by Joonas Pihlajamaa @ codeandlife.com:
Today’s post is something I’ve prepared for a long time. Hardware-wise it’s a simple thing – ATtiny45 emulating a PS/2 device, sending a keypress when three knocks are detected in the attached piezoelectric sensor (or piezo buzzer as they are also called). But if your computer can boot on PS/2 keyboard input and you have your computer stowed somewhere hard to reach (or just want to impress your friends), it’s a pretty neat little gadget! Here’s a video of it in action:
Turning PC On with a Knock using ATtiny45 - [Link]
by Stephen Evanczuk @ digikey.com:
Pulse-energy-harvesting applications convert bursts of energy to sufficient power for operating simple circuits such as wireless switches, wireless data loggers, remote controls, and the like. To build these designs, engineers can draw on a wide variety of available ultra-low-power ICs and energy transducers from manufacturers including EnOcean, Linear Technology, Linx Technologies, Maxim Integrated, Measurement Specialties, Microchip Technology, Mide Technology, ROHM Semiconductor, Schurter, Silicon Labs, and Texas Instruments, among others.
Powering Circuits through Pulse-Energy Harvesting - [Link]
Researchers at Columbia Engineering and the Georgia Institute of Technology have reportedly made the first experimental observation of piezoelectricity and the piezotronic effect in an atomically thin material, molybdenum disulfide (MoS2). The piezo effect is traditionally thought of as one property of hard crystalline quartz. Using this new material it would now be possible to manufacture electric generator and mechanosensation devices that are optically transparent, extremely light, flexible and elastic.
Atomically thin Piezo Material - [Link]
80 dB acoustic signal at only 3V power supply and a really miniature size place this new component into a top class.
Belgian company Sonitron and its top-level products ar probably familiar to you from our articles and from our offer in this segment. We continue in increasing of standard stock types and this time we have here an extraordinary interesting type – SMA-13LV, interesting mainly for low-voltage applications. Series of buzzers marked as “SMA” is known by its variousness, as we find here types with loudness of 75-98 dB, THT and SMT vesions, and versions with a stable, as well as intermittent signal. Various izes from 13 to 30 mm with a pitch of 7.5 to 20.32 mm enable to select the right type for a given application. In general, bigger types provide a more loud signal, but it depends on a concrete type. This series is suitable for general use – everywhere, where a reliable buzzer is necessary, including industrial conditions.
For a succesfull use, it´s only necessary to connect a suitable supply voltage – usually in extremely wide range (for example 1.5-15V). Usually, on the upper end of a supply voltage range we get the highest loudness and at lower voltages we receive a higher lifetime.
Very similar is also the SMAT series (transducers), which in contrast to the SMA series doesn´t contain a driver, that´s why it needs an extenal electronics.
For really tough conditions, the Sonitron SAP. series is suitable. These are buzzers for various usage in traffic, for example as a reverse movement indicator (danger of close approximation). They excell in extreme rigidity, what make them widely used even in avionics, miltary and trucks. SAP series has a specifi usage, that´s why we keep these types as items upúon request.
Another novelties in our standard stock offer can be found below this article. Detailed information can be found in datasheets at particular types and in the new Sonitron 2014 catalogue.
Piezo buzzer Sonitron SMA-13LV deploys maximum from a minimum - [Link]
Shabaz over at Element14 writes:
This post is about an interesting, low-cost sensor that doesn’t need much processing to use, and has some unique characteristics – a PVDF (polyvinylidene difluoride) Piezoelectric sensor. The sensors looks like a small strip of plastic, and can be used for detecting movement or vibrations even into ultrasound. Such devices can help sense in many practical, real-world scenarios. They are extremely sensitive, low cost and easy to use. Some simple practical experiments with these sensors are described, finally looking at detecting ultrasound.
Impact, vibration and ultrasound sensing with PVDF Piezo sensors - [Link]
Researchers Steve Dunn at Queen Mary University and James Durrant at Imperial College London have been experimenting with a new design of thin, flexible solar cell made from zinc oxide. Manufacturing costs of the new cells will be significantly lower than conventional silicon based technology. The only disadvantage is their poor efficiency; just 1.2 %, a fraction of that achievable with silicon.
The material also exhibits piezo-electric properties, nanoscale rods of the material generate electricity when they are subjected to mechanical stresses produced by sound wave pressure. Sound levels as low as 75dB, equivalent to that from an office printer, were shown to improve efficiency. Durrant said “The key for us was that certain frequencies increased the solar cell output, we tried our initial tests with various types of music including pop, rock and classical”. Rock and pop were found to be the most effective. Using a signal generator to produce sounds similar to ambient noise they saw a 50 % increase in efficiency, rising from 1.2 % without sound to 1.8 % with sound.
New Solar Cell Shows a Preference for AC/DC - [Link]
by Publitek European Editors
There are many different types of accelerometers for industrial applications, ranging from the latest micro-machined capacitive devices to traditional rugged piezo electric crystals. The boom in portable devices and the advantages of knowing the position and orientation of the equipment, as well as the increased use of accelerometers in vehicle air bags, has led to an explosion in the different types of devices in recent years. All of this is to the advantage of the engineer who can use the wide range of devices for different applications, from monitoring to position measurement.
Sensor Technologies for Accelerometers - [Link]
If you´re searching for a piezo transducers, buzzer, siren or a loudspeaker with a high efficiency and a high reliability, you´re on the right address. Narrow specialization, long-term know how, many patents and an own “in-house” production make the company Sonitron a European leader in a segment of piezo components.
An absolute majority of Sonitron components is resistant to harsh environment, dust and gases. In the offer we can find many types usable in critical applications (medical, military and other). Thanks to this fact, Sonitron also supplies such customers like for example NATO, Volvo and AirBus.
Directly from our stock, we´re able to provide you with many piezo components – piezo elements (transducers, without a driver) but also with drivers (sirens, buzzers) usually working in a very wide voltage range (for example 2-35V). A more detailed description of a piezo technology and description of products can be found in the Sonitron catalogue (25MB).
In case of interest even in non-stock types, please contact us at email@example.com.
Sonitron – piezo transducers, which you can rely on – [Link]
This instructable will guide you through creating your own Arduino based Kitchen Timer. This is a quite simple project, requiring little or no programming or electronics knowledge, just the willingness to learn and fiddle – an ability most useful for modern man.
This kitchen timer is simple enough, press and hold a button and it will count up it multiples of five minutes, until you release the button. Upon doing so the timer will flash, and begin counting down. This timer includes an alarm and a display, with a piercing piezo buzzer to get your attention.
The arduino, laptop, protoshield, and USB Cable excluded; I took every electrical component from an old or broken device. Try to recycle things, its easy to get hold of broken electronics for free so make the most of it! See any jumpers on this design? No, paper clips are much better – cheap as chips and more sturdy too!
Arduino Kitchen Timer - [Link]
Piezoelectric materials are about as close to magic as you can get. They turn physical pressure into electricity and can even turn electricity into physical pressure – an amazing sort of bidirectional converter for mechanical and electrical energies. Perhaps even more amazing is the fact that you can easily ‘grow’ your own piezoelectric crystals overnight using just a couple of common ingredients – awesome.
Collin’s Lab: Homebrew Piezo - [Link]