Need coil for Hammond Firefly

Discussion in 'Electric Horology' started by JimBowen, Apr 28, 2020.

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  1. JimBowen

    JimBowen New Member

    Apr 28, 2020
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    Hi All! Just joined this forum for help with my old clock! I have what I believe is a Hammond Synchronous Firefly clock. The only official markings are the patent numbers on the back (and the logo on the dial.)

    Anyway - it stopped working many years ago, and I fiddled a bit but had no luck. About a week ago I decided to tear it down. It's now all apart, and there is evidence of the coil overheating.

    With my very basic electrical skills and a rudimentary digital multimeter, I can detect no connectivity in the coil, nor in the other side of the coil used for the light bulb. So I opened the outer layer of the coil, and found that one of the 'feed' wires was broken from the coil, so I replaced it with a segment of new blue wire. The other is still connected, but I'll replace that eventually. But - even with that new connection, I still get nothing from the bulb-side of things.

    I will accept any suggestions for other things to test! I don't think I have the patience or skills to re-wind the coil, so I will gladly purchase a new or 'good' coil if available.

    I'm going to try to attach a few pics.

    Thanks in advance for all of your advice!
    Jim 20200426_161024 (Large).jpg 20200426_162548 (Large).jpg 20200426_162558 (Large).jpg 20200426_183539 (Large).jpg
  2. David S

    David S Registered User
    NAWCC Member

    Dec 18, 2011
    Professional Engineer - Retired
    Brockville, On Canada
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    Welcome to the forum Jim,

    Perhaps a moderator will move this over to the electrical horology forum for better coverage.

  3. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    Self employed interpreter/clock repairer
    North Carolina
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    The likelihood of finding a coil is slim. I'll move this over to electric horology and see if they can point you in the right direction.
  4. davefr

    davefr Registered User
    NAWCC Member

    Nov 29, 2008
    Semi Retired Engr. Mgr - Currently Rebuilding Tele
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    Did your coil repair restore the primary circuit which is to energize the magnetic field to power the clock motor? If so, does the clock's case have room for a second coil who's only purpose is to supply the low voltage AC for the bulb? If so, that opens the door to many options including using only the secondary circuit from a more common 2 circuit coil (ex: Telechron coil).

    Other then that, I see your only options are to find a rewinding service or look for a parts clock on Ebay.

    There were a gazillion old clock motor manufacturers/motor options and unfortunately most of them are unobtainium today or very labor intensive to rebuild/restore.

    P.S. These guys claim they'll rewind anything:

    RODALCO Registered User

    Mar 27, 2006
    New Zealand
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    Rewinding will be your best option. If possible make an estimate of how many turns per layer and how many layers to the center. Most low power coils can have between about 12,000 and 7,000 turns for 127 Volt coils.
    Rewind the coil for 12 Volts with around 1,000 turns and use a small 120 / 12 Volts transformer to run the coil.
    Copper wire can easily taken out of an old microwave oven fan motor, or deflection coils from an old CRT TV. or purchase some on the web.
    Good luck with it and worth having a go at repairing that coil.
  6. Kevin W.

    Kevin W. Registered User
    NAWCC Member

    Apr 11, 2002
    I work at the Veritas Tools machine shop.
    Nepean, Ontario, Canada
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    I found a few companies local to me that rewind motors, but had insane charges for it. Something like 500 Can.

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