cfharris at erols.com
Mon Dec 3 22:00:37 EST 2007
I haven't done it. I am strictly a mechanical watch guy. I fix
quartz mechanical watches only because I have a couple in my stable.
It is very fine wire, but not finer than is used in little audio
transformers. I believe it is #48. In any case, it is the same
size as most quartz watches use on their stepper motors. Your best
source may be taking apart a quartz watch, or a transistor radio
The original Accutron circuit was designed to operate nominally over
a voltage range of about 1.1V to 1.7V, IIRC. For this to work, requires
phasing, and a few other adjustments to be exactly correct. Running over
1.35V really makes the watch sing. If you leave one on your night stand,
it will drive you nuts! Re biasing the transistor is the correct
thing to do, but most watch guys aren't EE's, so they look for plugin
solutions. There was a company that made an adapter between the old
1.35V Hg cell package, and a modern AgO cell. They included a resistor
in series with the cell to drop the voltage down to a proper level. This
was sanctioned by Bulova. Any of these drop in solutions will waste
power from the cell to the tune of 0.2V x I. Cells wear out on Accutrons
fast enough as it is.
Whatever you do, don't use Wein Cells (Zn-Air). They put out the correct
voltage, but they also emit water vapor in operation. Your watch doesn't
need that. Also, they die in 6 weeks whether you draw current or not. And
they can use up the free oxygen in the watch case if your seals are good.
One source for reasonably priced accutrons is Tom Mister at dashto.com .
He loves the things, and usually has a few on his website. He prices things
to his own ideas of what they are worth... not ebay's.
Daun Yeagley wrote:
> Hi Chuck
> Have you ever attempted, or know someone who has rewound or repaired the coils?
> There was a guy on the Yahoo Accutron list that was experimenting with it, but I
> don't know the final outcome. Seems that wire is thinner than most normally
> available wire.
> Seems that the "usual" way to deal with the silver oxide vs. mercury battery
> problem is to use a schottkey diode in series with the battery (there's even
> someone marketing a battery assembly with the diode imbedded, called an
> Accucell). I've been thinking all along that the best way to do it is to
> re-bias the transistor. I've wanted to experiment with that, but I need to come
> up with another Accutron, as I don't want to ruin the Spaceview that I got from
> my wife on our first Christmas way back in '67! Know any reasonable sources?
> I've been looking on Ebay, but they always seem to get bid way up, even for one
> that doesn't run.
> Glad to get another time-nuts take on this!
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