Pete posted an article taking a closer look at Maxim’s DS3231 real-time clock:
Fortunately, Maxim also offers the DS3231, which is advertised as an “Extremely Accurate I2C-Integrated RTC/TCXO/Crystal”. This chip has the 32kHz crystal integrated into the package itself and uses a built-in temperature sensor to periodically measure the temperature of the crystal and, by switching different internal capacitors in and out of the crystal circuit, can precisely adjust its frequency so it remains constant. It’s specified to keep time within 2ppm from 0°C to +40°C, and 3.5ppm from -40°C to +85°C, which means the clock would only drift 63 and 110 seconds per year, respectively. Very cool.
I recently purchased a BSide ACM03 Plus clamp meter so that I could do some high current measurements for my tab welder project. This meter can be bought on eBay for around $25, which makes it one of the cheapest Hall effect clamp meters on the market that is capable of measuring both AC and DC current.
Since this is such a cheap meter, I wasn’t expecting much. But it actually feels really sturdy in hand and the construction looks reasonably solid, which is certainly a good start. It came with a nice little black pouch inside a non-descriptive cardboard box. It even includes a decent product manual.
Manuel Azevedo did a review of Akafugu’s modular VFD clock:
I discovered this wonderful tiny VFD clock by chance, while browsing Tindie for novelties. As I’m a newcomer to this Nixie/VFD world, I was not aware that Brian Stuckey already did an article in 2014 on a previous incarnation of this clock (Akafugu Modular VFD Clock).
I contacted Per Johan Groland, owner of the Japanese maker Akafugu that makes these clocks, for all the shields I could get my hands on – The only shield I did not order was the 4 tube IN-4/17 shield, which Brian already tested and which I find does not do this clock justice.
See the full post and more details on his blog, TubeClockDB.
The Dallas Semiconductor DS1284 (and related DS1286 which integrated a battery and crystal in the same package) found lots of use in industrial control and test equipment.
30 years ago processor chips contained not much other than the processor. Utility functions such as real time clocks, non volatile ram and watchdogs were always external.
Dallas semiconductor was quite successful in creating some of these utility chips which put a number of functions into a single device. The company was eventually acquired by Maxim in 2001.
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.