A teardown of piezoelectric buzzer from Electronupdate:
An assembly commonly used on fire, burglar and similar alarm systems.
Based around a piezoelectric disk coupled to a plastic cylinder with a hole on the end (used to amplify the sound).
The controller appears to use a rom-based look up table to generate the sounds
The pattern right below the array almost looks like a series of digital wave forms. I think this is strong evidence of an address decoder.. I presume there is a decoder below each of the columns which actives if the pattern matchs.
Teardown and analysis of Deepace KC901V 6.8GHz handheld network analyzer from the The Signal Path:
In this episode Shahriar reviews the Deepace KC901V 6.8GHz handheld network analyzer. This battery-powered instrument is an RF multi-instrument integrating VNA, spectrum analyzer, field strength meter, and a low-frequency signal generator. It can also perform signal port vector measurement and 2-ports simple vector network analyzing (S11, S21).
I’ve gotten a lot of questions on the blog about the new version of the MHS5200A function generators available on eBay. Viewer Tolga was kind enough to send one in to me to review and tear down. Although some improvements have been made over the older models, there are some concerning issues with these new models too!
Teardown: A look at the Datum/Symmetricom 8040 Rubidium frequency standard
The 8040 used an LPRO 101 (low profile Rubidium oscillator) oscillator. Interestingly, there is a note written on the top of the LPRO case: “vibration test may have magnetized cover”. As you may know, Rubidium standards’s accuracy is very sensitive to external magnetic field. But it shouldn’t be an issue for me as the drift caused by magnetism is usually in the sub milli-Hertz range and even the most sensitive frequency counter in my lab won’t be able to pick up this minute drift.