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Tester or Measurement (Instrument) Circuits

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Last Updated: November 30, 2017 02:27 PM

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747




Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

Low-Component-Count Zero-Crossing Detector is Low Power -  03/14/13  EDN Design Ideas:  A simple opto-coupled circuit produces a logic level output signal synchronized to the power line.  There are many circuits published showing zero-crossing detectors for use with 50- and 60-Hz power lines.  Though the circuit variations are plentiful, many have shortcomings.  This Design idea shows a circuit that uses only a few commonly available parts and provide as good performance with low power consumption.  in the circuit shown in Figure 1, a waveform is produced at VO with rising edges that are synchronized with the zero crossings of the line voltage, VAC.  The circuit can be easily modified so that it produces a falling-edge waveform that is synchronized with VAC.   __ Circuit Design by Carlos Castro-Miguens

Low-Cost 50MHz Frequency Meter -  it features an LCD readout, auto-ranging and two resolution modes.  And it can be run from a plugpack or battery operated.__ SiliconChip

Low-Cost 50MHz Frequency Meter; Mk.2 -  This update of our very popular compact 50MHz Frequency Meter now has an internal battery pack or can run from a DC plugpack supply.  it also incorporates a 10kHz rounding mode to enable 36MHz R/C transmitters using pulse position modulation (PPM) to be measured with an unambiguous reading.__ SiliconChip

Low-cost active load draws constant battery power -  04/13/00 EDN Design Ideas:  Unlike nickel-metal-hydride and lithium-ion rechargeable batteries, the discharge voltage of alkaline batteries is not constant and tends to vary from 1.5 to 0.8V per cell.  Alkaline-battery manufacturers specify the discharge life of their batteries under constant powerloads.  Because of the varying discharge voltage, you can't simply connect a load resistor to the cells to verify or measure power profiles without incurring a lot of error in your measurements.  The circuit in Figure 1draws a constant power from the battery pack.  Thus, as the battery voltage decreases, the load current increases.  A single potentiometer allows a user to set the desired wattage draw.  The circuit is simple and inexpensive to build.   __ Circuit Design by Doug Farra

Low-Cost Anemometer Fights Dust -  08/30/01  EDN Design Ideas:  As higher levels of power dissipation underscore the need for cooling, andfans are finding their way into small electronic enclosures.  The dust that fans pull into these enclosures can, however, cause major problems for high-reliabi __ Circuit Design by Jim Christensen, Maxim Integrated Products, Sunnyvale, CA

Low-cost BER tester measures errors in low-data-rate applications -  12/05/05  EDN Design Ideas:  You don't need an expensive pattern generator to produce a PRBS (pseudorandom-bit-sequence] signal for making elementary BER (bit-error-rate] measurements in low-data-rate continuous-transmission systems __ Circuit Design by Cedric Mélange, Johan Bauwelinck, Jo Pletinckx, and Jan Vandewege, Ghent University, Ghent, Belgium

Low-cost current Monitor tracks high DC currents -  03/01/07  EDN Design Ideas:  Oscillator's output tracks current as it varies inductor's core characteristics __ Circuit Design by Susanne Nell, Breitenfurt, Austria

Low-Cost Hearing Aid -  Commercially available hearing aids are quite costly.  Here is an inexpensive hearing aid circuit that uses just four transistors and a few passive components.  On moving power switch S to ‘on’ position, ...__ Electronics Projects for You

Low-Cost Hearing Aid -  This hearing aid circuit offers the advantages of high sensitivity, low current consumption, low cost and light weight. Audio signals are sensed by the condenser microphone and amplified by two op-amps built...__ Electronics Projects for You

Low-Cost LPG Leakage Detector -  The circuit for an LPG leakage detector is readily available in the market, but it is extremely expensive and usually based on a microcontroller (MCU).  This project presents a low-cost circuit for an LPG detector that you can build easily.  The main objective of the circuit is to detect LPG leakage anywhere. At the heart of the circuit is dual comparator IC LM393 (IC 2).  it is used to compare two different voltages, in this case reference voltage and MQ-6 gas sensor output voltage__ Electronics Projects for You

Low-Cost PCO Billing Meter -  The circuit presented here can be used in PCOs for displaying the actual bill.  The comparative disadvantages of the presented circuit are as follows: 1.  The calculator used along with this circuit...__ Electronics Projects for You

Low-Cost PC-to-I2C Interface for Debugging -  Tracking down problems in circuits which are programmed via an i2C bus can be tricky and time-consuming, unless you take advantage of a debugging program running on a PC.  Here's a low-cost, easy-to-build printer port to i2C interface designed to work with the Philips/NXP debugging program URD312.exe.__ SiliconChip

Low-cost relative-humidity transmitter uses single logic IC -  11/08/01 EDN Design Ideas:  The low-cost percentage-relative-humidity radio transmitter in Figure 1 operates in a cold-storage warehouse for vegetable storage at temperatures of 1 to 5°C.  it is generally difficult to collect such data from a low-temperature area with high humidity and low illumination.  The transmitter design is simple  it uses a readily available, capacitor-type percentage-relative-humidity se __ Circuit Design by Shyam Tiwari, Sensors Technology Ltd, Gwalior, India

Low-cost RF sniffer finds 2.4-GHz sources -  11/23/06 EDN Design Ideas:  Locate interference sources in the iSM band __ Circuit Design by Vladimir Dvorkin, Linear Technology Corp, Milpitas, CA

Low-Cost Universal Dual Channel Audio Checking & Troubleshooting Tool -  Frequently, we are in need to do audio troubleshooting of electrical and electronic components, installations and equipment. E.g.  we may need to check, test and evaluate:microphones loudspeakers headphones audio filters preamplifiers the...__ Electronics Projects for You

Low-Drift High-Impedance JFET DC Voltmeter -  The voltmeter shown in the schematic diagram below has very high impedance.  The range selector uses conventional voltage divider resistors, but since the following pre amplifier uses JFET, the divider can be designed using very high resistance series resistors.__ 

Low-Power timer -  Low power timer.  it can operate with a CR2032 litium battely.   __ Designed by The Electronic Lives Manufacturing-presented Chan

Low-Power voltage-to-frequency converter makes a wireless probe for testing an inductive power supply -  05/26/05  EDN Design Ideas:  inductive pickup measures low-power circuit's supply __ Circuit Design by Francis Rodes, Eliane Garnier, and Salma Alozade, ENSEIRB Talence, France

Low-Resistance Continuity Tester -  Using this circuit you can check continuity of low-resistance paths such as PCB tracks, small coils, intermediate-frequency transformers (iFTs) and low-resistance transformers.  However, you can’t check semiconductors with this tester.__ Electronics Projects for You

Low-Voltage Continuity Tester -  Several simple circuits were tried -a lamp, battery and probes still demanded the attention of the eyes; replacing the lamp with a buzzer was more successful but needed some three to four volts and gave no indication of a series semiconductor.   __ Designed by Tony van Roon  VA3AVR

LT2940 Power & Current Monitor-Video Product Brief -  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, Kevin B. Scott-Strategic Marketing Engineer Feb 11th 2010

LT5528 WCDMA ACPR & AltCPR Measurements -  AN99 ACPR (adjacent channel power ratio) and AltCPR (alternate channel power ratio) are both measures of spectral regrowth.  They are important performance metrics for digital communication systems that use, for example, WCDMA (wideband code division multiple access) modulation.  __ Linear Technology/Analog Devices

LT6110-Cable/Wire Drop Compensator with LT1965 Linear Regulator -  Click Here For A Ready To Run LTspice Circuit Demonstration The LT®6110 is a precision high side current sense with a current mode output, designed for controlling the output voltage of an adjustable power supply or voltage regulator.  This can be used to compensate for drops in voltage at a remote load due to resistance __ Linear Technology/Analog Devices App Note, Greg Zimmer Oct 17th 2013

LTC Design Note 510: Measure RH with instrumentation-grade system Monitor -  04/30/14  EDN Design Ideas:  An accurate, modern system monitor chip senses humidity the old-fashioned way.  Because much can be deduced about a physical system by measuring temperature, it is by far the most electronically measured physical parameter.  Selecting a temperature sensor involves balancing accuracy requirements, durability, cost, and compatibility with the measured medium.  For instance, because of its low cost, a small-signal transistor such as the MMBT3904 is an attractive choice for high volume or disposable sensing applications.  Although such sensors are relatively simple, accurate temperature measurement requires sophisticated circuitry to cancel such effects as series resistance.   __ Circuit Design by Leo Chen

LTC1392 Monitors System Temperature & Multiple Supply Voltages & Currents -  DN149 Design Notes__ Linear Technology/Analog Devices

LTC1392: Temperature & Voltage Measurement in a Single Chip -  DN106 Design Notes__ Linear Technology/Analog Devices

LTC2057 Differential Thermocouple Amplifier -  The LTC2057 is a high voltage, low noise, zero-drift operational amplifier that offers precision DC performance over a wide supply range of 4.75V to 36V or 4.75V to 60V for the LTC2057HV.  Offset voltage and 1/f noise are suppressed, allowing this amplifier to achieve a maximum offset voltage of 4μV and a DC to 10Hz input __ Linear Technology/Analog Devices App Notes, Jun 19th 2013

LTC2974 Demonstration Video -  The LTC2974 is a quad, digital power-supply monitor, supervisor, sequencer, and margin controller.  Supervisory functions include over and under threshold limits for current, voltage and temperature on four output channels as well as OV/UV threshold limits for a single input channel.  Programmable fault response allows the power __ Linear Technology/Analog Devices App Note, Mar 13th 2013

LTC2974 Quad Power System Manager with EEPROM (Digital Power Manager) Video Product Brief -  The LTC®2974 is a quad, digital power-supply monitor, supervisor, sequencer, and margin controller.  Supervisory functions include over and under threshold limits for current, voltage and temperature on four output channels as well as OV/UV threshold limits for a single input channel.  Programmable fault response allows the __ Linear Technology/Analog Devices App Note, Chris Gobok-Product Marketing Engineer Jan 22, 2013

LTC2990 I2C Temperature, Voltage & Current Monitor-Video Product Brief -  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 Note, Chris Gobok-Product Marketing Engineer Feb 23, 2011

LTC2990-Motor Protection/Regulation -  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. __ Linear Technology/Analog Devices App Note, Oct 26th 2010

LTC2991 Octal I2C Voltage, Current & Temperature Monitor-Video Product Brief -  The LTC®2991 is used to monitor system temperatures, voltages and currents.  Through the i2C serial interface, the eight monitors can individually measure supply voltages and can be paired for differential measurements of current sense resistors or temperature sensing transistors.  Additional measurements include internal temperature __ Linear Technology/Analog Devices App Note, Chris Gobok-Product Marketing Engineer Sep 13th 2011

LTC4151 Interfaces with Isolation Barrier in-48V ATCA Application -  For negative applications, ViN is measured with respect to the GND pin and the GND pin does not have to be at 0V.  The i2C isolation is required since the i2C pins are also referenced to the GND pin.  For OV and UV, ADiN could be used to measure a voltage between 0V and 2.048V, and the value can be compared to an OV and/or UV threshold in the microcontroller (stored in register) to determine if there is a fault.  Note__ Linear Technology/Analog Devices App Note, Jan 19th 2011

LTD-Low Cost Telemetering Device -  The ATmega8 microcontroller-based Low-Cost Telemetry Device (LTD) is an efficient telemetry keyer.  The LTD measures the voltage levels of up to four analog channels via its on-chip 10-bit ADC, converts the measurements to numbers, and then sends the data in Morse code to an external transmitter and to an attached RS-232 terminal.  it can be set up either by the RS-232 terminal, in which case, a character string, such as transmitter iD, can can be sent, or it can be set up with only jumpers to ground.  Parts count is very low, in part because the ATMega8's internal clock is used for timing.  Jeff Heidbrier came up with the idea for this project, built the prototype, and colaborated with me on the design of the LTD and this documentation. 
 __ Designed by Dick Cappels

Lua Barometer WiFi ESP8266 -  Glass & Brass barometer is precise digital wifI barometer with pressure sensor BMP085 or BMP180 and wifI module ESP8266.  it's a miniature web server.
By mapping ports of your router, you can connect to it from anywhere on the world.  The barometer uses Lua software and
trendy vector graphics format SVG.  The barometer is particularly interesting for its graphic design.  in terms of program, this is simple.
Thanks to this, barometer is quite fast and stable, which was my goal. __ Designed by © Pavel Janko

Lua Hygrometer WiFi ESP8266 -  This hygrometer is digital wifI hygrometer.  it's a miniature web server.
By mapping ports of your router, you can connect to it from anywhere on the world.  This hygrometer uses Lua software and
trendy vector graphics format SVG.  Hygrometer is quite fast and stabil. __ Designed by © Pavel Janko

Lux Meter -  This is a simple Lux Meter that is suitable for beginners.   __ Designed by The Electronic Lives Manufacturing-presented Chan

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