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Digital and Analog Pulse Measurement Pete‘s innovative data acquisition system measures cosmic rays， natural background radiation， and emissions from radioactive objects captured from a scintillation probe and a Geiger tube. The compact system controls data acquisition processors， gathers the collected data， and formats the data for display. As a teenage electronics geek in the 1970s， I entered the regional science fair several times. My first project converted a TV set into a crude oscill...

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Theory, Construction, And Requirements The principles behind electric motors have been around for almost two centuries， but the technology has come a long way during the past few years. Jeff examines electric motor theory， construction， and requirements. Although Michael Faraday first showed the relationship between current flow and magnetic fields in 1821，it wasn‘t until 11 years later that these principles were used to demonstrate the first electric motor. Actually， it was the invention ...

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Processor Action Requires Power Supply Removal Fed up with corrosion？ Eliminate the contacts. Jeff replaced his old doorbell switch with a capacitive touch pad using only the pair of wires available at the door. If you are not in the market for a new doorbell， this solution could work well in a different project. I was frustrated for the last time. If I hadn‘t been walking by the door， I never would have known that my neighbor was standing outside patiently waiting for me to show. When I ask...

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Build Better Energy-Saving Electronic Systems Welcome to the Darker Side. Simple calculations can generate impressive figures，especially when calculating energy waste. According to Wikipedia， our worldwide energy consumption is around 15 TW， which is 15，000，000，000，000 W. Considering that there are around 6.5 billion people on Earth， this is an astonishing number. Let‘s assume that everyone is using the same amount of power， including developing countries，this comes out to an average ...

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The roots of Altera‘s MAX II go back about 30 years to the programmable array logic （PAL）device. This month， Tom covers the history of programmable logic chips and introduces you to MAX II technology. Say hello to his little friend. In this the twentieth year of Circuit Cellar magazine， I find myself contemplating new developments in the context of history. Like they say， you can‘t know where you are if you don't know where you started. This month， let‘s look at a chip whose roots go ba...

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An MCU-Based Monitor For A Communal Well Jeff‘s Microchip Technology PIC12F510-based system monitors the water filtration system in an underground well. The design indicates when the communal filtration system's brine tank is out of salt. We are beginning to see some signs of public panic due to water issues. I have read about towns whose water sources （e.g.， wells） are being threatened by pollution， both natural and man-made. I have also read about cases where upstream users are diverting ...

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With Celestron‘s SkyScout， you can explore outer space without leaving your backyard. The handheld device gives you point-and-click convenience to identify thousands of stars， planets，constellations， and deep-space objects.You don't even need instructions. Just turn it on and follow the directions on the LCD. ARM processor power brings the heavens to you. Adding exterior lighting to streets，parking lots， buildings， and signage makes our nights safer， but it unknowingly adds to the growi...

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You can add USB to your next project with Microchip Technology‘s new array of parts.The 8-， 16-， and 32-bit microcontrollers will complement your designs with USB peripheral support， embedded hosting， and dual-role and OTG capabilities. Many of us are just coming to grips with the idea of supporting a USB interface as the communications medium of choice for our product designs. PC manufactures have eliminated the DE9 （standard for years on every PC） and replaced it with USB （and FireWire...

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Triac Control Meets an Inductive Load Looking for more precise power control， Ed used a triac and a few supporting components to control high-power equipment. In this article， he describes everything you need to know about the circuits. The results might surprise you. Back in the not-so-good old days，controlling high-power equipment required big relays and motor-starting contactors； an armature‘s snap preceded the hum of large machinery and the whine of motors. Semiconductor power control h...

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Advances in video game technologies and controllers are changing the ways we interact with gaming consoles. If you don‘t want to buy expensive power pads and controllers， you can follow Jeff's lead and build your own controllers with much of the same circuitry. Dance dance revolution！ And what a revolution it was！ Konami‘s "Dance Dance Revolution"（DDR） was one of the first "video games" to involve its participants in a level of physical activity beyond typical exploration and defensive th...

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Print Sensing with Embedded Technology Identifying and matching fingerprints is a tedious process that involves huge databases.Today,a few companies are using embedded microcontrollers to create stand-alone print-sensing systems. Jeff examines the latest fingerprint security technology from Atmel. I thought the popular television show CSI： Crime Scene Investigation would have run its course by now. However， even with two spin-offs， it still isn‘t losing its appeal. Because I stare at a monit...

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In his last two columns, Ed discussed transformer action and the simulated triac control of an inductive load. This month, he describes a real-world application: circuitry connected directly to an AC power line. Having investigated transformer action in my February 2008 column（"Transformers，" Circuit Cellar 211）and simulated triac control of an inductive load in April 2008 column（"Triac Behavior，" Circuit Cellar 213），now it‘s time to put everything together and match theory with reality....

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Ed takes a look at IR proximity sensing after seeing a colleague's homebrew chord keyboard.Even if you don't need a hand-mounted keyboard, knowing how a contactless switch works should come in handy. Arecent Mid-Hudson Valley Linux Users Group meeting featured Greg Priest-Dorman demonstrating his wearable Linux computer system. He‘s been using the homebrew chording keyboard shown in Photo 1 for the last decade， with a succession of computers that each ran afoul of Moore's Law. The key click...

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After months of learning C, it's time to apply what you've learned in a real-world application.George explains how to tackle a real design problem from start to finish. You‘ve been learning C for a while now. Hopefully， you can read and write C code. This month， I would like to take a real design problem from the beginning to the end. Along the way we'll create a design， make design trade-offs， accept changes， and code the design. This should be interesting. DESIGN CHALLENGE A few months a...

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The StellarisGFX is a well-designed sound effects processor. The system‘s keyboard is used for navigating through the user menu.You can set the volume level and select effects such as overdrive， tube overdrive， and distortion. The clean sound of an electric guitar is not often used in rock and blues music. This is also the case when you examine a classic rock or blues record. Almost every beginner learning to play the electric guitar comes up against the same problem： the song he‘s trying t...

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