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guidovelasquez

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guidovelasquez last won the day on February 21

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About guidovelasquez

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    WRT Addict
  • Birthday 02/05/1965

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    Guatemala
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    Electrónica, Fotografía, Montañismo, Cometas

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  1. http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&2&2uswk&Baumgartner_844
  2. 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.
  3. I like a statement that Spanish says: "We are all ignorant. What happens is that some of us ignore some things and others ignore others."
  4. If you realize the piezoelectrics here ARE NOT SOUND SENSORS, they are sound producers. In the 1970s when quartz watches arrived, I had my first contact with piezoelectric discs. And they were always buzers. Over time I realized that they can be used as vibration sensors.
  5. Completely agree. Actually although it is a microphone, technically it is a vibration sensor. It is difficult to pick up the waves that travel in the air from the sound of a watch. The best way to avoid background noise in a work room will be an efficient vibration sensor that captures these from the closest to their source.
  6. I thought the same at first about the green bimorph. I thought it was "holy grail". Unfortunately in my country there is no way to find it and even impossible to request it overseas, since they do not send it. Thanks to Ryder @24h, who sent it to Guatemala, I realized that it is no better than a piezoelectric disc. Go ahead .... It is one of the reasons for our existence: "ask ourselves questions and seek the answers .... seek the truth"
  7. Take a look at this place, you will probably find timely information. https://www.etimer.net/
  8. Here is an example of a recording with a piezo disk and a transistor. There is no preamp circuit (although actually the transistor + resistor is). It is sufficient for most of the watches that you will examine. And also the screenshot of wos. Note that none of the preamp has been added.20 seg. Transistor Clean.wav
  9. The vibration levels are extremely low. It is the reason why these timegrapher devices need a pre-amplifier. But what I am sure of is that a piezoelectric disk + a transistor will be enough for what you need.
  10. I don't know who James is. But if he explains, I can help. I already removed the bimorph sensor from the metal part. It's in good condition. And I must take care of it because nowhere in my country do they sell. It's the one Ryder @24h shared with me. There is one more thing I can assure you. THE BIMORPH SENSOR WILL NOT WORK WITHOUT A PREAMPLIFIER. Preamp is required. But there is a simple solution. is to add a transistor and a resistor only. https://bit.ly/3s2W0jQ https://bit.ly/2NzhqGn
  11. He's right I didn't know. I will have to repeat the test with that information. Although I do not think it significantly modifies the results. Regarding your project, I can assure you that the best thing will be to place a glued piezoelectric disk instead of the crystal.
  12. Good job @luiazazrambo you have done your homework. I see that you have thoroughly read the blog. I will try to explain as best I can. The bimorph sensor is a piezo electric and is not sensitive to humidity, not to the degree of the old salt-based crystals used by the timegraphers of the 40s 50s 60s 70s. But from my experience, they are not that sensitive. The glue: It can be a good quality epoxy resin. The idea is that it solidifies very well, as it is the passage of vibratory waves towards the crystal. About the coils. Some stands for examining watches, (not the case of yours
  13. https://es.wikipedia.org/wiki/2N3904 I think that the 3904 is the most suitable option. As I have seen, it can even be found in many devices, if it were not possible to get it new in a store.
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