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Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
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17th Feb 2021, 2:05 am | #1 |
Heptode
Join Date: May 2005
Location: Adelaide, South Australia
Posts: 541
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DIY Watch Timegrapher
After inheriting my late fathers watches (none of which worked) I've been dabbling in amateur watchmaking with a bit of success - part of this is the actual setup of the time keeping, for which a timegrapher is used. I was loathe to buy a basic Chinese made machine reasoning that once I get the watches serviced and setup I probably wouldn't need it for another 5 or 6 yrs (average service interval). I came across a watch repair forum where members were discussing the use of freeware called Watch o scope, when combined with a microphone the timing could then be adjusted with good accuracy. The author of Watch o scope has put a lot of work into the software and I applaud them for their work - it is a fantastic effort, there is a paid version with extra features, however is all one wants is to adjust the timing the freeware version is good enough.
I copied the basic mechanical setup of commercial machines making the parts with my 3d printer, a piezo buzzer was taken apart for the piezo microphone element and a basic amp was made on vero board with the good old TL07X series of opamps, the circuit is nothing special I just copied what others on the forum had done with the exception of the single supply setup, I'm not a fan of operating opamps from a single 9v battery, it is getting close to the lower limit of the supply voltage and for me at least I dislike going to use something only to find the battery has run down, so I opted for an external 15V plugpack and split this into plus and minus 7v rails with resistor/capacitor/zener diode setup. |
11th Apr 2021, 1:13 pm | #2 |
Triode
Join Date: Jun 2012
Location: Dublin, Ireland.
Posts: 37
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Re: DIY Watch Timegrapher
Nice! I built one of these myself a few years ago when I bought some old Russian Poljot and Strela watches. I used THIS circuit for the pre-amp
It works very well and comes in very useful when servicing/regulating these watches. I had the same thought as you. I wasn't prepared to buy a Timegrapher when it's something I would use very occasionally. I made a separate clamp and preamp. I like the way yours is all one unit. The spring mechanism is great also! I also need to change my design so it has adjustable pegs for different watch case/movement sizes. |
11th Apr 2021, 2:28 pm | #3 |
Guest
Posts: n/a
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Re: DIY Watch Timegrapher
That (the soundcard route) is so bloomin' obvious that I missed it, thank you very much. Recently I have been given a 1900(ish) carriage clock by a friend* and it is hopeless on timekeeping, having a quick analysis will help no end. I want to restore it to resplendent glory for his daughter and give it back to the family.
*He had a stroke a couple of years ago, only language communication seems to be affected, reading, writing and speaking. Graphics and gestures are fine, makes me think "What if I lost that?". Social distancing doesn't help, but after a few minutes of conversation we are in a swing. |