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Bulova Accutron

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I've had similar issues with getting a 1.35v mercury replacement battery for a vintage 1970 camera. I suspect that the battery for a watch would need to be packaged smaller. I don't know if there is anything of use in this pdf. I believe there are still mercury batteries coming out of Russia. I also know there are some replacements made using a diode like this one.

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On 7/16/2022 at 5:36 PM, PSquared said:

It makes me wonder if a resistor

I was hoping To post a really good picture of the insides of the Accucell. As I disassembled one the other day but I miss placed The tiny little circuit board with the whatever it is

For my view on this I like the fact that you can actually phase the watch to work with the silver cell. That means no modification of the circuit is required and it does seem to work. So for me that's what I intend on doing.

Then the tuning fork circuitry is clever. In order to prevent over indexing when the watches impacted or something causes extra low vibration to transmit to tuning fork the circuitry actually drops its drive power that way it doesn't over index. That means our circuitry is not consistent on its current drawn. Plus they can a modification you do it does require modification to the watch. Then as he also noted there were variations in the circuitry and not just on the 218 214 has some variations I don't know how that's going to change things.

Probably a much more clever thing to do would be to modify the coils and circuits. There is somebody out there who rewinds 214 coils I don't know if he's doing the other ones suggest design a new circuitry work with a silver cell how hard could that be?

Or Just phase at first silver cell and be done with it so far that's worked well for me sometimes you have to go back and tweak it if it's not quite right but it seems to be so far.



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Hi  Hector,

I agree - too expensive / forces a reduced capacity battery - but if the .2V drop the diode provides makes phasing easier / more likely to succeed - then it seems it makes sense to put it inside the watch - as the other poster did.

My only additional points in my post was that the specs for the part used reveal that the voltage reduction is not really .2V and may never be more then ~ .140 mv. - - - this is better then a lot of other Schottky diodes I looked at. I also questioned if a resistor wouldn't work well.


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