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I managed to get my hands on a bimorph sensors and I just put it in the old circuit (the one with the piezo sensor).
What I can say is that I was expecting more. There is a slight improvement but I didn't have the time to play with it.
 
Stefan, did you get to try them?

 

Mine arrived a few days ago, but I haven't yet had a chance to experiment with them. Did you plug yours directly into the computer, or use the amplifier?

 

I have been thinking about these sensors, and the various pictures of watch microphones that I've seen. I think that how they are attached is important, and that improper attachment could make them no better than a regular piezo.

 

I am planning to experiment with these sensors over the holidays, perhaps by modifying an off-the-shelf case holder. If that works out, it will make the watch microphone much easier to build.

 

Unrelated to the sensors, I have some additional findings with respect to electromagnetic interference from dimmed lights (especially LEDs). I was testing a watch a few days ago, and forgot to turned off the LED lights in the room, and was surprised to find that there was no interference.

 

And then it struck me! The watch I was testing had a leather strap, but all the ones I was getting interference from had metal bracelets. Of course! The watch is in both physical and electrical contact with the bare metal disk of the piezo. A watch with a metal bracelet would make a very effective antenna, picking up any electromagnetic signals in the area and feeding them directly into the ground side of the amplifier, thus negating the effects of any shielding. This makes me think that some sort of insulator is needed between the watch and the piezo disk, perhaps a thin layer of some sort of very hard plastic (soft plastic would act as a sound insulator).

 

On another note, I've also been working on some improvements to the software, specifically in the area of beat error determination. Right now, if one has a somewhat noisy watch, where the ticks occasionally seem to occur too early for reasons other than beat error, this throws off the beat error reading. My improved algorithm is very good at ignoring these spurious sounds, resulting in a much more realistic and steady beat error display.

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I just replaced the piezo sensor with the bimorph one (my amplifier has plugs for in and out). I put the watch crown directly on the sensor, which is the best case scenario, I think. Anything between them would attenuate the "mechanical" sound.

 

About the insulation, I think the bimorph sensor is indeed insulated, meaning the watch will not have electrical contact with the amplifier ground.

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I've also been working on some improvements to the software, specifically in the area of beat error determination. Right now, if one has a somewhat noisy watch, where the ticks occasionally seem to occur too early for reasons other than beat error, this throws off the beat error reading. My improved algorithm is very good at ignoring these spurious sounds, resulting in a much more realistic and steady beat error display.

 

Here's an example:

 

post-140-0-81029500-1450801016_thumb.png

 

With the previous version of Watch-O-Scope, this would have given a beat error reading of around 0.6ms, whereas you can clearly see that the new reading of 0.2ms looks about right (the ticks on the left hand edge are 1ms apart).

 

I've applied a similar change to the amplitude averaging (the amplitude shown here is probably too high, because I don't know what the lift angle is for the Sea-Gull ST-19 that I was testing, and I doubt that the value of 44 that I came across somewhere is correct).

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  • 3 weeks later...

No news yet. I thought I'd have time to test them over the holidays, but I didn't. Hopefully soon! I also want to release an update to the software soon (as described a few posts back).

 

One thing I did find is that with several of my watches, the existing piezo mic works much better with the case against the piezo, than it does with the crown against the piezo. This is contrary to everything I've read about traditional timing machines, where the vibrations are picked up through the crown.

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  • 2 weeks later...

Check the thread for various amps people have tried. Some time I soon I plan to describe an easier-to-build amp.

 

Yes, it can definitely be used as a professional tool. It's every bit as good as the Chinese timegraphers (assuming you have a suitable microphone and amplifier), and as full-featured as some very expensive Swiss ones.

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  • 4 weeks later...
Hello!

So I played a little with the bimorph element (BM15015-06HC). IMHO it gives the same response. The advantage (or disadvantage) is that it is small.

In the Timegrapher 1000, for instance, it is stuck to a metal plate on which the watch crown rests.

The problem is that one looses signal strength by doing that - the key is to put the watch stem in direct contact with the sensor and then against a hard surface after that - so I have to think about a new way to design the watch holder ... ... ...  but I don't know if it makes sense or not to do that - I have a design that already works...

 

If anyone has anyother ideas, please share them.

 

Bogdan

Edited by matabog
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  • 1 month later...

I just want to update everyone about a problem that some of you have encountered, whereby Watch-O-Scope would crash when starting a timing test. I was never able to reproduce this on any of the dozen or so machines I have access to, but with the help of another user, I was finally able to get to the bottom of this. It turns out that the problem only happened if Windows was configured to use larger than "Normal" fonts. Version 1.2 of Watch-O-Scope fixes this problem, and is now available for download from watchoscope.com

Besides fixing the aforementioned bug, this new version also produces much more stable beat error and amplitude readings, being able to ignore the occasional tick that mis-registers. For example, if you have a watch with a beat error of 0.1ms, but 1 in 5 ticks misregister due to a low signal to noise ratio, you might have gotten a reported beat error much higher than this, even though the dots on the display clearly show a very small beat error. The new version can deal with this, and will correctly report the 0.1ms beat error. Likewise for amplitude.

Finally, I've been having general trouble with my Windows 7 laptop lately, and I was also getting recurring Windows 10 upgrade notices from Microsoft (despite having uninstalled and hidden the "update" that causes these). So I finally upgraded my laptop .... to Lubuntu 15.10 (a version of Linux). I'm happy to report that Watch-O-Scope works flawlessly under WINE, a Windows compatibility layer (WINE Is Not an Emulator, which means you don't need a copy of Windows to use it) available for both Linux and OS/X.

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  • 1 month later...

Hello Stefan! Thank you very much for version 1.2 Watch-O-Scope. Although as I'm concerned the previous version was already quite stable, version 1.2 is excellent.

W-O-S  1.2.PNG


One of the most versatile features that positions almost on all Timing machiene software watches is "Annotate" and "Generate Report". Allows the study of watch performance in different positions and also create a log report to compare results in different positions. Great!

Report pdf.png

Here is a screen shot of report in pdf.


  Although virtually no something to improve, I wish to propose to integrate a volume control sound input device that can be manipulated from the screen "control threshold". That would help to obtain an optimal signal level. Is it too much to ask?

W-O-S  1.2 Wave Form.PNG

A very informative view of the waveform.

W-O-S  1.2 Long Term Test.PNG

"Long Term" feature. Excellent for long periods of study up a watch.


  Thank you. Stefan good work.

Guido

 

 

Edited by guidovelasquez
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Recently joined to this forum and just find this thread. First, let me thank You for this excellent software!

My setup is a simple watch case holder with a piezo directly connected to my laptop. No amplification at all. There is a nice application called "Equalizer APO" where i can set the desired filters and gain to get excellent signal/noise ratio without preamp.

You can see my settings for the ideal equalization. BTW, this one is a really silent watch :)

20160523_090236[1].jpeg

Untitled.jpg

 

 

 

 

 

 

 

Edited by szbalogh
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  • 3 weeks later...

Just want to report that my cheap chinese watch was adjusted using Watch-O-Scope to my daily routine. Although it has ~15 sec max difference in the different positions, it is really accurate in the average. 12H down and crown down positions were considered with higher weight. 

Thank You again for this awsome software!

2016-06-09 06.50.06.jpeg

 

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On 5/23/2016 at 0:15 AM, szbalogh said:

Recently joined to this forum and just find this thread. First, let me thank You for this excellent software!

My setup is a simple watch case holder with a piezo directly connected to my laptop. No amplification at all. There is a nice application called "Equalizer APO" where i can set the desired filters and gain to get excellent signal/noise ratio without preamp.

You can see my settings for the ideal equalization. BTW, this one is a really silent watch :)

 

Nice! I'm going to try Equalizer APO with the mic from my timegrapher. I've had most of the components to make an amp for a couple of months, but I haven't gotten around to making it. This could give me a good shortcut. Thanks!

Edited by Don
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  • 3 weeks later...
On 6/11/2016 at 0:22 AM, Don said:

Nice! I'm going to try Equalizer APO with the mic from my timegrapher. I've had most of the components to make an amp for a couple of months, but I haven't gotten around to making it. This could give me a good shortcut. Thanks!

I have had a look at APO, while waiting form the parts to build my amp, all i receive is a error from Watch O Scope 

 

"Unable to open audio input device, the specified format is not supported or cannot be translated, use the capabilities function to determine the supported formats"

 

I am struggling to see what the capabilities function is. 

 

What if any specific settings have been successful with APO ?

 

Many Thanks 

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In the case of an audio device error, Watch-O-Scope just displays the message that is given to it by the device driver. In this case, I the "device driver" is actually APO, pretending to be a device. So, the "capabilities function" is something within APO, not Watch-O-Scope.

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  • 3 weeks later...

Any pointers on recreating your original circuit diagram onto a Strip board, i have recreated the power section of the amp but i am getting 9v where i should be getting vgnd 3.6v.  from what i can see Pin4 and Pin11 on the TL074 pretty much wire straight to the battery with the other components around it, sorry if this is a daft question i am getting slightly confused with the assembly of the circuit. I am a complete novice with electronics   

Just to confirm, does the Battery negative run on the same ground line as R9,C8,C9,C10 and C11 ? 

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I assume, from your mention of R9, C8, etc., that you're referring to the version described here, http://www.watchoscope.com/amplifier.html, since the original version (first few pages of this topic) doesn't have an R9, C8, etc.

Yes, one side of R9, C8, C9, C10, C11, pin 11 of the chip, and the battery negative are all connected together. If you're getting 9V on pin 1 (and 5, 10, and 12) of the chip, then you've likely made a wiring error.

Can you post a picture, front and back? That will make it easier to debug.

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You've misidentified the pins on the IC. Pin 1 is the lower leftmost pin in the first photo, and pin 14 is the upper left most. Thus you've got +9V connected to pin 11, -9V connected to pin 4, and the junction of R8, R9, C8, and C9 connected to pin 12. That of course explains why it's not working at the moment. Unfortunately, you've probably also destroyed the chip, since the power is hooked up backwards.

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