Seth Thomas Self-winding No 1 (86A) power question

Discussion in 'Electric Horology' started by TJ Cornish, Nov 28, 2018.

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  1. TJ Cornish

    TJ Cornish Registered User
    NAWCC Member

    Sep 12, 2013
    St. Paul, MN
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    I picked up a Seth Thomas Self-winding no. 1 clock with an 86A movement in it. Originally it was powered by a pair of gigantic 1.5v lantern batteries. I overhauled the movement (disassemble, ultrasonically clean, reassemble, oil) and I have it running on about 5 volts. It runs reliably down to about 4 1/2 volts, but below that, the solenoid doesn't have enough power to fire. I measured peak current draw at just under 700mA, and this number doesn't seem to change as I tweak the voltage. I'm aware that too much voltage is hard on the contacts, but just under 5v seems to be the minimum it's reliable. Is this a major concern?

    Also, I have noticed that if the clock is fully wound down and the pin is resting on the contact, sometimes the clock doesn't have enough power to fire. It is reliable if I push the weight up and let it wind down and touch the contact.

    Thanks for your thoughts,

    IMG_5901.jpg IMG_5902.jpg
  2. THTanner

    THTanner Registered User
    NAWCC Member Donor

    Jul 3, 2016
    Carson City, Nevada
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    I have seen 6 volt set ups in these and that extra volt is not likely to cause any problems.
  3. mrpat2

    mrpat2 Registered User
    NAWCC Member

    Aug 17, 2018
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    did you get a resolution? you dont say what your power source is, those big batteries that were there maybe could provide more amperage to fire the solenoid than what your power source can provide. Momentary current draw of something higher shoudnt hurt anything
  4. James McDermaid

    James McDermaid Registered User
    NAWCC Member

    Apr 29, 2011
    #4 James McDermaid, Mar 23, 2019
    Last edited: Mar 23, 2019
    The case looks big enough to hold 4 of the #6 dry-cell batteries. That would give you 6 volts if connected in series. The original #6 is about the size of that battery in the upper left I believe.

    There are new versions of the #6 being made but expensive. If you find the clock is meant to run on 6 volts I would use 4 "D" cells in series as I am led to believe a pair of "D" cells are the same Ampacity as the old #6 was back-in-the-day. So to get a year you could find some new battery clips that hold 4 "D" cells in series and use two in parallel.

    Eveready went out of business some time ago, there are some folks making some batteries however, including the #6.

    There are fake #6 batteries that contain "C" or "D" cells and those of us that play with old radios print antique labels and apply them to the fake #6, I use one in my Eureka Clock.

    I would think a clock of the age of yours would use very standard batteries of the period like the good ole #6. Self Winding Clock Co use two #6 in there clocks which ran it a year plus. 1.5 volts each for 3 volts.


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