Lightwave Clear-Air Scatter Test - After patiently waiting for the bright moon to clear the early evening skies, I was finally able to venture out for my first clear-air scatter test this past Sunday night. I had plotted the path on my Mayne island map and determined bearings as best I could, but the path was going to be very tight. __ Designed by VE7SL - Steve
Line receiver provides self test - EDN Design Ideas: 07/01/2016 Use a quad differential comparator to provide adequate self-test for systems using line receivers for differential input signals. Design by Jay L Richman, Bendix Flight Systems, Teterboro, NJ
Linear potentiometer implements logarithmic gain control - 10/23/1997 EDN Design Ideas: Trimmer potentiometers are ubiquitous components and are available in a variety of packages, resolutions, and temperature stabilities. However, none of these potentiometers implements anything but the usual linear function of resistance vs shaft position. This fact makes trouble for applications that need a wide dynamic-adjustment range. Design by W Stephen Woodward, University of North Carolina - Chapel Hill
Linear potentiometer provides nonlinear light intensity control - 04/28/05 EDN Design Ideas: Circuit matches light control to eye’s intensity-response curve Design by Stephan Goldstein, Analog Devices, Wilmington, MA
Linear Thermometer - T1 has a built in pair of thermistors with linearizing resistors custom scaled for a specific temperature range. , 0C to 100C in this example. The flying capacitor LTC1043 eliminates any dc loading on the precision network to maintain linearity over the entire temperature range. Amplifier gain is scaled to provide an output __ Linear Technology/Analog Devices App Note, Jun 21st 2011
Linear Wind-Power Meter Compensates for Temperature - 13-Nov-08 EDN Design Ideas: Using a free-spinning anemometer for wind speed and a diode-connected transistor for temperature sensing, this meter measures the wind power available for "green" power generation Design by W Stephen Woodward, Chapel Hill, NC
Linearize Optical Distance Sensors with a Voltage-To-Frequency Converter - 04/19/12 EDN Design Ideas: Create the mathematical inverse of an analog voltage by converting it to frequency and measuring the period. A popular series of inexpensive distance sensors integrates an infrared emitting diode, a linear charge-coupled-device array, and a signal-processing circuit in one unit. The output is a dc voltage, VS, that depends on the distance, D, in a nonlinear manner (Figure 1). Design by Jordan Dimitrov, Toronto, ON, Canada
Linearize thermistors with new formula - EDN Design Ideas: 03/03/2014 Optimize thermistor performance at any preferred temperature Design by Mark Biegert
Linearized NTC Thermistor - (spice design) __ Designed by Rick
Linearized Platinum Resistance Thermometer with ±0.025°C Accuracy Over 0 to 100°C - Platinum RTD's are typically driven with a constant current so that their resistance value directly translates to a temperature dependant voltage. Here the LT1001 and the LM129 create a constant current through the input 10K resistor which all flows through the sense resistor. A second amplifier inverts the signal to provide __ Linear Technology/Analog Devices App Note, Jun 21st 2011
Linearizes & Convert Thermistor Data - 12/07/95 EDN Design Ideas: Although the response of thermistors is inherently nonlinear, you can make the devices' resistance over a selected range of temperatures linear. You can convert the thermistor value to a voltage for display on either a DMM or a panel meter. The circuit in Figure 1 performs linearization and provide as gain and offset for a YSI 44031 thermistor, whose nominal resistance is 10 k[ohm] at 25ºC. Design by Matthew Beckner, Ball Corp Boulder, CO
Link Neatly Measures Temperature - 10/26/00 EDN Design Ideas: Figure 1 shows a convenient and neat way to measure temperature using the USB of a PC. An ADM1023 IC senses the temperature, and an Anchor Chips EZ-USB AN2131SCµC provide as control. The ADM1023 is a low-cost device with an accuracy of 1°C and a resolution of 0.125°C. The IC is a two-channel device that can measure its own local temperature and the temperature of a remote location Design by Mary Burke, Analog Devices, Limerick, Ireland
Liquid Barometer - Have you ever noticed how those technical-looking aneroid barometers in the stores all indicate a different pressure? And when you __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Liquid Level Alarm - Here is a simple circuit for liquid level alarm. it is built around two BC547 transistors (T1 and T2) and two timer 555 ICs (IC 1 and IC 2). Both IC 1 and IC 2...__ Electronics Projects for You
Liquid-Level Indicator - The LTC2990 is used to monitor system temperatures, voltages and currents. Through the i2C serial interface, the device can be configured to measure many combinations of internal temperature, remote temperature, remote voltage, remote current and internal VCC. The internal 10ppm/°C reference minimizes the number of supporting __ Linear Technology/Analog Devices App Notes, Mar 16th 2011
Lithium Battery Tester - I bought some lithium ion rechargeable batteries a while back. I was planning on using them to modify some solar powered LED spot lights. What I like about these new batteries is that they are the same size as a standard 1.5v alkaline AA cell . . . Hobby Circuit designed by David A. Johnson P.E.-February, 2012
Little More Serious Frequency Meter/CounterATtiny2313, AT90S2313 - Maximum input frequency is specified to be 30 MHz in the multi-chip configuration, and in single-chip configuration, there are both 5 MHz and 10 Mhz versions operating with 10 and 20 MHz crystals, respectively. All versions have 9 1/2 digit resolution. I have used __ Designed by Dick Cappels
Live-line Detector - Detects the presence of a live mains conductor; Minimum parts counting __ Contact Flavio Dellepiane, fladello @ tin.it
LM35 termometer - an adjustment termometer by LM35 this file simulated by Proteus 7.2 and micro program is on Bascom __ Designed by rajbai.somee.com
LM3914 Battery Monitor - This circuit should be powered by its own battery, otherwise you might get an innacurate reading. hook the to-be-monitored battery to pin 5 of the chip. __ Designed by Andy Wilson
Load Assembly Code In 8052-Basic System - 10/26/95 EDN Design Ideas: The 8052-Basic chip, a member of the popular 8051 family, is a useful µC that permits rapid prototyping and software development. The µC has an on-chip Basic interpreter. However, the interpreted Basic may be slow for certain applications. You can speed things up by coding time-critical sections of a program in assembler. Fig 1 shows a simple system that connects to a host PC running a terminal-emulation program like Vterm or Procomm. The Basic-52 Listing allows you to load assembly routines into the system's RAM. Design by Dhananjay Gadre, Inter-University Centre for Astronomy and Astrophysics, Instrumentation Lab, Pune, India
Load Monitor Alarms Above 60W - The LT2940 measures a high side current and a differential voltage, multiplies them and outputs a current proportional to instantaneous power. Bidirectional high side currents and bipolar voltage differences are correctly handled by the four-quadrant multiplier and push-pull output stage, which allows the LT2940 to indicate__ Linear Technology/Analog Devices App Note, Apr 26th 2010
Load Pulser Tests Supply's Transient Response - 04/11/96 EDN Design Ideas: Modern µPs place severe demands on the transient response of the power source. For example, intel's P6 specification stipulates an output-current capability of at least 30A/µsec while maintaining output-voltage regulation within specified limits Design by Chester Simpson, National SemiConductor, Santa Clara, CA
Load Simulator Maintains Constant Power - 04/11/96 EDN Design Ideas: The circuits in Figures 1 and 2 show how you can emulate a constant-power load for cases when a simple load resistor is unacceptable. For example, using a simple resistor as a load is unacceptable for applications that require you to accurately monitor generated or consumed power. One such application is in battery-energy measurement. You measure battery energy density (watts/hour) by measuring the total output power (W=Vxi) over time. This task is relatively simple if you use an automated system to take frequent and periodic measurements of the discharge current and battery voltage while keeping track of time. Design by Khy Vijeh, Analog Devices, Santa Clara, CA
Load Transient Response Testing for Voltage Regulators - Linear Technology AN104 __ Designed by Jim Williams - Oct 1st, 2006
Load-transient-response testing for voltage regulators - 09/28/06 EDN Technical Article: Variations occur in voltage regulators' transient loads; thus, the devices require careful evaluation and testing. Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke. He was 63.
Locate a Plastic Pipe - I used this circuit once to track down the location of a plastic pipe, buried underground. it transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2004
Lock-In Milliohmmeter - A milliohmmeter is just the tool for checking trace resistance on a printed circuit board, tracking down shorted traces, and measuring the contact resistance of a switch or connector. its the kind of tool that would come in real handy occasionally, but not often enough to justify shelling out hundreds of dollars. Wanting one anyway, I set out to make my own. it turned out to be not only an exciting project, but a true adventure of discovery as it provided a window into the workings of lock-in amplifiers __ Designed by Dick Cappels
Logic analyzer pushes microcontroller to its limit - 12/07/00 EDN Design Ideas: A simple logic-analyzer design is compatible with all versions of Windows and pushes the PIC 18C252 chip to its speed limit to achieve a 1-MHz sampling rate (Figure 1). The circuit can examine three channels of relatively low-speed logic signals that have infrequent, or sparse, transitions. The analyzer can record only 510 transitions per run, but a run can last as long as several minutes, if necessary. Applications include monitoring the i/O of an iBM keyboard or printer port, Ti-calculator intercommunication, and serial (RS-232) signals Design by Tom Lyons Fisher, Inexpensive Systems, Huntingdon, PA, and Michael Deskevich, Juniata College, Huntingdon, PA
Logic Designer & breadboarding system for Digitals - if you have never built a digital circuit before, this is where you start. Our LOGIC DESiGNER is the beginning to digital designing and can be used in 2 ways. Firstly it can be used by itself to perform counting operations in either binary or decimal or it can be combined with any of the "bread-boarding" systems currently available in all major electronics shops. __ Designed by Collin Mitchell
Logic Gates Form High-Impedance Voltmeter - 05/26/11 EDN Design Ideas: Estimate voltages across high-value resistances. You can use the circuit described in this Design idea to estimate voltages across 10- to 100-MΩ resistances. it also works for reverse-biased diodes. The common CMOS
gates in Figure 1 have an input threshold voltage in which the output swings from logic zero to logic one, and vice versa. The threshold voltage depends on the supply voltage (Figure 2). Design by Raju R Baddi, Tata Institute of Fundamental Research, Maharashtra, India
Logic offers Complementary Switch Control - 12/06/01 EDN Design Ideas: The complementary-switch controller in Figure 1 uses a few inverter gates to provide drive signals for the complementary switches. Complementary-switch configurations find wideaspread use in synchronous-rectification circuits, charge pumps, full-bridge control circuits, and other circuits. The circuit in Figure 1 provide as not only a complementary drive signal but also a deadtime delay Design by Yen-Hsu Chen, Analog Integrations Corp, Hsinchu, Taiwan
Logic Probe - An useful and easy to build Logic Probe with Pulse injector. An schematic of a "digital version" is included. __ Designed by Jose Pino
Logic probe - This logic probe uses a single CMOS
IC and shows three logic conditions, High, Low and Pulsing. in addition if the probe input is neither hI or low (the high impedance state of tri-output logic IC 's) then no LEDs will light. Power from the logic probe is taken from the logic circui __ Designed by Andy Collison
Logic Probe MkIIB - The probe uses 2 IC 's and a handful of components to indicate the state of the input on 3 LEDs while the piezo gives an audible indication of the state of the line. The input is connected to two inverters in the 4049 IC . The top one is held above mid-rail via the 1M trim pot while the bottom one is held below mid rail by the 1M/220k voltage divider __ Contact Collin Mitchell
Logic Probe uses Bicolor LED - 03/13/98 EDN ideas - (FILE
has several circuits, scroll to this one) A project posed the challenge of replacing existing analog potentiometers (used to set brightness and contrast levels]in video monitors with digitally controlled potentiometers. The different brands and models of monitors presented widely varying voltages across the potentiometers. The design. Design by Mark Shill, Burr-Brown Corp, Tucson, AZ
Logic Probe Uses Six Transistors - 12/15/10 EDN Design Ideas: Build a logic probe from discrete components. [Design ideas by Raju R Baddi, Raman Research institute, Bangalore, india Design by Raju R Baddi, Raman Research Institute, Bangalore, India
Logic Probe Uses Two Comparators - EDN-Design ideas -- 08/25/11 Build a logic probe whose voltage thresholds vary with your circuit's power supply voltage. Measurement instruments must not affect the circuits they’re measuring. A logic probe, for example, must correctly detect logic levels, and it must place no undue loads on the test circuit. The logic probe must set thresholds on automatically checking logic levels, depending on the supply voltages of the ICs it is checking. it should also not cause the checking circuit to function incorrectly. Design by Vladimir Rentyuk, Zaporozhye, Ukraine
Logic probe with 7-segment display - Logic probe with 7-segment display based on 74LS00 and 74LS47__
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