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Tester or Measurement (Instrument) Circuits

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Last Updated: November 22, 2021 02:42 PM
Circuits Designed by Dave Johnson, P.E. :

Medical Fluid Detector  -  A simple 40KHz 12v peak to peak square wave signal generator, using a 555 timer oscillator, was fed to the metal needle and the whole vertical indexing system, which was electrically isolated from everything else.  On the receiver end, a copper foil electrode, which was designed to fit snugly on the bottom of a plastic cup, acted as a holder for the fluid container. . . . Dave Johnson, Lubbock TX-DC Magazine - Issue 11 July 2010

Measure Button Battery Cell's Internal Resistance  -  The open cell voltage of a small silver oxide button cell battery remains very close to 1.5 volts over most of the life of the cell.  However, there is a relationship between battery health and the internal resistance of the cell.   This circuit when used . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006

 

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-778-8407




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

Measure Software-Execution Timer -  03/17/94 EDN Design Ideas:  Especially heLPFul for developing real-time application programs, the circuit in Fig 1 plugs into a PC printer port and measures the execution time of a piece of software.  The CD4536 is a 16/24-bit binary counter with a built-in oscillator.  This counter has an 8-bit prescaler, which the chip bypasses if the 8_BY pin is high.  When this is the case, the CD4536 is a 16-bit counter, and its A through D inputs select which bit is connected to output DO.  if the 8_BY pin is low, the CD4536 is a 24-bit counter and the inputs select Design by Yongping Xia, EBT Inc, Torrance, CA

Measure Solar Radiation On an Ubuntu Server -  A device used for measuring daily insolation has been designed using the Ubuntu Server.  The total solar radiation is measured by a Kipp & Zonen CM11 pyranometer.  The EMF output of 5.14 uV/W/m2 is fed to the 24-bit resolution Delta-Sigma A/D converter, LTC2400.  The microcontroller circuit built with a PIC 18F2550 controls the A/D converter and provides one second time base for data sampling period.  The insolation is computed by accumulated summation of the converted data in a whole day __ Designed by Wichit Sirichote

Measure temperature in remote locations -  10/12/00 EDN Design Ideas:  The compact and low-power temperature-to-frequency converter in Figure 1 is ideally suited for measuring temperature in remote locations.  An AD22100A temperature sensor generates a voltage proportional to the ambient temperature.  This voltage then drives an AD7740 VFCPDF contains multiple circuits, scroll to find this circuit-- [Helen Stapleton, Analog Devices, Limerick, ireland] Design by Helen Stapleton, Analog Devices, Limerick, Ireland

Measure two resistive sensors or multiple switches with a single Schmitt -  10/16/13  EDN Design Ideas:  Many of the sensors capturing information from the world around us are resistive.  A few examples are NTC, PTC, LDR & contact sensors.  if we convert the resistance of the sensors into frequency or pulse duration, these parameters can be measured by most MCUs, without needing an ADC.   Design by Petre Petrov

Measure voltages up to 20,000 V with this home built meter -  Many of the projects on this site deal with high voltages ranging from a few to several kilovolts.  Unfortunately, traditional multimeters can measure voltages up to only about 1, 000 volts leaving many of us to crudely estimate voltages by spark gap distances.  This project utilizes a simple voltage divider network enabling the measurement of several kilovolts on a stand-alone digital voltmeter.   __ Designed by Greg Miller

Measure Zener Voltages & Test LEDs -  06/10/10  EDN Design Ideas:  You can use this circuit to measure zener voltages as high as 40V.  To measure a zener diode's breakdown voltage, you need a dc voltage source whose voltage exceeds that of the zener voltage.  in Figure 1, resistor RSER provide as voltage drop between ViN and VZEN.  in any case, ViN should exceed VZEN.  Resistor RSER must provide current, iZEN, that can keep the zener diode in reverse breakdown.  That is, the current must be more than iZEN-iZENMiN and less than iZEN-iZENMAX.  You also need to consider the current that flows through the load.  Otherwise, VZEN will be unregulated and less than the nominal breakdown voltage.  Also, the power that the zener diode dissipates should not exceed the manufacturer's specifications.  Except for the value of iZEN-iZENMiN, all necessary data appears in zener-diode data sheets.   Design by Vladimir Oleynik, Moscow, Russia

Measurement & Control Collection -  AN45 A variety of measurement and control circuits are included in this application note.  Eighteen circuits, including ultra low noise amplifiers, current sources, transducer signal conditioners, oscillators, data converters and power supplies are presented.  The circuits emphasize precision specifications with relatively simple configurations.  __ Linear Technology/Analog Devices

Measurement and Control Circuit Collection -  Linear Technology AN45 __ Designed by Jim Williams - Jun 5th, 1991

Measurement methods -  Application Note__ MiniCircuits.com

Measurement techniques help hit the 1-ppm mark -  04/26/01  EDN Technical Article: Part 2 of this series on the design of a 20-bit DAC discusses the all-important techniques for testing the performance-linearity, settling time, and noise-at such minuscule data levels.  See Part 3 in the next issue.   Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Measurements on CCFL-drivers pose tricky problem -  05/09/96  EDN Technical Article: Obtaining reliable efficiency data for CCFL circuits presents difficult measurement problems.  The accuracy required in the high-frequency ac measurements is uncomfortably close to the state of the art.   Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Measures Capacitance or Inductance -  10/21/10 EDN Design Ideas:  Use instruments you already have and a few equations when you don’t have a capacitance meter.   Design by Jim McLucas, Broomfield, CO

Measures diesel's rotations per minute -  03/04/99 EDN Design Ideas:  (Scroll to find this one) The circuit in Figure 1 uses a Dallas Semiconductor DS1820 one-wire digital thermometer in a multipoint temperature-measurement system.  The DS1820 sensor allows distributed temperature measurement and uses only one wire for both data communication and the power supply.  You can easily connect the one-wire interface to a µC (in this example, a PIC 16C63).  The application accommodates as many as 16 DS1820 sensors in a 100m-long network, dubbed MicroLAN by Dallas.  Unfortunately, with such long wires near high-current power cables, inductively coupled high-voltage peaks can cause µC latch-up, because the transient-voltage suppressor, D1, cannot limit the line voltage below 9.8V.  The interface circuit in Figure 1 prevents such faults.   Design by David Magliocco, CDPI, Scientrier, France

Measures True-Rms & Average Value -  09/26/02  EDN Design Ideas:  The circuit in Figure 1 measures both the true-rms value and the rectified average value of an ac signal.  This design uses two low-cost ICs  in SOIC  packages and consumes only 180 µA of quiescent current.  Operating from a single 5V Design by Charles Kitchin and Lew Counts, Analog Devices, Wilmington, MA

Measuring 16-bit settling times: the art of timely accurac -  11/19/98  EDN Technical Article: Accurately measuring the settling time of a 16-bit DAC and its output amplifier is an art form.  One measurement technique borrows from the design of a classic sampling oscilloscope and provide as reliable results.  Three other measurement approaches produce results that closely agree with each other.   Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Measuring Acceleration using a PIC Microcontroller (ADXL202 + PIC16F84A) -  Motivation and Audience:Motivated by one of the article from circuit cellar, I want to trace the author's steps to see how the G-Force machine work.  The author wrote an article on how to build a machine, that measure acceleration using a PIC  16F84 and a acceleration sensor.  Audience will require expience in programming PIC  Microcontroller (intro to microcontroller) and basic electrical background __ Designed by dn26 @ drexel.edu

Measuring Gig/Tera Ohm Resistors -  The method was created by me, many years ago.  This Article Created here: "Nov 11 2008"  I decided to post this now, because of a request on my Chemelec Forum.   __ Designed by G.L. Chemelec

Measuring Input & Output Impedance -  From the AC impedance triangle, the input or output impedance of a two terminal network can be determined by measuring the small signal AC currents and voltages.  For the input, the voltage is measured across the input terminals and the current measured __ Designed by Andy Collison

Measuring Motor Speed Uses Low-Cost Components -  11/08/07  EDN Design Ideas:  A microcontroller-based circuit provide as both an LCD readout and an analog motor-speed output Design by R García-Gil, J Castelló, and JM Espí, Escola Tčcnica Superior d’Enginyeria, University of Valencia, Spain

Measuring precision-amplifier settling time -  10/28/99  EDN Technical Article: Obtaining a reliable settling-time measurement is difficult and requires a careful approach and an experimental technique.  You can use new circuits to test the 30-nsec settling time of a precision wideband amplifier.   Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Measuring RF Voltages with a VOM -  Simple diode detectors may be constructed to enable ordinary VOMs to measure RF voltages ranging from a few hundred millivolts to the breakdown voltage of the diodes.  Figure 1 shows two types of simple detectors, a series detector and a shunt detector.  The choice is somewhat arbitrary but the shunt circuit is convenient when using microwave diodes designed to be directly connected to ground.  Construction is not critical but the components to the left of the dotted line should have short leads.  A termination resistor (such as 50 ohms) may be added across the input for measuring the loaded output voltage of amplifiers and signal sources.   __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Measuring self resonant frequency -  Coilcraft RF Magnetics App Note- __ Designed by Coilcraft Power Magnetics Application Note

Measuring sensitivity of transponder coils -  Coilcraft RF Magnetics App Note- __ Designed by Coilcraft Power Magnetics Application Note

Measuring Seven RTD Temperatures with One Reference Resistor & One Reference Current -  The LTC2408 is 8-channel 2.7V to 5.5V micropower 24-bit A/D converters with an integrated oscillator, 4ppm iNL and 0.3ppm RMS noise.  They use delta-sigma technology and provide single cycle digital filter settling time (no latency delay) for multiplexed applications.  The first conversion after the channel is changed is always __ Linear Technology/Analog Devices App Note, Mar 30th 2010

Measuring Switching Regulator Noise -  The universal application of switching regulators, combined with the powered systems potential for supply noise sensitivity, mandates the need for a reliable noise measurement technique.  Actually, switching regulator "noise" isn't really noise at all, but coherent, high frequency residue directly related to the regulators switching.  __ Linear Technology/Analog Devices App Note, Jim Williams-Staff Scientist Jun 15th 2009

Measuring the Capacity of a Battery -  Find out how to measure the capacity of a battery.   __ Designed by REUK-Renewable Energy UK website

Measuring the Charging & the Discharging Current Of the Battery -  introduction When we work with rechargeable battery it is useful to have the following functions:* measuring the charging current * measuring the discharging current * measuring the voltage over the batteryBut in order to...__ Electronics Projects for You

Measuring the speed of light with an infrared LED / photodiode (TDOA) -  infrared based electronic circuit diagrams / circuit schematics __ Designed by M. Gallant

Measuring wideband-amplifier settling time -  08/12/10  EDN Technical Article: A novel circuit lets you measure output settling to 0.1% in 2 nsec.   Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Medical Fluid Detector  -  A simple 40KHz 12v peak to peak square wave signal generator, using a 555 timer oscillator, was fed to the metal needle and the whole vertical indexing system, which was electrically isolated from everything else.  On the receiver end, a copper foil electrode, which was designed to fit snugly on the bottom of a plastic cup, acted as a holder for the fluid container. . . . Dave Johnson, Lubbock TX-DC Magazine - Issue 11 July 2010

Medical timer warns when pills are due -  05/10/01 EDN Design Ideas:  Some people need to take medication at precise, regular intervals.  When you're in a hospital, a medical staff is present to ensure that you take your medication on time.  But when you're taking medication at home, you must frequently look at the clock-a clear annoyance.  When my wife was pregnant, she needed to take medication every two hours from 8 am to 10 pm.  To help her time the two-hour intervals, I built the battery-powered circuit in Figure 1.  The circuit derives its power from a 9V PP3 battery.  All the ICs  are CMOS -based; the low power consumption of the circuit allows one-week autonomy.  When you press the start button, BP1, a two-hour delay commences.   Design by J Terrade

Medicine-Time Reminder -  We are all so busy with our daily lives that we forget to take our medicines on time, which can have several ill effects on our health.  The circuit described here...__ Electronics Projects for You

Medium & Very High Quality Two Tone Generators -  For Transceiver testing __ Designed by VK5JST / VK5TR

Mercury Battery Replacement -  I have recently been trying to restore a Radector radiation survey meter, vintage 1950s.  This instrument uses a 10 atmosphere argon filled ion chamber as the radiation detector and has an electrometer type vacuum tube sealed inside the chamber.  The design is simple and, for the time, quite elegant.  Unfortunately it uses three different mercury batteries.  One large 1.35V for the filament power, one smaller 1.35V for bias and one 5.4V for the plate supply of the electrometer tube.  Because of the design, the calibration depends on the voltage of the batteries staying constant over the useful battery life.  Mercury batteries maintain a very constant voltage over most of their life, a characteristic NOT shared by present day alkaline cells or any other easily obtained batteries.   __ Designed by Craig Taylor

Mercury battery replacement -  Many old cameras and other devices used mercury batteries, which are no longer available.  Here is an analysis of the problem, and a few solutions.   __ Designed by Manfred Mornhinweg

Mercury Battery replacement for Antique Instruments -  I have recently been trying to restore a Radector radiation survey meter, vintage 1950s.  This instrument uses a 10 atmosphere argon filled ion chamber as the radiation detector and has an electrometer type vacuum tube sealed inside the chamber.  The design is simple and, for the time, quite elegant.  Unfortunately it __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Metal Detector -  This circuit detects metal and also magnets.  When a magnet is brought close to the 10mH choke, the output frequency changes.  __ 555-Timer

Metal Detector -  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

Metal Detector -  A single chip metal detector with a range of a few inches.  This is useful for decting nails or screws in walls and floors, or for locating buried mains cable.   __ Designed by Andy Collison

Metal Detector 1 MHz -  Schematic only __ Designed by va3iul

Metal Detector 1 MHz 3xBJT -  Schematic only __ Designed by va3iul

Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.

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Test Equipment:  #'s - A        B - D        E - G
H - L        M - O        P - S        T - Z


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