I recently discovered an interesting application note from National Semiconductor in October of 1999. The article details nine sine wave generation techniques. Some techniques can be accomplished several ways so there are more than nine circuits available. The note also tabulates each technique with its frequency range, typical distortion, and amplitude stability. Both fixed frequency and adjustable frequency oscillators are covered. The simple crystal oscillator also has one of lowest distortion rates.
Everyone has seen the infomercials for cold heat™ soldering irons. They seem to answer all the easy questions. How much does it cost? Can anybody use it? Can it replace my old worn out iron? However they leave out the most complicated question. How does cold heat™ work?
This circuit remains broken until you put something conductive, like solder, in contact with both halves of the tip. The solder completes the circuit… Resistance in both the solder and the tip produce heat, and the solder melts.
Personally, I have never used a cold heat iron. Everyone who has either love them or hates them. How Stuff Works was more comprehensive than your friendly infomercial and mentioned a few downfalls they came across.
We suspect that they have the knack for using just the right amount of pressure at just the right angle, completing a circuit without shorting out any electrical components being soldered or breaking the tip.
I dugg up an interesting article describing the ‘free electron’ and his role in a company. “The Free Electron is the single most productive engineer that you’re ever going to meet.” Although I have not spent significant time in the ‘real world’, I definitely know a few characters that meet his criteria. I have to say that working with them was more of a nuisance until they pulled something spectacular off.
A recent post regarding high altitude balloons in the DIY Live Electronics Forums reminded me of an older altimeter project I wanted to copy for my model rockets. His original design uses a Basic Stamp to record pressure data from a sensor. Due to price constraints and chip loss, he changed to the cheaper PIC microcontroller. Later designs implemented a accelerometer and temperature recording as well.
The site contains schematics and source code, making it an excellent starting point. There is also an Excel spreadsheet to linearize the pressure output and converting it to altitude.
Too bad I lost my interest in model rocketry when I moved into ‘the city.’ Small rockets in the park are not as fun as all the space we had on Daddy’s farm.
Research at Cornell has made the first steps in evolutionary robotics. Their robot successfully make copies itself without any human interaction.
The next step is to train the robots to optimize themselves while reconstructing. Their research concentrates on how life adapts, evolution, and replicating these concepts in robots.
The Motley Fool has an interesting interview with long-term forecaster Paul Saffo of the Institute of the Future entitled, New Year’s 2016: I, Robot Investor. About half way through, the following text finally becomes of interest:
To me, it is pretty clear what the next big, out-of-the-blue industry will be. And it will continue the pattern of a new industry emerging every decade or so. In the ’80s, it was the personal computer… Now we are teetering right on the edge of a revolution in the robotics industry – consumer robotics in particular.
His job is to watch for the type of disruption recently caused by iRobot and Intuitive Surgical. “60% of Roomba owners had given their Roombas names.” He also mentions iRobot is delivering an ‘advanced’ product at a reasonable price, a sign robots are becoming practical.
In my opinion, this is not extremely out of the ordinary. What percentage of Roomba owning geeks has a name for their car or computer? I am sure it is very far above the national average. From an engineering standpoint, the price of the Roomba is a function of its simplicity, not price drops at a warehouse or research and development.
Although I am skeptical, I do believe that robotics is where the mp3 player was 6 years ago. The field is just waiting for something the general public will go googly eyed over.
The MCP100-XXX family of integrated circuits is designed to monitor a voltage source for drops below a hard-coded voltage. The chips are intended to reset a microcontroller whenever the voltage drops. However, the output can be directly routed to an LED (low-battery indicator) or sent to an input pin of a microcontroller for monitoring as described in Electronic Design.
The program simply monitors RB0. If there’s a logic 0 on that input, the program flashes pin 17 (LED), indicating to the user that the battery voltage is below 3.15 V dc.
Block Diagram of MCP100 chip
Check out the MCP100/101 datasheet for details. In small quanties, these chips can be had for 33 cents.
