thyratron replacements and the modular box replacement, the DC drives ought to go another 100 years. How hard would it be to build a modular from scratch, using these components?

  4. #3
    Join Date
    Jul 2019
    Country
    UNITED STATES
    State/Province
    California
    Posts
    35
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    5

    Default

    You didn't mention where you bought yours or what they cost, 10EE owners want to know. :-)

  5. #4
    Join Date
    Sep 2002
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    3,683
    Post Thanks / Like
    Likes (Given)
    878
    Likes (Received)
    495

    Default

    Quote Originally Posted by teletech View Post
    You didn't mention where you bought yours or what they cost, 10EE owners want to know. :-)
    For Monarch 10ee Lathe

  6. Likes teletech liked this post
  7. #5
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    28,788
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8936

    Default

    Quote Originally Posted by rimcanyon View Post
    Don't you miss that purple glow? Seriously, this is great news. Between these thyratron replacements and the modular box replacement, the DC drives ought to go another 100 years. How hard would it be to build a modular from scratch, using these components?
    Need the transformer and the rest of the trigger and control circuits, DC panel with contactors and biased relays, complex "motor" switch, ganged rheostats...

    But why wudja?

    I'm a fan of restoring "whatever" Monarch shipped - because it was all "tuned and tested" to work well together, and has PROVEN that it does. These components righteously DO that "preservation of the well-proven goodness" thing. No hassle. No surprises. No re-engineering for each install. It was shipped matching the published manual & schematics. It does so once again, Hundreds of other hands can help yah. You get to "go make chips", and with minimal distraction.

    That said? You would still have only a contactor-reversed, FIRST Quadrant DC Drive, "tubes" or not, no matter how well you executed to OEM plan.

    Easier way, better results if yah have to work "from scratch"?

    Some among us do not need to "make chips". We have done yer R&D for yah instead.
    No special reason. Just because we could. DC Drives my interest. VFD or even servos, other curious souls.

    DC Drives:

    Same transfomer plus a modest booster, or any of many other common transformers, plus a (Eurotherm)/Parker 514C-16 DC Drive? Now you have ZERO contactors, field-acceleration/braking relays, ZERO braking resistors, not even the old motor control switch. ONE "Single knob control" can be ALL OF: ON, in which direction, at what speed, braking & how rapidly, and OFF.

    EG: NO DC panel. No braking resistors needed at all.

    All that and more - far better load regulation at the head of the list - is built-in because it is a FOUR Quadrant DC Drive.

    Even easier if you have decent three-phase power available.

    A 3-P (only) DC Drive doesn't even need a transformer, and will usually have Field Regulator circuitry as a plug-in option, if not already right on PCB.

    IOW .. Modular "First Quadrant" drive makes sense as a restoral of what is mostly already there, already paid-for, already has its parts and wiring laid-out and fastened in place.

    It does NOT make much sense from a "cold-start", empty casting or one to be "gutted" vs a packaged "4Q" AKA "regenerative" DC Drive, either 3-P or 1-P.

    Yah might save a few bucks? Only at the cost of development time vs just setting the built-in options on packaged drive with a tiny screwdriver or a numeric keypad & display.

    Until you have to try to repair or duplicate-from scratch that DC panel and its biased sensitive relays. Now you have work to do that a "packaged" 4Q drive already has built-in - Analog Logic OR Digital - and at no extra charge.

    The coloured light show?

    THAT can be simulated with Argon glow lamps. Or even LED's!

    Even the characteristic 120 Hz "growl" can be simulated, but subbing-in the
    William Tell overture, Ride of the Valkyries, or the Battle Hymn of the Republic might be a bit "over the top"?

    ..Sez he once asked if a custom bit of telco test gear he was building could "bark like a dog"... and made it do exactly that... with a "talking clock " chip and one extra screen of forth code, base six notation.

    Keyboard-in the word "bark". Hit return. It barked like a dog!

    Things young men will DO for cute blond gals are .. well... whatever they WANT, yah?

    More to life than just "making chips".

    Last edited by thermite; 03-19-2020 at 01:18 PM.

  8. Likes Yan Wo liked this post
  9. #6
    Join Date
    Sep 2002
    Location
    Salinas, CA USA
    Posts
    4,056
    Post Thanks / Like
    Likes (Given)
    241
    Likes (Received)
    210

    Default

    Ok, let me redefine "starting from scratch": suppose you have a WIAD machine as the starting point. That means you have aging insulation, components that are obsolete, a system that has probably been overheated for many years. By comparison a modular machine has components that are largely still available, it is more reliable, less prone to overheating. The DC panel is much simpler. The machine wiring is vastly simpler. However, and this is a crucial thing to keep in mind, the modular is a direct evolutionary step from the WIAD, it is not a total new species. There are more similarities than differences between modular and WIAD. Now we have two recent developments that take the evolution one step further, and they apply to both members of the family: solid state thyratrons and replacement diode boxes. But that doesn't solve all the problems, especially for WIAD. So what is the logical next evolutionary step, one that would be in reach of the avg 10EE tinkerer, since that by definition includes all present company that owns a running 10EE with a DC drive.

    So as a starting point, you have all the transformers, they seldom go bad. The real question is, was I correct in the last paragraph? Are all the necessary components available to build a modular? Or even better, are there components available to simplify the design of the modular even further? One quandrant, four quadrant, breaking resistor - all that is food for discussion.

  10. #7
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    28,788
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8936

    Default

    Quote Originally Posted by rimcanyon View Post
    Ok, let me redefine "starting from scratch": suppose you have a WIAD machine as the starting point. That means you have aging insulation, components that are obsolete, a system that has probably been overheated for many years. By comparison a modular machine has components that are largely still available, it is more reliable, less prone to overheating. The DC panel is much simpler. The machine wiring is vastly simpler. However, and this is a crucial thing to keep in mind, the modular is a direct evolutionary step from the WIAD, it is not a total new species. There are more similarities than differences between modular and WIAD. Now we have two recent developments that take the evolution one step further, and they apply to both members of the family: solid state thyratrons and replacement diode boxes. But that doesn't solve all the problems, especially for WIAD. So what is the logical next evolutionary step, one that would be in reach of the avg 10EE tinkerer, since that by definition includes all present company that owns a running 10EE with a DC drive.

    So as a starting point, you have all the transformers, they seldom go bad. The real question is, was I correct in the last paragraph? Are all the necessary components available to build a modular? Or even better, are there components available to simplify the design of the modular even further? One quandrant, four quadrant, breaking resistor - all that is food for discussion.
    Deends on how much "love" yah have for "Hollow State". By definition, that ain't MUCH if yer giving-up the "fire bottle" Thyratrons and light-show for the SCR packaged units.

    It isn't HARD nor expensive to gin-up a replacement for the entire functionality of the DC panel, either. I haven't much bothered to delve the details, but I've tailored PLENTY of stock "plate-sensitive" relays to do Analog'ish stuff - act within a specifc Current or Voltage range.

    Lots of folks have made coils and rebuilt the OEM ones. Same gain, less pain to just adapt current items. Same as the OEM ones were "tailored", actually.

    If a WiaD or Modular doesn't NEED much? Resotral is cheapest, and a road well-traveled.

    More on conversion cost and effort, separate post.

    Time to go and "un-hoard" a Cantonese steak and lobster dinner before it gets cold(er).

  11. #8
    Join Date
    Nov 2004
    Location
    Webster Groves, MO
    Posts
    7,462
    Post Thanks / Like
    Likes (Given)
    1899
    Likes (Received)
    3482

    Default

    Quote Originally Posted by rimcanyon View Post
    Don't you miss that purple glow?
    Not a bit. When I was 20 years old, in 1955, I went to work at Greenleaf Manufacturing. My first assignment was sorting out nuts and bolts, then I was handed a schematic for a gyro temperature control that used a 2D21 miniature thyratron to control a relay. I got it working but when I leaned over it, blocking some light, the firing point changed. It changed with temperature, phases of the moon and the receptionist's menstrual cycle. It also got me some bad press from the vice president because it was such a mess from countless changes, trying to make it work logically.

    Finally, I drew up a schematic using a 6BN6 tube to sense the output of a thermistor bridge. The 6BN6 was an FM discriminator that had almost snap action in this service. It worked so well that it became the standard control for our gyro test systems, my first commercial success.

    After a lifetime of working with mercury vapor rectifiers, gas lasers, and other assorted argon, xenon, and other gas filled things, the glow from 10EE tubes just means having to keep changing them until I get a matched pair. Good riddance. If anyone wants something to light up, I have some big thyratrons I got in a package deal I bought for the ignitrons, I can make you a good deal.

    The link Cal listed doesn't work right now, but it should be good in a while.

    The replacements were for a customer's lathe and their purchasing agent bought them, so I don't know the exact price, but I think it was around $175. Don't hold me to that, just an imperfect memory.

    Bill

  12. #9
    Join Date
    Nov 2004
    Location
    Webster Groves, MO
    Posts
    7,462
    Post Thanks / Like
    Likes (Given)
    1899
    Likes (Received)
    3482

    Default

    [QUOTE=9100;3511505]

    The replacements were for a customer's lathe and their purchasing agent bought them, so I don't know the exact price, but I think it was around $175. Don't hold me to that, just an imperfect memory./QUOTE]

    Even cheaper, $136.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •