Novel transistor uses protons for charge transport

Scientists at the University of Washington (USA) have developed a new type of transistor that uses protons instead of electrons for charge transport. It is intended to simplify the interfacing of electronic circuitry to the brains of living organisms, since protons (positively charged hydrogen atoms) and ions are responsible for signal transport between nerve cells. Proton-based transistors are therefore better suited to controlling and monitoring processes in the brain.

The researches discovered that the natural biomaterial chitosan, obtained from squid pens and crab shells, is a good proton conductor. They then used it to fabricate a transistor that can generate proton pulses. The prototype device is a field-effect transistor with a source, gate and drain, but it operates with protons. [via]

Novel transistor uses protons for charge transport – [Link]

Self-learning driverless tractor

The department of Mechatronics, Biostatistics and Sensors (MeBioS) of Leuven University, Belgium, together with Flanders’ Mechatronics Technology Centre (FTMC) successfully converted an existing mini tractor into an autonomous self-learning field robot.

The tractor learns to identify soil characteristics, and on the basis of results controls its speed and steering angle allowing it to follow a certain route very accurately, all without a driver. Precision in the control of agricultural machinery is an important feature for organic farming.

Self-learning driverless tractor – [Link]


Low Dropout Regulators Deliver Quiet Power for Noise-Sensitive Circuits

System-level hardware designers pay careful attention to selecting the right analog signal path ICs for their specific applications. Each IC needs “clean

Flyback Transformer Drivers writes:

Flyback transformers are found in monitors, TVs or anything with a CRT, and are sometimes known as Line OutPut Transformers, or just LOPT. They are used for generating high voltage for the CRT, which is needed to create an electric field, which in turn accelerates electrons towards the screen, which finally excite phosphors and create the image you see. Flybacks are designed to work best anywhere between 15 to 150 kHz, so some experimentation is required to find the intended operating frequency. TV flybacks are generally designed for upper audio frequencies, which is the cause of the high pitched noise heard from a muted TV.

Flyback Transformer Drivers – [Link]

PS/2 Keyboard Interface writes:

The keyboard is the most common way for humans to input information into a computer. It has been around since before computers were main-stream and everyone was still using typewriters. Because of this prevalence in society, it’s important that we understand how to interface to the basic PS/2 keyboard.

This article will describe and show you an example of how to create a system capable of interacting with a keyboard in order to understand what keys have been pressed. The example system will be built on a breadboard using a PIC microcontroller to communicate with the keyboard and display output.

PS/2 Keyboard Interface – [Link]


The Story of the LM13600/LM13700 Transconductance Amplifiers

A neat write-up about this fun little chip, written by co-designer Don Sauer: [via]

The LM13600 was designed by Bill Gross and myself in less than 5 minutes. At the time the Consumer Linear IC design group was training a new mask designer. We needed something with a few transistors for her to learn how to arrange them in a optimum circuit arrangement while using minimum silicon area.

At the time, electronic Organs were being done using analog circuitry. I had just made a trip to one such company and of course they gave me a wish list of what kind of circuits they would like to see. The RCA 3080 has just come out and it almost gave the Analog Organ folks everything they wanted. They needed something for analog variable gain. The application was to shape the attack and decay of various waveforms.

But the 3080 was a true Operational Transconductance Amplifier in that it had a voltage input and a current source output. For most applications, an external buffer was needed.

At the time we were considering second sourcing the 3080 anyway. Also at this very same time, the 16pin plastic dip package had just been developed. So the development spec for the LM13600 was that it needed a schematic to train someone in IC layout. It needed to have 16 pins. And we were going to layout the 3080 anyway. The schematic part was easy. Just used the 3080 exactly. There were 16 pins, so we could just mirror the layout to do a stereo. That left 3 extra pins per channel. The simplest buffer was a darlington which needed two pins per channel. There were complaints about high levels in input signal generated too much distortion in the 3080. That could be addressed by connecting the left over pin to predistortion diodes.

The Story of the LM13600/LM13700 Transconductance Amplifiers – [Link]

Tiny Pong: More fun with ATtiny45 and VGA writes:

I’m still waiting for my cheap Bluetooth module from China which will serve as an input interface for my scoreboard project. In the meantime, I’ll show you how to convert your ATtiny microcontroller into a Pong game (with no input so far).

Tiny Pong: More fun with ATtiny45 and VGA – [Link]

How to find the location with GSM cells

The radio mobile network is made up of a number of adjacent radio cells, each of which is characterized by an identifier consisting of four data: a progressive number (Cell ID), a code related to the area in which that given cell is (LAC, or Local Area Code), the code of national network to which the cell belongs (MCC, an acronym for Mobile Country Code), and finally the company code (MNC, or Mobile Network Code), which obviously identifies the phone company itself. For this reason, once a cell name and coordinates are known, and considering the maximum distance allowed between this cell and a phone before the phone connects to a new cell, it is possible to find out, approximately, the most distant position of the phone itself. To explain how the systems works, we made this page. You have to insert the data of the GSM cells and then the PHP page gives you the position and the range.

How to find the location with GSM cells – [Link]


Adding auto turn-off to a cheap multimeter writes:

I bought this multimeter (Minipa ET-870C) a while ago for $17, great value. I got it because its nice to have around multiple meters for when you wanna measure both input and output voltage/current. I believe it was advertised to have an auto-off feature for 15 mins but it didn’t. This eventually lead to many drained batteries because I often forgot to turn it off after using it. So during a boring weekend when the weather outside was bad I decided to add this nice feature to the meter. I knew it had to be a small circuit to be able to fit inside the multimeter so I picked the tiny25 the smallest micro I had around.

Adding auto turn-off to a cheap multimeter – [Link]