Powering an Ultrasonic Transducer

[Lindsay] has a wonderful writeup about a new toy in the shop, an ultrasonic transducer. The 28kHz, 70W bolt-clamped Langevin transducer by itself is not much use, you need a power supply, a horn to focus the energy, and a way to tune it. [Lindsay] starts off by showing how to find out the resonant frequency of the transducer, designing and building a high voltage high frequency AC power supply, and how to design a horn.

Not missing the meaning of DIY [Lindsay] casts and machines a horn for the transducer with a high level of precision as this will also tune the horn to the correct frequency. Once some brackets are machined the whole setup is put through some fun experiments in water and lemonaide, but the real purpose is to drill fine holes in glass for his home made Panaplex displays.

Join us after the break for a short video.

[Read more...]

Transmitting power and data through thick metal enclosures

So let’s say you have a submarine, or a nuclear containment chamber which has walls made of thick metal. Now let’s say you want to transmit power or data through this wall. Obviously you’re not going to want to drill a hole since this wall is either keeping seawater out, or potential contamination in, but wireless signals aren’t going to travel well through dense metal. [Tristan Lawry's] entry in the Lamelson-MIT Rensselaer Student Prize seeks to address this issue by using ultrasound waves to transmit data and power.

In the video after the break [Tristan] speaks briefly about his project, then demonstrates the transmission of power and digital audio simultaneously through a two-inch thick steel plate. This is accomplished with a set of piezo transducers attached to both the inside and outside of the plate. Communications originate by feeding electricity to one transducer, which sends ultrasonic vibrations through the material to be received by its counterpart on the other side. It’s easy for us to understand data transmission conducted in this manner, after all that’s how the knock block receives information. What we don’t understand is how it can “transfer large amounts of electrical power”. If you can explain it in layman’s terms please do so in the comments.

[Read more...]