Designing Ideas
Design Ideas editor Paul Rako introduces EDN's latest engineer-submitted circuit designs, providing links to related articles from our archives, design resources elsewhere on the Web, and just-plain-fun stuff.
Bob Pease on bounding and clamping techniques
Tim Hoeppner, a product development engineer at Norscan Instruments Ltd. asked if he could purchase and old 1983 EDN article that Bob Pease references in his excellent book on troubleshooting. Since I have paper copies of EDN back to 1974, his request landed in my inbox. I guess nominally we are supposed to charge 25 bucks for old articles, but I could tell Tim was a diligent engineer with an inqu ...... Read More
Comments (23)Happenings at Orcad, Altium, and Sunstone, plus free DesignSpark
I really like Altium, I recommended that the whole company should use it when I worked at National Semiconductor (now a Texas Instruments division). What has happened since then is that Altium makes and sells their own FPGA demo boards. This has had a great benefit, since it puts real live board designers right next to the programmers making the CAD tool. So Altium has really adopted a lot of thos ...... Read More
Comments (9)A Jim Williams barometer schematic from 1992
Fran Hoffart was wise enough to take this picture of a Jim Williams schematic back in 1992. It is a design for a barometer. I was at the Computer History Museum today to record a video interview of my memories of Jim. That got me a little bummed out. I wrote up an editorial for the next EDN issue. The Museum is doing a display about Engineers at Work” and Jim’s bench is going to be a ...... Read More
Comments (20)Something cute from Jim Williams
My team-building buddy Tim “TimerBlox” Regan over at Linear Tech sent me a note about a cute thing Jim Williams did in an app note that must have slipped by the serious and somber editing team over there. Tim writes: Paul, here’s something you might get a kick out of. I did, but it’s my kind of humor. This is a Williams circuit from at least 25 years ago using the LT101 ...... Read More
Comments (14)Equations prove validity of capacitance and inductance measurement circuit.
Thoughtful reader Raymond Laagel of Mulhouse, France sent a note with a proof of a Design Idea we published back in 2010. The DI was called Circuit measures capacitance or inductance, and it was by the prolific contributor Jim McLucas. Jim had another capacitance measurement idea back in 2009. Monsieur Laagel’s proof was chock full of equations, and would take a day or two to prepare for pu ...... Read More
Comments (0)A super-heterodyne AM radio operates off 9V using Russian rod tubes
Joe Sousa, the analog aficionado that runs the Philbrick Archive sent me a neat design for a super-heterodyne radio receiver using tubes. When I hear “tubes” I think “high voltage”. That’s the cool thing about Joe’s design, it works off of a 9V battery. I thought he might be using a Nuvistor tube like the one my buddy Eric Schlaepfer showed me last week. I ...... Read More
Comments (6)Electronic Circuits Manual has 988 pages of design ideas
Several alert readers mentioned in comments to the previous blog that there is a great huge book of design ideas called the Electronic Circuits Manual. Sure enough, my team-building buddy, Linear Technology applications manager Tim Regan, had a copy. I borrowed it last week and promptly ordered a used copy of Amazon. There are many available for 20 cents, plus 3.99 shipping but I splurged on the 3 ...... Read More
Comments (9)Paul Rako now edits Design Ideas
I am delighted to tell you all that I will now be editing Design Ideas. I will still be writing articles for EDN, but Bill Schweber is our official analog editor for both EETimes and EDN, especially for product stuff. Martin Rowe will be full time at Test and Measurement World. It was really unfair to Martin to have him doing Design Ideas, since that means he has two bosses, Rick Nelson at T&M ...... Read More
Comments (18)Design Ideas detail novel power supplies
You can employ a pin-limited microcontroller to develop a suitable dc/dc-boost-voltage converter with the aid of a few discrete components. Tiny microcontroller hosts dual dc/dc-boost converters details a simple circuit where a microcontroller powered by an AAA cell generates a high enough voltage to backlight an LCD. Small capacitor supports telecom power supply during brownouts shows how to keep ...... Read More
Comments (0)Design Ideas interface to microcontrollers
The Design Idea in Circuit and software provide accurate recalibration for baseline PIC microcontroller’s internal oscillator uses three I/O lines to recover the internal calibration value by recalibrating against a reference clock, the 4-MHz crystal. The method in Microcontroller moving-dot display interface uses three I/O lines needs three output lines—data, clock, and latch— ...... Read More
Comments (0)Design Ideas control synthesizers
Peltier devices, also known as solid-state refrigerators, or TECs (thermoelectric coolers), actively cool temperature-sensitive electronic components, such as optical detectors and solid-state lasers. However, one TEC data sheet proviso that designers sometimes miss is that you always measure these parameters with the TEC mounted on an effectively zero-thermal-impedance—that is, perfect ...... Read More
Comments (0)Design Ideas interface to precision circuits
Chop the noise gain to measure an op amp’s real-time offset voltage introduces a new type of chopping. "Chopping the noise gain" is a simple way to measure the offset voltage in real time, so that you can subtract it and enhance DC precision. The circuit in Simple analog circuit provides voltage clipping and dc shifting for flash ADC converts a symmetrical inputvoltage range of 20.2 to 10.2 ...... Read More
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