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Ethernet 10BaseT simulator jig yields zero emissions - 10/22/98 EDN Design Ideas: (FILE
has several circuits, scroll to find this one) A test jig (Figure 1) is a valuable tool because it evaluates RF emissions from Ethernet unshielded-twisted-pair (UTP) 10BaseT LAN-interface devices without contaminating the measured results with its own RF emissions. When an RF-emissions-measurement lab tests a multiport, UTP 10BaseT Ethernet device for compliance with FCC-radiated emission limits, the test is meaningful only if the device transmits data packets from all 10BaseT ports. Design by Glen Chenier, Fujitsu Network Communications, Richardson, TX
Ethernet Weather Station - Using an add-on card to the already existing avr ethernet board we build a weather station. That is: A weather station with a build-in webserver. My original plan was to have sensors for temperature, air pressure and wind. I started a prototype and it worked very well except for the wind measurement part. I plan to improve the wind measurement hardware and add it at a later point in time. __
Everything You Always Wanted to Know About the ICL8038 - The 8038 is a function generator capable of producing sine, square, triangular, sawtooth and pulse waveforms (some at the same time). Since its introduction, marketing and application engineers have been manning the phones explaining the care and feeding of the 8038 to customers worldwide __ Designed by Bill O'Neil
Everything-that-moves alarm - A crucial failing of proximity detectors is their unreliable and tricky nature. This is where they are used to detect humans, not to speak of smaller living beings. One common approach is to detect __ Designed by © Rev. Thomas Scarborough
Evolved-Analysis Technique Provides Greater Insight - 12/05/96 EDN Design Ideas: Circuit-analysis techniques often fail to provide true insight into network design. A previous EDN article (Reference 1) introduced the Extra Element Theorem (EET) and gave designers a powerful circuit-analysis technique that provide as useful symbolic results. The article highlighted EET specialized to an impedance function and applied it to a bridge circuit with a voltage-dependent current source, but the article stopped short of explaining why the method works. Design by Celestino A Corral, Scientific-Atlanta Inc
Exacting noise test ensures low-noise performance of low-dropout regulators - 05/11/00 EDN Technical Article: Although verifying that a low-dropout regulator meets its dropout specification is straightforward, verifying its noise performance proves more difficult. You have to pay careful attention to the test setup, including the voltmeter you use. Design by Jim Williams and Todd Owen, im Williams, EDN's most revered contributor-At 63 years of age, Williams passed away in June 2011 after a stroke.
Excel offers painless LCD initialization - 09/20/01 EDN Design Ideas: To display a font or a symbol on an LCD, you need to convert the desired character into numerical data. Creating the data for an entire font set requires specialized tools; even with these tools, the task can be daunting. Alternati Design by Alberto Bitti, Eptar, Lugo, Italy
Excel Spreadsheet Measures Analog Voltages - 01/21/10 EDN Design Ideas: Turn an unused parallel port into a data port Design by Yury Magda, Cherkassy, Ukraine
Excel Spreadsheet Yields RLC Best-Fit Calculator - 28-May-09 EDN Design Ideas: Excel lets you automate engineering functions to find best-fit values of resistors, inductors, and capacitors Design by Alexander Bell, PhD, Infosoft International Inc, New York, NY
Exclusive 2.5 GHz Frequency Counter - A frequency counter is one of the most important measuring tool we need as Homebrew's of RF electronic. This frequency counter has very high performance and still is very easy to build and to use. Anyone can build it and have a professional frequency measuring tool. The counter is based around a LCD display with 2 lines and 16 chars. __
Exclusive 2.5 GHz Frequency Counter with Blue 2x16 LCD display - This project explain a very powerful frequency counter which has many useful software functions. The software can add or subtract 3 different iF frequencies (±455 kHz , ±10.7 MHz and ±21.4 MHz). You have also two level of resolutions, 1kHz and 100Hz __ Contact maxit91 @ hotmail.com
Expanded Scale 12v Battery Voltage Monitor - The circuit below expands the battery voltage monitoring scale for a 12v battery so a more accurate voltage reading can be made. The numbers printed onto the face of a standard 0v to 5v meter are changed so the scale ranges from 10v to 15v. http://archil. . . Circuit by David Johnson P.E.-October, 2005
Expanded Scale Battery Volt Meter - This circuit is used to measure the voltage on a 12V (nominal) lead acid rechargeable battery system. it was specifically designed for use in solar powered systems, but is general enough that it can be used for automotive or other 12V systems. Lead acid batteries normally spend their working lifetime in the voltage range of 11-15 Volts. This meter circuit __ Designed by G. Forrest Cook
Expanded Scale Voltmeter - I have a 12v batter charger I put together many years ago from bits and pieces found in the junk box. its been a good little light duty charger, but was lacking any form of battery monitoring, so I decided to give it an upgrade with a expanded scale volt meter and amp meter__ Home Power Magazine
Expanded-scale indicator revisited - 08/08/02 EDN Design Ideas: The visualization aid that a previous Design ideas describes allows only the expansion of the upper end of the scale (Reference 1]. But what can you do if, according to your project requirements, you need to expand the middle region of the scale? Figure 1a illustrates the challenge. A voltmeter comprises a 100-µA dc meter and a series resistor Design by Abel Raynus, Armatron International Inc, Melrose, MA
Expanded-Scale Voltmeter Uses Just Two Parts - 01/20/94 EDN Design Ideas: The expanded voltmeter doesn't require trimpots to obtain usable accuracy or require the tedious selection of Zener diodes. This circuit consists of only two parts and a5V meter. The circuit is completely linear and requires no calibration except the rare mechanical zeroing of the meter. By using Design by DD Cantrell, North Valley Research, Los Molinos, CA
Experimenter's Chamber - This experimenter's chamber is made from a 4" (10 cm) diameter, 5.5" (14 cm) tall tin with a tight-fitting lid. A 5-way binding post is mounted in the center of the can and a 4" (10 cm) wire is suspended from the post inside the can. The wire length is short enough to insure that it doesn't touch the lid. Another all-metal binding post and pin are installed in the bottom of the can, and a sheet of gray insulating plastic is glued into place to keep hastily constructed experiments from contacting the can. The electrometer circuitry will be extremely sensitive to stray electric fields, so a shield is mandatory. Another can previously containing mints is pressed into service __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Extend Battery Life - 07/29/10 EDN Design Ideas: Using a relay, the circuit completely disconnects the batter during to eliminate power consumption - two previous Design ideas - describe simple ways to automatically disconnect a battery from its load after a preset on period, which extends battery life (r Design by José M Espí, Rafael García-Gil, and Jaime Castelló, University of Valencia, Valencia, Spain
Facilitate oscilloscope Debug of small microcontroller systems - 07/07/14 EDN Design Ideas: A probe-to-the-metal approach is often the best way to debug a small µC system, and here’s some code to help out. if you develop an application on a small microcontroller, your diagnostic tools for debugging of the program code might be very limited. This Design idea introduces a simple debugging routine for plotting the binary value of one byte on a scope display. it uses one output pin of the microcontroller. Design by Josef Valasek
Fast Amplifiers Simplify AC Measurement - 05/09/96 EDN Design Ideas: The availability of new high-speed amplifiers makes it possible to measure fast-moving ac signals using a simple and inexpensive circuit. The peak-reading voltage-measurement circuit in Design by Chester Simpson, National Semiconductor, Santa Clara, CA
Fast Integer Multipliers Fit In FPGA - 05/12/94 EDN Design Ideas: You can fit a fast and compact digital multiplier into a field-programmable gate array (FPGA]. The technique involves using small look-up tables to find partial products and then adding the partial products. The key factor for making the design compact, fast, and easy to implement is to make the look-up tables for the partial products as small as possible. This multiplier can quickly multiply a number by a constant; changing the constant momentarily takes the multiplier off-line Design by Kenneth David Chapman, Xilinx Ltd, byfleet, Surrey, UK
Fast-settling picoammeter handles wide voltage range - 09/14/06 EDN Design Ideas: Versatile circuit converts picoamperes to millivolts Design by Rob Whitehouse, Analog Devices, Wilmington, MA
Fatigue Testing - This fatigue testing circuit is very simple and easy to build and will determine how tired a person is. it has been discovered that the highest light frequency that a human can detect is negatively influenced by his fatigue. This circuit is based on 555 timer that is connected here as an astable multivibrator. its output is __ Designed by Popescu Marian
Femto Capacitance Meter - This meter measures into the low femtofarad area. Measuring in the femto area allows the smallest capacitors to be measured with precision. Such capacitors are commonly used to compensate for input and stray capacitance in amplifiers. __
Ferrocart Vibrator App Note - Some notes on the design of vibrator power supplies as used in car radios, inverters, etcincludes Ferrocart type numbersThese were made by Astor and mainly used in their car radios __ Contact blehack @ yahoo dot com
FET based metal Detector using MPF102 / J310 BF998 FETs - Making a metal detector was always my dream. I was curious listening to those beeps at airport for which dad explained that they were metal detectors. Which did not mean anything to me. Last summer I had opportunity to find secrets behind this little stuff from my dad which turnout to be simple project one can make at home. __ Designed by Nina Gajjar
Field Strength Indicator-Analog only - The circuit is powerd by a single 1.5 volt AA cell. The current drain is so small, about 60 microamps, I didn't bother with an on-off switch -I just slip a battery in for the day, and hope I remember to remove it when i'm done. The supply voltage can be increased up to the breakdown voltage of the transistors to increase the sensitivity, but beware - the sensitivty to thermal drift will increase as well. __ Designed by Dick Cappels
Field Strength Meter - The circuit draws less than 10 uA with no signal so no switch is required. The variable capacitor is adjusted to tune the meter to the desired frequency by adjusting for the highest meter reading when held near the transmitter's antenna. if the meter reaches full scale during tuning or use, move the meter further from the antenna. (As you peak up a transmitter, you may need to move the meter several times to keep it on scale.) The MPSA18 may be replaced by other high gain NPN transistors, if desired. This meter has an "expanded scale" in that it goes from a zero reading to full scale over a fairly small signal level change making fine tuning easy. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Field Strength Meter - This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM or FM modulation or just a plain carrier wave. __ Designed by Andy Collison
Field Strength Meter for 2.4 Ghz Wireless LAN - The original diode in the Microwave detector has been hard to find. I have found a supplier for the diodes. Purchased here: http://www. xs4all. nl/~barendh/Cateng/Cateng_diode. htm Site Main Page : __ Designed by John Samnin
Field strength meter for the 137 kHz band - The original diode in the Microwave detector has been hard to find. I have found a supplier for the diodes. Purchased here: http://www. xs4all. nl/~barendh/Cateng/Cateng_diode. htm Site Main Page :__
Field Strength Meter MkI - This Field Strength Meter has been specially designed for our FM bugs. it is capable of detecting very low power transmitters and will assist enormously in peaking many of our FM transmitters that have a coil in the output stage that can be adjusted for optimum output ( __ Contact Collin Mitchell
Field Strength Meter MkII - A Field Strength Meter is essential when designing and building transmitters. it provides signal strength values and allows us to compare and estimate the efficiency of a transmitter and its expected range. __ Contact Collin Mitchell
Field-strength meter - I saw this circuit in an old issue of "73 Radio Electronics". I built it, but it didn't work well, so I changed a few components to get better sensitivity__ 73 Radio Electronics
Field-strength meter - This is a very straightforward circuit. The first stage acts as a crystal receiver. Use a germanium detector diode (like 1N34, but AA119 is much more common in Europe) , a silicon one won't do. The frequency is determined by L and C. For the FM band VHF, wind a coil 5mm in diameter, 6-8 turns of coated wire 1mm thick. You can always vary the frequency by spacing the turns a bit looser or tighter. C is much less critical. Something around 100p is preferable, though. __ Contact IQ Technologies
Filter Choke Analyzer - I have recently had several exchanges of emails with someone outside of north America who completed this project. He reports that the meter is now functioning but not without a few problems, most of which were caused by me. Based on this experience I have made a number of changes to the text and the schematic diagram. The beginning of the construction section will list the changes. __ Designed by Max Robinson
Fire Alarm - With the onset of summer, chances of fire accidents increase. Such fire accidents can be prevented if timely alarms are available. The circuit presented here warns the user against such fire...__ Electronics Projects for You
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