Means of dropping watch battery voltage by .2 Volts

[D]

I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage
Bulova Accutron wristwatches. These watches operate using a very basic
oscillator circuit which energizes a tuning fork via a pair of coils.
The tuning fork then drives the mechanical movement of the timepiece. A
basic description can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

These are very cool watches to the collector. They are stylistically
very much of their era, and because of the tuning forks, they hum,
rather than tick. The problem is, these watches were originally
designed to run on a 1.35 volt mercury oxide cell (343) which is no
longer available. There is a 1.55v silver cell which will fit, but it
can cause some Accutrons to run very fast, and possibly even damage
them. At least one supplier sells modified cells with a component to
drop the cell's voltage to 1.35 volts. I think this is accomplished
with a surface mount type diode. Here's a thread on these cells in a
watch discussion, with pictures of the component added
http://bdwf.net/forum/showthread.php?t=75397 I would like to simply
insert an appropriate diode into the circuit of the watches as a one
time modification, after which I can use the much cheaper/readily
available silver cells. But, as I said, my electronic component
knowledge is late 70's vintage, so I'm not sure what component to add. I
know in general silicon diodes have a forward voltage drop on .7V,
germaniums, .3V, so I'm not sure how to produce .2V. A zener? A
Schottky? Anyone have any suggestions on what would lower the output
of the 1.55 volt cells to 1.35 volts, over the life of the cell? It
would have to be fairly small, about 1/2 the size of a 1/4 watt
resistor, or less.

TIA

Dan

 

[Sylvia Else]

On 6/07/2011 2:46 PM, D wrote:

I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage Bulova
Accutron wristwatches. These watches operate using a very basic
oscillator circuit which energizes a tuning fork via a pair of coils.
The tuning fork then drives the mechanical movement of the timepiece. A
basic description can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

These are very cool watches to the collector. They are stylistically
very much of their era, and because of the tuning forks, they hum,
rather than tick. The problem is, these watches were originally designed
to run on a 1.35 volt mercury oxide cell (343) which is no longer
available. There is a 1.55v silver cell which will fit, but it can cause
some Accutrons to run very fast, and possibly even damage them. At least
one supplier sells modified cells with a component to drop the cell's
voltage to 1.35 volts. I think this is accomplished with a surface mount
type diode. Here's a thread on these cells in a watch discussion, with
pictures of the component added
http://bdwf.net/forum/showthread.php?t=75397 I would like to simply
insert an appropriate diode into the circuit of the watches as a one
time modification, after which I can use the much cheaper/readily
available silver cells. But, as I said, my electronic component
knowledge is late 70's vintage, so I'm not sure what component to add. I
know in general silicon diodes have a forward voltage drop on .7V,
germaniums, .3V, so I'm not sure how to produce .2V. A zener? A
Schottky? Anyone have any suggestions on what would lower the output of
the 1.55 volt cells to 1.35 volts, over the life of the cell? It would
have to be fairly small, about 1/2 the size of a 1/4 watt resistor, or
less.

TIA

The forward voltage drop is more a rule of thumb approximation than a
physical reality. A diode's current versus voltage graph is a continuous
exponential curve, with the actual forward voltage drop being a function
of current.

I'd have thought these watches would draw a pretty much constant
current, knowing which would allow a resistor to be used.

Sylvia.

 

[Geoffrey S. Mendelson]

D wrote:

I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage
Bulova Accutron wristwatches. These watches operate using a very basic
oscillator circuit which energizes a tuning fork via a pair of coils.
The tuning fork then drives the mechanical movement of the timepiece. A
basic description can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

Is there a hearing aid battery that will fit? They are listed as 1.4 volts,
but work fine in everything that uses them that I have heard of.

The only problem with them is that they need air to activate and once
opened dry out. In a watch, where the current draw is low, they would
probably last 3 to 6 months depending upon where you live.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Making your enemy reliant on software you support is the best revenge.

 

[mike]

Sylvia Else wrote:

On 6/07/2011 2:46 PM, D wrote:
I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage Bulova
Accutron wristwatches. These watches operate using a very basic
oscillator circuit which energizes a tuning fork via a pair of coils.
The tuning fork then drives the mechanical movement of the timepiece. A
basic description can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

These are very cool watches to the collector. They are stylistically
very much of their era, and because of the tuning forks, they hum,
rather than tick. The problem is, these watches were originally designed
to run on a 1.35 volt mercury oxide cell (343) which is no longer
available. There is a 1.55v silver cell which will fit, but it can cause
some Accutrons to run very fast, and possibly even damage them. At least
one supplier sells modified cells with a component to drop the cell's
voltage to 1.35 volts. I think this is accomplished with a surface mount
type diode. Here's a thread on these cells in a watch discussion, with
pictures of the component added
http://bdwf.net/forum/showthread.php?t=75397 I would like to simply
insert an appropriate diode into the circuit of the watches as a one
time modification, after which I can use the much cheaper/readily
available silver cells. But, as I said, my electronic component
knowledge is late 70's vintage, so I'm not sure what component to add. I
know in general silicon diodes have a forward voltage drop on .7V,
germaniums, .3V, so I'm not sure how to produce .2V. A zener? A
Schottky? Anyone have any suggestions on what would lower the output of
the 1.55 volt cells to 1.35 volts, over the life of the cell? It would
have to be fairly small, about 1/2 the size of a 1/4 watt resistor, or
less.

TIA

The forward voltage drop is more a rule of thumb approximation than a
physical reality. A diode's current versus voltage graph is a continuous
exponential curve, with the actual forward voltage drop being a function
of current.

I'd have thought these watches would draw a pretty much constant
current, knowing which would allow a resistor to be used.

Sylvia.




Might be interesting to know the startup current. Resistor may run it,

but starting may...or may not...be an issue. Don't forget to check it
over temperature. Yes, the arm is a quite stable environment, but
some people take their watch off occasionally.

For fun I stuck an old HP 5082 Schottky diode on the curve tracer.
200mV at 10uA.
I'd look at the spec sheets for modern SMT diodes and find one that
has the right voltage at the required current.

 

[Phil Allison]

"D"

I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage Bulova
Accutron wristwatches. These watches operate using a very basic oscillator
circuit which energizes a tuning fork via a pair of coils. The tuning fork
then drives the mechanical movement of the timepiece. A basic description
can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

These are very cool watches to the collector. They are stylistically very
much of their era, and because of the tuning forks, they hum, rather than
tick. The problem is, these watches were originally designed to run on a
1.35 volt mercury oxide cell (343) which is no longer available. There is
a 1.55v silver cell which will fit, but it can cause some Accutrons to run
very fast, and possibly even damage them. At least one supplier sells
modified cells with a component to drop the cell's voltage to 1.35 volts.
I think this is accomplished with a surface mount type diode. Here's a
thread on these cells in a watch discussion, with pictures of the
component added http://bdwf.net/forum/showthread.php?t=75397 I would like
to simply insert an appropriate diode into the circuit of the watches as a
one time modification, after which I can use the much cheaper/readily
available silver cells. But, as I said, my electronic component knowledge
is late 70's vintage, so I'm not sure what component to add. I know in
general silicon diodes have a forward voltage drop on .7V, germaniums,
.3V, so I'm not sure how to produce .2V. A zener? A Schottky? Anyone
have any suggestions on what would lower the output of the 1.55 volt cells
to 1.35 volts, over the life of the cell? It would have to be fairly
small, about 1/2 the size of a 1/4 watt resistor, or less.

** A Germanium diode has a 0.2 volts drop at low currents - eg sub 1mA.

SMD versions must be made by someone.

But do you know any voltage drop is really NEEDED ??




.... Phil

 

[William Sommerwerck]

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:97ip3pFp1rU1@mid.individual.net...

any voltage drop is really NEEDED?

Gee, Phil, I thought you were omniscient.

Though you'd think the mechanical nature of the Accutron's timekeeping
process would remove any interaction with the electronics, it's not so.

The user manual specifically states that the watch runs a bit fast with new
cells, until their initially slightly high voltage "settles in" to its
nominal value. Therefore, an Accutron will run fast with modern cells.

 

[Gareth Magennis]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:iv1k8c$aoh$2@dont-email.me...

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:97ip3pFp1rU1@mid.individual.net...

But do you know [whether] any voltage drop is really NEEDED?

Gee, Phil, I thought you were omniscient.

Though you'd think the mechanical nature of the Accutron's timekeeping
process would remove any interaction with the electronics, it's not so.

The user manual specifically states that the watch runs a bit fast with
new
cells, until their initially slightly high voltage "settles in" to its
nominal value. Therefore, an Accutron will run fast with modern cells.

What a crap design then.



Gareth.

 

[William Sommerwerck]

"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:vW%Qp.24258$Rw7.4612@newsfe28.ams2...

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:iv1k8c$aoh$2@dont-email.me...
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:97ip3pFp1rU1@mid.individual.net...

But do you know [whether] any voltage drop is really NEEDED?

Gee, Phil, I thought you were omniscient.

Though you'd think the mechanical nature of the Accutron's timekeeping
process would remove any interaction with the electronics, it's not so.

The user manual specifically states that the watch runs a bit fast with
new
cells, until their initially slightly high voltage "settles in" to its
nominal value. Therefore, an Accutron will run fast with modern cells.

What a crap design then.

How old are you?

The Accutron was designed 50 years ago. It uses a discrete circuit, which
seemed rather marvelously miniature at the time. And the Accutron was the
first wristwatch accurate to a minute a month -- quite an achievement for a
"crap" design.

 

[Reinhard Zwirner]

William Sommerwerck schrieb:

"Gareth Magennis" <sound.service@btconnect.com> wrote in message

[...]

What a crap design then.

How old are you?

The Accutron was designed 50 years ago. It uses a discrete circuit, which
seemed rather marvelously miniature at the time. And the Accutron was the
first wristwatch accurate to a minute a month -- quite an achievement for a
"crap" design.

FACK!

<http://members.iinet.net.au/~fotoplot/acc.htm>

Reinhard

 

[D]

On 7/6/2011 10:24 AM, William Sommerwerck wrote:
n Accutron will run fast with modern cells.

What a crap design then.

I'm afraid your ignorance is showing.

How old are you?

The Accutron was designed 50 years ago. It uses a discrete circuit, which
seemed rather marvelously miniature at the time. And the Accutron was the
first wristwatch accurate to a minute a month -- quite an achievement for a
"crap" design.

Thanks for that, Bill. The design is quite elegant, with the ruby
tipped tuning fork tines operating a micro-toothed wheel. That, the
fact that it hums rather than ticks, and that the sweep second hand
moves smoothly like an AC clock. Very unique concept. The design was
also used in a marine chronometer for navigating longitude, which
requires high accuracy
http://www.nmm.ac.uk/collections/explore/object.cfm?ID=ZAA0275. They
were also used in space, with the first Accutron timepiece sent up
aboard the Vanguard 1 satellite, which achieved orbit on March 17, 1958
(5 months before I was born). Very cool, but ya know, some people will
probably not get it, not to mention being rude enough to pointlessly
dismiss with the word "crap" something another person is sincerely
interested in.

Kids.

Here's more on the Accutron & space exploration, etc:
http://accutron.org/214/aerospace.htm

Here's a pic of one of my own Accutrons.
http://i1201.photobucket.com/albums/bb342/Yergen/AAlpha.jpg An "Alpha"
from 1961. Solid 14Kt gold. Now tell me that's not a cool looking
timepiece. ;-)

The effect of the silver cells varies from watch to watch, and there
have been cases of the movement being damaged by the extra voltage. I'd
prefer not to take that risk.

Dan

 

[D]

On 7/6/2011 3:28 PM, Meat Plow wrote:

I own a solid gold 1965 Accutron. My jeweler has a device he lays the
watch on, it listens to the mechanism and tells you how much the movement
is off time. He was able to adjust mine down all the way to about 30
seconds a month fast. I have no suggestion other than his suggestion that
there may be a retro-fit tuning fork out these somewhere. This was around
2004.

Do some research, you may be able to find a fix. I wouldn't screw with it
myself, that stuff is awful delicate.

Thanks MP. I've worked on a lot of watches, so that part doesn't
trouble me, I just want to find the ideal way of dropping the voltage.
It is possible to adjust the action of the tuning fork, which sounds
like what your jeweler did.

 

[Meat Plow]

On Tue, 05 Jul 2011 21:46:06 -0700, D wrote:

I am a watch collector & repairer. I also have a fair, though somewhat
dated, electronics background. I have several early '60's vintage
Bulova Accutron wristwatches. These watches operate using a very basic
oscillator circuit which energizes a tuning fork via a pair of coils.
The tuning fork then drives the mechanical movement of the timepiece. A
basic description can be found here:
http://www.timezone.com/library/horologium/horologium631672882451976629

These are very cool watches to the collector. They are stylistically
very much of their era, and because of the tuning forks, they hum,
rather than tick. The problem is, these watches were originally
designed to run on a 1.35 volt mercury oxide cell (343) which is no
longer available. There is a 1.55v silver cell which will fit, but it
can cause some Accutrons to run very fast, and possibly even damage
them. At least one supplier sells modified cells with a component to
drop the cell's voltage to 1.35 volts. I think this is accomplished
with a surface mount type diode. Here's a thread on these cells in a
watch discussion, with pictures of the component added
http://bdwf.net/forum/showthread.php?t=75397 I would like to simply
insert an appropriate diode into the circuit of the watches as a one
time modification, after which I can use the much cheaper/readily
available silver cells. But, as I said, my electronic component
knowledge is late 70's vintage, so I'm not sure what component to add. I
know in general silicon diodes have a forward voltage drop on .7V,
germaniums, .3V, so I'm not sure how to produce .2V. A zener? A
Schottky? Anyone have any suggestions on what would lower the output
of the 1.55 volt cells to 1.35 volts, over the life of the cell? It
would have to be fairly small, about 1/2 the size of a 1/4 watt
resistor, or less.

TIA

Dan

I own a solid gold 1965 Accutron. My jeweler has a device he lays the
watch on, it listens to the mechanism and tells you how much the movement
is off time. He was able to adjust mine down all the way to about 30
seconds a month fast. I have no suggestion other than his suggestion that
there may be a retro-fit tuning fork out these somewhere. This was around
2004.

Do some research, you may be able to find a fix. I wouldn't screw with it
myself, that stuff is awful delicate.



--
Live Fast Die Young, Leave A Pretty Corpse

 

[Arfa Daily]

"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:vW%Qp.24258$Rw7.4612@newsfe28.ams2...

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:iv1k8c$aoh$2@dont-email.me...
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:97ip3pFp1rU1@mid.individual.net...

But do you know [whether] any voltage drop is really NEEDED?

Gee, Phil, I thought you were omniscient.

Though you'd think the mechanical nature of the Accutron's timekeeping
process would remove any interaction with the electronics, it's not so.

The user manual specifically states that the watch runs a bit fast with
new
cells, until their initially slightly high voltage "settles in" to its
nominal value. Therefore, an Accutron will run fast with modern cells.




What a crap design then.



Gareth.

Makes a bit of a mockery of the name "Accutron" ...

Arfa

 

[Arfa Daily]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:iv25or$ukb$1@dont-email.me...

"Gareth Magennis" <sound.service@btconnect.com> wrote in message
news:vW%Qp.24258$Rw7.4612@newsfe28.ams2...
"William Sommerwerck" <grizzledgeezer@comcast.net> wrote in message
news:iv1k8c$aoh$2@dont-email.me...
"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:97ip3pFp1rU1@mid.individual.net...

But do you know [whether] any voltage drop is really NEEDED?

Gee, Phil, I thought you were omniscient.

Though you'd think the mechanical nature of the Accutron's timekeeping
process would remove any interaction with the electronics, it's not so.

The user manual specifically states that the watch runs a bit fast with
new
cells, until their initially slightly high voltage "settles in" to its
nominal value. Therefore, an Accutron will run fast with modern cells.

What a crap design then.

How old are you?

The Accutron was designed 50 years ago. It uses a discrete circuit, which
seemed rather marvelously miniature at the time. And the Accutron was the
first wristwatch accurate to a minute a month -- quite an achievement for
a
"crap" design.

But apparently not when you stick new batteries in, which I think is the
"crap" characteristic that Gareth was alluding to ...

Arfa

 

[Arfa Daily]

"D" <none@hotmail.com> wrote in message
news:4e14f93a$0$1730$c3e8da3$9b4ff22a@news.astraweb.com...

On 7/6/2011 10:24 AM, William Sommerwerck wrote:
n Accutron will run fast with modern cells.

What a crap design then.

I'm afraid your ignorance is showing.


How old are you?

The Accutron was designed 50 years ago. It uses a discrete circuit, which
seemed rather marvelously miniature at the time. And the Accutron was the
first wristwatch accurate to a minute a month -- quite an achievement for
a
"crap" design.



Thanks for that, Bill. The design is quite elegant, with the ruby tipped
tuning fork tines operating a micro-toothed wheel. That, the fact that it
hums rather than ticks, and that the sweep second hand moves smoothly like
an AC clock. Very unique concept. The design was also used in a marine
chronometer for navigating longitude, which requires high accuracy
http://www.nmm.ac.uk/collections/explore/object.cfm?ID=ZAA0275. They were
also used in space, with the first Accutron timepiece sent up aboard the
Vanguard 1 satellite, which achieved orbit on March 17, 1958 (5 months
before I was born). Very cool, but ya know, some people will probably not
get it, not to mention being rude enough to pointlessly dismiss with the
word "crap" something another person is sincerely interested in.

Kids.

Gareth is not a kid, and is in fact a highly experienced electronic service
engineer, as are many of us on here. I'm sure that he did not intend any
direct disrespect to you personally, as that is not generally his nature.
However, just because a design is 50 years old, and was 'elegant' in its
concept, that does not make it necessarily 'good', and by today's standards,
a design that purports to be an extremely accurate timepiece, but which runs
at an incorrect speed when the batteries are replaced, probably legitimately
counts as being 'crap'.

Arfa

 

[William Sommerwerck]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:FX7Rp.30076$Dk2.7423@newsfe04.ams2...

Gareth is not a kid, and is in fact a highly experienced electronic
service
engineer, as are many of us on here. I'm sure that he did not intend any
direct disrespect to you personally, as that is not generally his nature.
However, just because a design is 50 years old, and was 'elegant' in its
concept, that does not make it necessarily 'good', and by today's
standards,
a design that purports to be an extremely accurate timepiece, but which
runs
at an incorrect speed when the batteries are replaced, probably
legitimately
counts as being 'crap'.

You're an intelligent person, and I never expected to hear that from you.

Mercury cells start at a slightly higher voltage than their "running"
voltage. The Accutron was designed to give accurate timing over that long
period of more-or-less stable voltage.

You'd probably find that modern watches aren't much more-accurate than an
Accutron.

 

[Sylvia Else]

On 7/07/2011 11:40 AM, William Sommerwerck wrote:

"Arfa Daily"<arfa.daily@ntlworld.com> wrote in message
news:FX7Rp.30076$Dk2.7423@newsfe04.ams2...


Gareth is not a kid, and is in fact a highly experienced electronic
service
engineer, as are many of us on here. I'm sure that he did not intend any
direct disrespect to you personally, as that is not generally his nature.
However, just because a design is 50 years old, and was 'elegant' in its
concept, that does not make it necessarily 'good', and by today's
standards,
a design that purports to be an extremely accurate timepiece, but which
runs
at an incorrect speed when the batteries are replaced, probably
legitimately
counts as being 'crap'.

You're an intelligent person, and I never expected to hear that from you.

Mercury cells start at a slightly higher voltage than their "running"
voltage. The Accutron was designed to give accurate timing over that long
period of more-or-less stable voltage.

You'd probably find that modern watches aren't much more-accurate than an
Accutron.


I had an earlyish quartz watch that was achieving a minute a year, which

in practical terms meant it only had to be reset at daylight saving time
changes. It's true I've seen nothing that accurate since.

Sylvia.

 

[William Sommerwerck]

You'd probably find that modern watches aren't much more-accurate
than an Accutron.

I had an earlyish quartz watch that was achieving a minute a year, which
in practical terms meant it only had to be reset at daylight saving time
changes. It's true I've seen nothing that accurate since.

And I would be dishonest if I didn't admit my Casio Edifice watch is
accurate to within a few seconds a month.

 

[D]

On 7/6/2011 6:27 PM, Arfa Daily wrote:
elegant' in its concept, that does not make it necessarily 'good', and

by today's standards, a design that purports to be an extremely accurate
timepiece, but which runs at an incorrect speed when the batteries are
replaced, probably legitimately counts as being 'crap'.

Arfa

What was I thinking, valuing this gorgeous piece of
electronic/mechanical/engineering/jewelery-art, when I could just go to
Walmart and buy a plastic POS which will be more accurate?

I wonder why NASA didn't just do that, back in 1958???

And while we're discussing it, who are those fools who will fork over 6
figures+ for certain cars from the '20's & '30's, when a 2011 Kia
Something-Or-Other has a higher top speed and better gas mileage?

I have a "disposable" plastic POS I wear while biking, etc. It has its
place, and I'm glad to have it. But judging a 50 year old wristwatch
which was at the cutting edge of its discipline when it was made by the
TECHNICAL standards of today is pretty myopic, and misses the point
entirely.

Dan

 

[Meat Plow]

On Wed, 06 Jul 2011 17:11:57 -0700, D wrote:

On 7/6/2011 3:28 PM, Meat Plow wrote:


I own a solid gold 1965 Accutron. My jeweler has a device he lays the
watch on, it listens to the mechanism and tells you how much the
movement is off time. He was able to adjust mine down all the way to
about 30 seconds a month fast. I have no suggestion other than his
suggestion that there may be a retro-fit tuning fork out these
somewhere. This was around 2004.

Do some research, you may be able to find a fix. I wouldn't screw with
it myself, that stuff is awful delicate.




Thanks MP. I've worked on a lot of watches, so that part doesn't
trouble me, I just want to find the ideal way of dropping the voltage.
It is possible to adjust the action of the tuning fork, which sounds
like what your jeweler did.

Glad to offer an opinion for what it's worth. I took the watch, a gift
from my dad to the jeweler and was told immediately to not expect the same
time accuracy without a mercury battery. He was able to get it to +30
seconds a month which I could deal with. You might want to see if there
is a source for the original battery maybe from China that you could get
in a Chinese brand. I don't think they care much about the US
restrictions for mercury. I'm now wearing a gold Seiko Chronographer Date/
Time analog with three separate dials embedded into the watch face.
It's accurate to about one second a month. I don't need anything more
accurate than that. This watch is about 15 years old and takes a standard
lithium cell that lasts about 4 years.



--
Live Fast Die Young, Leave A Pretty Corpse