Various sound card interfacings This page is an attempt to correlate the interfacing schemes for various Radio models, and Sound Card configurations.  Since 26th December 1998, when the sound card version of PSK31 was first introduced to the Ham community, and after much dialog, __ Designed by Ernie Mills, WM2U

Versatile Hybrid Synthesizer for UHF & Microwave Projects Controlled by the PC parallel port, this hybrid DDS/PLL synthesizer delivers full-octave coverage between 1000 and 2000 MHz with sub-1 Hz resolution and commercial-quality phase-noise performance.  

VGA Hardware Screen Blanker It is a simple device that connects between your keyboard and VGA card feature connector, and will blank (or blink) the screen after a certain amount of non-keyboard activity.  This device is totally software and O/S independent.  The ONLY screen blanker that can be guaranteed to work! __ Designed by David L. Jones

VGA to RGB + composite sync-converter This article consists of one circuits which I have designed for connecting VGA card to other display devices than just a VGA monitor.  This circuits makes it possible to connect your VGA card to fixed frequency monitors and video projectors.  For some applications and system combinations some additional software is needed to get the system working __ Designed by Tomi Engdahl

VGA to TV Converter This article consists of one circuits which I have designed for connecting VGA card to other display devices than just a VGA monitor.  This circuits makes it possible to connect your VGA card to fixed frequency monitors and video projectors.  For some applications and system combinations some additional software is needed to get the system working __ Designed by Tomi Engdahl

VGA to TV Scart This VGA to TV converter is designed to connect VGA card to a television which has suitable 21-pin AV connector for RGB input (called EURO/SCART/Peritel connector).  if you Tv does not have this kind of connector, then you can't use this circuit __ Contact: IQ Technologies

VHDL procedure dynamically opens a file 12/17/98 EDN-Design Ideas (File contains many circuits.  Scroll to find this one.)  A simple VHDL-87 procedure opens a file whose name a command file or user conveys in runtime.  You can apply this technique to the reading or writing of data, control, and status files.  This procedure is useful for replacing the input stimuli file of a testbench without recompiling the code (with a different stimuli file name) or rename the stimuli file name.  In addition, the procedure can write the simulation results to a file whose name consists of the input file name and any preferred extension.   Design by Jacques Behar, Rockwell Semiconductor Systems, San Diego, CA

Video Clock Superimposer using PIC16c711 As a followup to my VCR Pong project, here is a gadget that is actually useful in the Real World! It superimposes the time of day, in "HH MM SS" format, in the bottom right-hand corner of an existing video signal.  My friend Scott uses it with his home security system

Video Connectors This connector is found on most Intel-PC's.  It's quite easy to feed VGA-monitors with Macintosh-signals (or the other way around: attach a Mac-monitor to an Intel-PC).  Most modern VGA-monitors are quite tolerant regarding vertical- and horizontal-sync frequencies.  

Video/Audio Switch (8 x 8) This is an 8-input x-output audio/video switch module to be controlled from a computer, for example fromparallel port.  Each audio/video output can be switched to any of8 inputs, separately.1-module drives1-audio/video output and has a34-pin connector to plug intosystem interface.  You can use video OPA-s on 4051 output instead.  Note that you can get full integrated video multiplexers from Maxim __ Designed by Peter Jakab

Visual & Audible Monitor for Electronic Interfaces Introduction Most of the modern PCs and embedded systems have digital interfaces as RS232, printer ports, LIN, etc.  for exchanging of commands and data with intelligent peripherals.Figure 1 is showing typical case...__ Electronics Projects for You

Visual Basic & AVR RS232 interface Control AVR micro-controllers via Visual Basic  software.  You can use some development board like  MCU 100, STK200, STK500 or build your own  board,  following the schematic.   __ Designed by Olesaether, Terie Frostad, Ingar Fredriksen, Morten W. Lund, Haakon Skar, Paal Kastnes

Visual Basic Models MDAC offset 03/13/98 EDN Ideas(File has several circuits, scroll to this one)  It's hard to imagine that, for such an old-hat item as a standard R-2R multiplying DAC(MDAC], there still exists some "dark area" in modeling and calculating its dc offset, VOFF, and related output resistance, RO.  You can obtain some information from References 1and 2 and other references regarding the code dependency of RO and VO, but the simplified formulas Page includes several designs.  Scroll to find this one Design by Olga Belousava, Los Alamos, NM, and Alex Belousov, New York, NY

Visual Basic-models MDAC offset 02/18/99 EDN-Design Ideas NOTE :  File has several circuits, scroll to find this one You often need to control the duty cycle of a square wave.  The circuit in Figure 1 works from a single 5V supply at a frequency of 100 kHz.  With minor component changes, you can configure it for a range of frequencies.  The circuit consists of a ramp NOTE :  sawtooth.  oscillator and a comparator.  The circuit compares the ramp to an externally applied voltage, VCNTRL.  When VCNTRL is greater than the ramp voltage, the PWM output is 5V.  The sawtooth oscillator consists of a current source NOTE :  R1, R2, R3, and Q1.  , a timing capacitor NOTE :  C1.  , and the oscillator-control circuitry NOTE :  R4, R5, R6, and IC1A The oscillator-control circuitry sets the upper and lower voltages of the timing capacitor at 3 and 1V.   Design by Olga Belousava, Los Alamos, NM, and Alex Belousov, New York, NY

Voltage-to-pulse-width converter spares microprocessor's resources 12/01/06 EDN-Design Ideas Simple circuit uses only three components and two I/O-port pins Design by James Christensen, Kris Design Co, El Cajon, CA

Web Server In a Box, Part 1 We're very excited about this project.  It will let you house your own website with possibly hundreds or even thousands of pages, all in a little box connected to the internet via your modem/router.  You don't need a computer to operate and house a websitethis little box does it for you and it can be accessed from anywhere around the world, at any time, even from a mobile phone which has a web browser.  In fact, it is a complete web server in a boxso we've called it WIB (Web server In a Box).__ SiliconChip

Web Server In a Box, Part 2 Last month, we introduced our new Web Server In A Box (WIB) and gave the full construction details.  This month, we show you how to connect it to your modem/router and guide you step-by-step through the set-up details.  We also show you how to activate a dynamic DNS service, so that you can access the WIB via the Internet.__ SiliconChip

Web Server In a Box, Part 3 In Pt.2 last month, we showed you how to connect the WIB to a network and gave the step-by-step setting-up details.  Most constructors will settle for the website provided but for those with special needs, this third article is for advanced users who want to customise the WIB to their requirements.__ SiliconChip

Where is the wiper? 08/08/02 EDN-Design Ideas You enjoy significant advantages when using DPPs(digitally programmable potentiometers] with increment/decrement serial interfaces.  Programming the serial interface is simple and fast, and you can adjust the potentiometer in real-time applications.  The interface, however, provIdeas no information about wiper position, and this information is important in some applications Design by Chuck Wojslaw and Dave Gillooly, Catalyst Semiconductor, Sunnyvale, CA

Why do we need Mixer? Article:  The mixing of a number of audio signals is such a common thing to do that one would expect the Net to be riddled with articles on how and why signals are mixed.  There are plenty of circuits that show how it can be done, but very little that explains the benefits or drawbacks of any particular scheme.   __ Designed by Rod Elliott  ESP

WIB: Web Server In a Box, Part 1 We're very excited about this project.  It will let you house your own website with possibly hundreds or even thousands of pages, all in a little box connected to the internet via your modem/router.  You don't need a computer to operate and house a websitethis little box does it for you and it can be accessed from anywhere around the world, at any time, even from a mobile phone which has a web browser.  In fact, it is a complete web server in a boxso we've called it WIB (Web server In a Box).__ SiliconChip

WIB: Web Server In a Box, Part 2 Last month, we introduced our new Web Server In A Box (WIB) and gave the full construction details.  This month, we show you how to connect it to your modem/router and guide you step-by-step through the set-up details.  We also show you how to activate a dynamic DNS service, so that you can access the WIB via the Internet.__ SiliconChip

WIB: Web Server In a Box, Part 3 In Pt.2 last month, we showed you how to connect the WIB to a network and gave the step-by-step setting-up details.  Most constructors will settle for the website provided but for those with special needs, this third article is for advanced users who want to customise the WIB to their requirements.__ SiliconChip

Wire Between Multiio Card & Joystick Connector Some PC multi-IO cards have a 16 pin header in the circuit board which is wired to the joystick connector (fitter to other slot place) using flatcable.  The wiring is straight one-to-one connection but, due to the different numbering scheme of the gameport connector vs the 16-way header, the pin numbers don't necessarily match (pin 16 in header is ocource lef not connected because joystick connector has only 15 pins) __ Designed by Tomi Engdahl

Wire Parameter Calculator This Javascript web calculator will calculate the resistance and ampacity for copper wire based on the gauge.  Both metric (mm) and American Wire Gauge (AWG) are supported.  Note: Ampacity is based on a curve fit to MIL-STD-975.  To see the wire table that this calculator is based on as well as important information about wire insulation temperature ratings __ Designed by Brad Suppanz

Wireless Keylogger-Do It Yourself! Part 1 Introduction Familiar with the concept of hardware keylogging? A hardware keylogger is a perfect solution for monitoring user activity, at very low risk of disclosure.  A hardware keylogger is a purely electronic device, so no access to the

Wireless Keylogger-Do It Yourself! Part 2 Power-up Once you have a transmitter-receiver pair of devices assembled, it's time for the first test.  We recommend to use a single computer for testing both devices.  First, power down the computer and connect the transmitter unit between the PS/2

Wireless Temperature & Humidity Sensor with USB this project is based on obdev's Remote Sensor example and their firmware-only USB implementation; the main change is the replacement of the analog sensors with a Sensirion SHT11 digital temperature and humidity sensor

Xtimer V1.0 with 4094 New design xTimer using CMOS shift register 4094 for driving 7-segment LED directly!.   __ Designed by Wichit Sirichote

XY Keypad uses µC's Serial Port 10/10/96 EDN-Design Ideas Interfacing an X-Y keypad to a microcontroller usually uses a parallel port of 8 bits or more.  But with the circuit shown in Figure 1, a more efficient interface using a microcontroller's serial port reduces the number of connections required from eight to three.  This interface uses the MM74C922N, a National Semiconductor keypad encoder, Design by James Mears, National Semiconductor, Tacoma, WA

Yaesu FT-897, FT-857 & FT-817 transceiver-PC interface (YFPI) This interface is used to fully control a transceiver, from a personal computer, when operating digital amateur radio modes (made in January 2006) __ Designed by Bjarke Korsgaard

Z80 Computer The successor to the Great Z80 Computer project.  The new Z80 computer is much simplified in comparison to the original, but in many cases borrows ideas and circuits from it.  When it is working I will be able to extend it as time permits __ Designed by Hans Summers

Z80 CPU NiCd/NiMH charger computer No Schematic __ Designed by Thomas Scherrer OZ2CPU

Zeiss OPMI-1 LED Conversion I was lucky enough to get an old Zeiss OPMI-1 surginal microscope, with very high quality optics.  Surgical microscopes differ from conventional ones in that they leave plenty of room between the subject and the microscope to work with hands and tools, which makes them ideal to work in electronics.   __ Designed by Roberto Barrios EB4EQA

Zero-Power A/D Converter Uses Printer Port 07/06/95 EDN-Design Ideas You can use a desktop or laptop PC to monitor physical variables such as temperature or pressure.  A convenient way to do this is to connect an A/D converter through the ubiquitous Centronics printer port[ Design by Dhananjay Gadre, IUCAA Instrumentation Lab, Pune, India

Zobel Network Tames Reactive Loads 12/21/95 EDN-Design Ideas Stability problems can arise in applications in which an amplifier must drive a reactive load.  Most amplifiers can easily drive purely resistive loads with no stability problems.  However, some reactive loads can cause an otherwise stable amplifier to ring severely or oscillate.  A good example is an audio-power amplifier.  The device’s load is a loudspeaker, which Design by David Albean, Thomson Consumer Electronics  Indianapolis, IN