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I'd prefer not get them from a file-sharing site, as many of these install malware. The fact that it didn't work for ligangyi suggests that you may have the permissions set on the attachments such that only you can access them. I'll send you a PM and give you my e-mail address and you can mail them to me.

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I received the samples you e-mailed me, and they sound fine. The noise levels are certainly not a problem for analysis of the signals. Most of that noise comes from the amplifier itself. Any resistor produces noise proportional to its resistance, so the noise produced by the earliest stages of amplification becomes amplified by the later stages.

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You can download the File from the download site if you pay attention and perhaps are lucky and depending on how your browser handles files for downloading.  So unchecked the box that you want to install the download manager. Then I ignored the warning that I needed to install another plug-in which you don't. Two separate download buttons the gray button actually downloads the zipped file. The black button attempts to download the zipped file disguised as the download manager In other words a exe Which is definitely not what you want.

 

I give you shielded the pickup it would help quite a bit for the background White noise.

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  • 2 weeks later...

The Watch-O-Scope software is now available for general downloading. This is version 1.0 Beta 2. All features are available for a period of 60 days from first use or from release of the final version, whichever is later. After the evaluation period, it reverts to a "Lite" mode where some of the more advanced features useful to professional watchmakers are disabled.

 

http://www.watchoscope.com

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This is really nice. I read the whole thread with great interest, since I still do not own a timing machine, and I only can find chinese branded ones on eBay for the budget I can dedicate to it. I used until now my cheapo-tablet with an android app, and eve if it is not extremely precise, it gets the job done (at least for a hobby watchmaker like myself). I was aware right from the start that the mic on this tablet was not the "best", so I was looking at a DIY solution, and found this project here. I do not posses the necessary soldering skills to build it, though, after going through all the pics in this thread, so I am looking to get the "pro" version, whenever you make it available.

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Hello!
First of all, congratulations on the Beta version!
Second, I compared the noise from the first amplifier with the one from the second, and I think that there is an improvement (on the second one). What I did was I short circuited the piezo and what was left was the noise (@JohnR725: this is why I doubt using a shielded cable would improve the signal to noise ratio, though the downside would be that it would make the cable stiffer and so the sensor would pick up more ambient noise (table movement, etc). Indeed if I use the charger on the laptop, the noise increases (with the mains noise - 50Hz and some harmonics) but otherwise it is ok.
Third, and most important, I tried the application and it works great! I would call it "plug and play". The best thing about it, in my opinion, is the long term analysis. It's also very nice it shows you the waveform also - I couldn't manually set the threshold, but also I didn't read the manual (RTFM :)) I don't know what to say about the sound card clock jitter compensation, but I think that on the long term analysis it doesn't matter too much.
Here are some pictures with a 2893-2 base movement (only the train and the escapement) and its behaviour in the app. Take into consideration that it is an uncleaned donor-intended movement:
the waveform:
the short-term behaviour:
the long term behaviour ( for a short term :) ):

 

Again, a big Thank you, Stefan, and Great Work!

 

Bogdan

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Glad to hear it's working for you!

 

To manually set the threshold, you have to enable that option in the settings window.

 

As far as sound card rate goes, it's not jitter that is being corrected for, but the overall average rate of the card. You really should calibrate Watch-O-Scope by manually setting the rate to 3600, and putting a known-to-be-reasonably-accurate quartz watch on the microphone for a few minutes. Any reported rate error can then be corrected in the settings window.

 

Stefan

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After seeing Mark's great video tour of his new workshop, I am now contemplating dusting off an old Windows laptop to use as a timegrapher, just need to find out from Mark the wiring for the microphone now, and how it connects up to the laptop.

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So install the software on a netbook which has a minor problem of the screen is too small and toolbar on the bottom covers up the very bottom of the screen. I think there’s a way of making the toolbar disappear I just haven’t had time to look into that. So left everything on default other than changing the lift angle for the particular watch I was timing. So outstanding that the software is out to play with.

 

Then there have been other Windows-based timing machines in the past none of which worked very well so I made this amplifier to play with the other software. So this is a dual op amp design with a little bit of filtering.

post-673-0-95631200-1427366014_thumb.jpg

post-673-0-34102100-1427366015_thumb.jpg

post-673-0-83581800-1427366015_thumb.jpg

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Thanks for sharing your experiences John.

 

As far as the window size goes, I specifically made it 1024x600 so as to fit on common netbooks screens, but I had forgotten that not everyone runs their netbooks with the taskbar hidden (I do just because there's so little screen real estate to begin with).

 

Is that Windows 8? If so, you're the first person (that I know of) to try my program on Windows 8. I figured it would work, since the program doesn't do anything non-Microsoft-kosher, but it's good to see confirmation.

 

Here's how you hide the taskbar in Windows 8:

  1. Open Taskbar and Start Menu Properties by clicking the Start button, clicking Control Panel, clicking Appearance and Personalization, and then clicking Taskbar and Start Menu.
  2. Clear the Lock the taskbar check box.
  3. Select the Auto-hide the taskbar check box.

That amplifier looks like it might be similar to my original dual op-amp version in terms of general architecture (mine was certainly not the first amplifier to be designed in that way).

Edited by svorkoetter
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@JohnR725: Hello! Could you please share the schematics? I see you have a very good signal-to-noise ratio in your watch-o-scope waveform.

 

It might also be because you have a very strong-ticking watch :)

 

Thank you!

Bogdan

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Another update. Both the microphone and amplifier construction articles are now complete. They're still a little rough, and I'll tweak them as time permits. If you see anything glaringly wrong or confusing (especially those of you that have already built the amplifier from my earlier posts), please let me know.

 

Building a Microphone Stand

 

Building a Microphone Amplifier

 

Stefan

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