D. I. Y. Watch Timing Machine.

[guidovelasquez]

2 hours ago, LittleWatchShop said:

9 minutes ago, 24h said:

I did not have any decent piezos in my lab (hard to believe...I have everything else!), so I ordered some.

you can get maybe in small toys or musical cards. they also have quartz watches with an hour indicator. They are on the back cover of the watch.

 

[LittleWatchShop]

32 minutes ago, 24h said:

What diameter did you order?

27mm.  Incredibly sensitive.

[LittleWatchShop]

13 minutes ago, guidovelasquez said:

or musical cards

Yeah, something got in my head once and I bought a box of 50 Sonalert beepers.  They have three terminals (the extra is a feedback terminal) so you can make oscillators.  I tore one apart and stole the piezo.  It did not work well at all, and I think the problem was that it was pretty thick...perhaps to get a lot of output amplitude...dunno.

[24h]

On 2/28/2021 at 2:05 PM, LittleWatchShop said:

27mm.  Incredibly sensitive.

I had way better results with 12mm vs 27mm.
I keep meaning to purchase some 10mm or 7mm piezo discs to compare the difference.

[LittleWatchShop]

1 hour ago, 24h said:

I had way better results with 12mm vs 27mm.
I keep meaning to purchase some 10mm or 7mm piezo discs to compare the difference.

Still perfecting the final product...are the smaller ones 'more' sensitive?

[LittleWatchShop]

My preamp...as of today

[LittleWatchShop]

This is my sensor setup for prototype purposes

[guidovelasquez]

2 hours ago, LittleWatchShop said:

My preamp...as of today

We would like to listen to an audio file.

[LittleWatchShop]

8 hours ago, guidovelasquez said:

We would like to listen to an audio file.

OK, I will have to attenuate the output to line levels and then capture it with my Tascam recorder.  Give me a day or so...distracted by other shiny objects!

[luiazazrambo]

On 2/28/2021 at 7:37 PM, LittleWatchShop said:

This may be a "tired" thread, but I still keep playing around with my sensor.

Not "tired". Keep it coming. Thank you for sharing.

[24h]

21 hours ago, LittleWatchShop said:

Still perfecting the final product...are the smaller ones 'more' sensitive?

Smaller ones seem to produce a "cleaner" and more accurate sound. Any size will work perfectly with TG or Watch-O-Scope but my goal was to get the best sound. As for the question of whether it's more sensitive? I'm not sure! I think the main takeaway from my testing is that if the disk is larger than the diameter of the surface that's making contact with the watch crown, you will pick up additional (unwanted) noise.

The 'pin' on my timing stand is ~6mm so I'd want to have something closer than that rather than overhang it with a 27mm disk.

Here are several recordings that compare 12mm and 27mm from two different watches. The pre-amp, and high-pass filter are the same on all files. I have not yet tried the method that Guido uses with a resistor and transistor. I think it will include even less static/noise.

https://mega.nz/file/dtYHXQqK#0cVkxw02t1NSl4VE3B0tn4pOoGLmTn3NAo5_Xx162N0

Edited March 2, 2021 by 24h

[LittleWatchShop]

58 minutes ago, 24h said:

Smaller ones seem to produce a "cleaner" and more accurate sound. Any size will work perfectly with TG or Watch-O-Scope but my goal was to get the best sound. As for the question of whether it's more sensitive? I'm not sure! I think the main takeaway from my testing is that if the disk is larger than the diameter of the surface that's making contact with the watch crown, you will pick up additional (unwanted) noise.

The 'pin' on my timing stand is ~6mm so I'd want to have something closer than that rather than overhang it with a 27mm disk.

Here are several recordings that compare 12mm and 27mm from two different watches. The pre-amp, and high-pass filter are the same on all files. I have not yet tried the method that Guido uses with a resistor and transistor. I think it will include even less static/noise.

https://mega.nz/file/dtYHXQqK#0cVkxw02t1NSl4VE3B0tn4pOoGLmTn3NAo5_Xx162N0

I listened to them...sounds like the 27mm is saturating...at any rate, it is a greater amplitude--what I would expect with the larger vs. smaller.   I am not using the timing software, just looking at the output on my oscilloscope.  Can you show the waveforms for these to cases?  I think watch-o-scope will do that.

Another thing that one would expect.  When I modify the way I mount the piezo, I can change the sensitivity.  Less cantilever...lower amplitude.  This makes sense to me anyway.

Interesting stuff.

I will add an emitter follower and attenuate the output so that I can record it with my Tascam...on another day.

 

[timwatchcrazy]

On 3/7/2018 at 4:14 AM, matabog said:

So I played a bit in Solidworks, and this is what I got. A friend of mine helped me with the 3D printing.

 

sup_2.STL 374.4 kB · 28 downloads

mic 2.STL 191.98 kB · 24 downloads

pesa.STL 311.51 kB · 23 downloads

sup_1.STL 314.24 kB · 22 downloads

 

the editables:

 

mic 2.SLDPRT 169.19 kB · 21 downloads

pesa.SLDPRT 226.88 kB · 14 downloads

sup_1.SLDPRT 234.39 kB · 15 downloads

sup_2.SLDPRT 178.4 kB · 15 downloads

ansamblu2.SLDASM 292.61 kB · 14 downloads

 

 

[timwatchcrazy]

On 3/7/2018 at 4:14 AM, matabog said:

So I played a bit in Solidworks, and this is what I got. A friend of mine helped me with the 3D printing.

 

sup_2.STL 374.4 kB · 28 downloads

mic 2.STL 191.98 kB · 24 downloads

pesa.STL 311.51 kB · 23 downloads

sup_1.STL 314.24 kB · 22 downloads

 

the editables:

 

mic 2.SLDPRT 169.19 kB · 21 downloads

pesa.SLDPRT 226.88 kB · 14 downloads

sup_1.SLDPRT 234.39 kB · 15 downloads

sup_2.SLDPRT 178.4 kB · 15 downloads

ansamblu2.SLDASM 292.61 kB · 14 downloads

 

Thank you for sharing this Matablog. Nice files, I did use 4- #10 wood screws to hold the frame and a 1/4" X 20 X 4.5" screw for the watch holder due to not being able to find a long  M6 screw. I still need to add the sensor to it. Here are some pictures of what I made. I also made a thumb screw for this as a M6 (file added Below) but ended up taping it out for the 1/4" X 20. 

M6 THUMB SCREW.stl

[CWRNH]

So I finally built the amp.  It doesn't work.  I did something wrong.  In over my head I guess.  No Idea what the problem is.  No output.  U5 gets warm. 

[LittleWatchShop]

Measure the voltages at the pins of the LT1114 and post them here.  Measure with respect to the negative side of the battery.

[wlysenko]

CWRNH: Nothing I make works the first time. Time to begin troubleshooting. First thing to do is measure voltages at pins 4 and 7 on all ICs to see if they are getting the proper power. If you have a signal generator, attach it to the input and look at the output of the first stage, preferably with an oscilloscope, but a voltmeter will work. U5 getting warm is not a good sign. For me, that often means a ruined IC because of a wiring error.

LittleWatchShop: Why do you want to measure voltage with respect to the negative battery terminal and not ground?

[guidovelasquez]

2 hours ago, CWRNH said:

I did something wrong.

Don't worry T. A. Edison took a long time to find the results for the incandescent light bulb.

[JohnR725]

12 minutes ago, wlysenko said:

Why do you want to measure voltage with respect to the negative battery terminal and not ground?

I'm sure that LittleWatchShop Will be around a little bit give a better answer than mine. The problem we have is that he's using a virtual ground. That's because there's only one 9 V battery it probably would've been better used two 9 V batteries and have a real ground. 

[LittleWatchShop]

32 minutes ago, JohnR725 said:

I'm sure that LittleWatchShop Will be around a little bit give a better answer than mine. The problem we have is that he's using a virtual ground. That's because there's only one 9 V battery it probably would've been better used two 9 V batteries and have a real ground. 

@JohnR725gets to my reasoning...re virtual ground.  I want to measure with respect to a known potential.  The virtual ground circuit may be the issue. 

Edited March 14, 2021 by LittleWatchShop

[CWRNH]

2 hours ago, LittleWatchShop said:

Measure the voltages at the pins of the LT1114 and post them here.  Measure with respect to the negative side of the battery.

When testing pins 7, Probes = Negative on Batt - , and Positive on pin 7

U5 = 8.99v, U2= 7v, U3= 7v, U4= 7V

When testing pins 4, Probes = Negative on Batt - , and Positive on pin 4

U5 = 8.99v, U2= 8.99v, U3= 8.99v, U4= 8.99v

9v exactly for input.

[CWRNH]

1 hour ago, wlysenko said:

CWRNH: Nothing I make works the first time. Time to begin troubleshooting. First thing to do is measure voltages at pins 4 and 7 on all ICs to see if they are getting the proper power. If you have a signal generator, attach it to the input and look at the output of the first stage, preferably with an oscilloscope, but a voltmeter will work. U5 getting warm is not a good sign. For me, that often means a ruined IC because of a wiring error.

LittleWatchShop: Why do you want to measure voltage with respect to the negative battery terminal and not ground?

I can see the signal on the scope coming from the first IC pin 6 with power off.   Same as input signal, no change, which makes sense I guess because it is a buffer.  After that nothing on the rest.  I must have the floating ground wrong.  The only change I made from the original schematic was adding c19

[CWRNH]

I checked all the values of all the components before I installed them....  Twice.. LOL

[LittleWatchShop]

1 minute ago, CWRNH said:

I checked all the values of all the components before I installed them

But you did not give me ALL of the voltages on the pins of U5

Also the voltages on the virtual ground U1

Edited March 14, 2021 by LittleWatchShop

[CWRNH]

2 minutes ago, CWRNH said:

I can see the signal on the scope coming from the first IC pin 6 with power off.   Same as input signal, no change, which makes sense I guess because it is a buffer.  After that nothing on the rest.  I must have the floating ground wrong.  The only change I made from the original schematic was adding c19

I do have a couple signal generators and a few oscilloscopes.  I used the mic as my input though