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Tester or Measurement (Instrument) Circuits

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


Last Updated: October 24, 2017 02:55 PM
Circuits Designed by Dave Johnson, P.E. :

Monitor Clear Fluids -  This circuit detects when a clear fluid is inside a piece of clear plastic tubing.  it can be used for fluid level control and monitoring. . . Circuit by David Johnson P.E.-May, 2012

Monitor Water Seepage -  A while back I received a request from a company who needed a water seepage detector.  They wanted a device that ran on 24vac and detected water using a fully isolated circuit.  They wanted a circuit which switched off 24vac to a load when water was detected . . . Hobby Circuit designed by Dave Johnson P.E.-January, 2011

Monitors AC Current -  This circuit uses a small AC current transformer from Magnetek to produce an isolated voltage proportional to the AC current in the primary winding.  The transformer contains a single turn primary with a low 0.001-ohm resistance.  it can easily handle 30 . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

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:

Monitor & balance large lithium-Ion batteries -  09/03/07  EDN Design Ideas:  Using a microcontroller's built-in ADC to measure cell voltage and temperature, this lithium-ion cell monitor equalizes the cell voltage and signals alarm conditions __ Circuit Design by Daniel Gomez-Ibanez, Woods Hole Oceanographic Institution, Woods Hole, MA

Monitor 15 contacts with one PIC input -  EDN Design Ideas:  10/27/2014     Take advantage of a microcontroller’s feature set to simplify switch & contact interface __ Circuit Design by Benabadji Noureddine, 10/27/2014

Monitor a differential paIR for valid & fault conditions -  EDN Design Ideas:  02/09/2015    Monitor the state of a differential communications line with This design idea     . __ Circuit Design by Budge Ing

Monitor AC-Power Loss -  11/24/99 EDN Design Ideas:  The circuit in Figure 1 provide as a simple, nonvolatile means of monitoring critical ac-power failures.  Monitoring the power is important in such systems as heating and refrigeration, in which damage can occur if the ac power goes down for an extended period.  The circuit in Figure 1 requires little power from the ac-power system.    __ Circuit Design by Dennis Eichenberg, Parma Heights, OH

Monitor Alarm & Indicator Display Multiple Deviation Boundaries -  22-April-10 EDN Design Ideas:  Use a microcontroller and its ADCs to indicate process errors.    __ Circuit Design by William Grill, Riverhead Systems, Lenexa, KS

Monitor Battery Voltage -  11/21/96 EDN Design Ideas:  The circuit in Figure 1 monitors four NIC d rechargeable batteries and causes the LED to flash if the voltage of the batteries goes lower than 4V.  The circuit consumes only 8 mA of current under normal operating conditions.   IC 1 is an eight-pin IC that includes an op amp, a comparator, and a 1.2V zener diode.  The zener diode connects to the negative input of the comparator in the IC as a reference.  R6 and R7 divide the battery voltage __ Circuit Design by Yongping Xia, Philips Lighting Electronics Co, Torrance, CA

Monitor Clear Fluids -  This circuit detects when a clear fluid is inside a piece of clear plastic tubing.  it can be used for fluid level control and monitoring. . . Circuit by David Johnson P.E.-May, 2012

Monitor Conserves Battery Energy -  04/19/12  EDN Design Ideas:  Many battery-powered systems require a visual indication when the battery needs replacement.  LEDs often serve as the indicator, but they can draw as much as 10 mA of current.  This excessive current drain unduly accelerates the battery’s discharging and cu __ Circuit Design by Brian Huffman, Linear Technology Corp, Milpitas, CA

Monitor for 6V/12V Batteries -  Rechargeable batteries of 6V and 12V are used in a large number of applications.  it is imperative that these are maintained properly to get maximum life out of them.  Further, their...__ Electronics Projects for You

Monitor high-side current without an external supply -  03/01/01 EDN Design Ideas:  Typical high-side current-sensing circuits require a dc source that is 2.5 to 13V greater than the V+ high-bus voltage (Figure 1 ].  Generating this supply is painful in many situations.    __ Circuit Design by Vijay Damle

Monitor Leakage Current -  06/21/01 EDN Design Ideas:  The residual-current circuit breaker in Figure 1 continuously monitors the supply lines for any leakage current and immediately disconnects the supply if necessary.  Load-supply wires, both live and neutral, pass through the magnetic core of the CR4311-5 __ Circuit Design by Sharath Kumar, Gemplus R&D Centre, Dubai, United Arab Emirates

Monitor Multiple Contact Closures -  02/15/96 EDN Design Ideas:  The simple circuit in Figure 1 monitors multiple (15) pairs of relay contacts and provide as visual and electronic indications of contact closures.  A series-connected LED, current-limited by a 2.2-kOhm resistor, provide as a visual indication of each contact closure and remains lit while the contact is closed.  The circuit comprising a current mirror (Q1 and Q2) and comparator IC 1 provide as an electronic indication (a pulse at IC 1's output) of each contact closure.    __ Circuit Design by Richard McGillivray, Grey Bruce Regional Health Centre Owen Sound, Ontario, Canada

Monitor quad supply for PCI systems -  08/19/99 EDN Design Ideas:  Many modern systems operate with multiple power supplies that must meet tight tolerances to accommodate high-end µPs and peripherals.  For instance,  __ Circuit Design by Roger Zemke

Monitor Water Seepage -  A while back I received a request from a company who needed a water seepage detector.  They wanted a device that ran on 24vac and detected water using a fully isolated circuit.  They wanted a circuit which switched off 24vac to a load when water was detected . . . Hobby Circuit designed by Dave Johnson P.E.-January, 2011

Monitors AC Current -  This circuit uses a small AC current transformer from Magnetek to produce an isolated voltage proportional to the AC current in the primary winding.  The transformer contains a single turn primary with a low 0.001-ohm resistance.  it can easily handle 30 . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Monolithic IC for 100MHz RMS/DC Conversion -  AN22 AN22 details the theoretical and application aspects of the LT1088 thermal RMS/DC converter.  The basic theory behind thermal RMS/DC conversion is discussed and design details of the LT1088 are presented.  Circuitry for RMS/DC converters, wideband input buffers and heater protection is shown.  __ Linear Technology/Analog Devices

Morse Monitor -  Here is a little novelty circuit that I found in some time ago, dug out of the archives after an E-mail request.  The circuit was given to me by the late G8ABZ in about 1967 as a circuit that will oscillate first-time every-time.  I have added a diode detector so that it will generate a sound when a transmitter is keyed. __ Designed by Harry Lythall-SM0VPO

MOSFET Current Sensing -  Method of mirror current sensing a MOSFET __ Designed by Richard Torrens

MOSFET Tester -  This is a variation on the astable multivibrator. Circuit was recently developed to test for N-mosfets (the power kind e.g irf830).   I don’t claim circuit can test all bad mosfets or all fault mosfet conditions. if mosfet is working it will operate in the astable multivibrator circuit causing the LED to flash. __ Contact IQ Technologies

MOSFET Tester -  This testing procedure is for use with a digital multimeter in the diode test-range with a minimum of 3.3  volt over d.  u.  t. (Tony van Roon's diode-under-test).  if your multi-meter is less than that it will not do the test.  Check your meter manual for the specs.   __ Designed by Tony van Roon  VA3AVR

MOSFET tester for N-type MOSFET transistors -  PIC 16F688 reads data from DS1820 sensor through RA5 port, and the computed temperature is sent to the LCD through RC0-RC3 ports. it means the data transfer from PIC  to LCD is achieved in 4-bit mode. The Register Select (RS) and Enable (E) signals for LCD are provided through ports RC4 and RC5. The Read/Write pin of the LCD is grounded as there is no data read from the LCD in this project. The contrast adjustment of LCD is done with the 10K potentiometer shown in the circuit diagram.__ 

Motion Controlled Blinking Eyes -  13-May-14 -Design News:   This is Mark iI of my Animatronic Eyes, which was created for someone who wanted to animate a rock sculpture.  The eyes themselves were made with plastic Easter egg tops, which fit perfectly as eyelids over ping pong balls.  The problem there becomes one of mounting and alignment.  in this version,__  Gadget Freak-Case #254

Motion Detector Alarm -  This motion detector alarm circuit can detect a moving person from a distance of 1 meter.  it uses a Dual IR Transmitter-Receiver module HOA1405.  When the sensor detects the reflected IR rays, Alarm will sound for 2 minutes.  The circuit can be modified for various applications including AC operated alarm systems.  Motion __ Designed by D Mohankumar

Motion Sensing LED -  Hack your box of chocolates with arduino iDE and ATtiny13. __ Contact Jameco Electronics

Motion Sensor for Security Light -  Here is a system based on PiR motion detector module BS1600 (or BS1700) that can be used for security or corridor lighting in power-saving mode.  The 12V DC power supply required...__ Electronics Projects for You

Motion Sensor Light Switch -  3-Sep-15 -Design News:   Are there light switches in your home that aren't as conveniently located as you would like? This laser-based switch decoder and driver allows for flexible control of those lights located in less than ideal places.  I live in an apartment.  My kitchen is boring and can be accessed from either end of __  Gadget Freak-Case #272

Motor Accu Ladder -  Article is in Dutch __ Designed by Jan Hammer

Motor Monitor with Breaker -  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

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

Motor Protection/Regulation-LTC2991 -  The LTC2991 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, Sep 7th 2011

Motorcycle Low Voltage Warning -  This circuit is connected to your motorcycle.  it's tapped into a circuit thats only powered with the key "ON".  if you turn the bike off with the kill-switch and leave the key on, as you know, the headlight will stay on and quickly drain the battery.   __ Designed by Tony van Roon  VA3AVR

Motorola 68HC11 Evaluation Board -  Build a low-cost evaluation board for Motorola 68HC11.  Downloadable BUFFALO V3.4 to 32kB SRAM for learning __ Designed by Wichit Sirichote

Moving-coil meter measures low-level currents -  3-Mar-05 EDN Design Ideas:  Although an analog moving-coil meter may lack the resolution and accuracy that a digital readout provide as, a meter remains the display of choice for certain applications.  A digital readout simply cannot provide information about a measurement's rate of change, and tracking a reading's trend is easier on an analog meter __ Circuit Design by Kevin Bilke, Maxim Integrated Products Inc, Hook Hants, UK

Multi wire cable tester -  A multI wire cable tester with a separate LED for each wire.  Will show open circuits, short circuits, reversals, earth faults, continuity and all with four IC 's.  Designed initially for my intercom, but can be used with alarm wiring, CAT 5 cables and more __ Designed by Andy Collison

Multichannel Temperature Monitor -  03/04/04 EDN Design Ideas:  You can use an ADT7461 single-channel temperature monitor, an ADG708 low-voltage, low-leakage CMOS 8-to-1 multiplexer, and three standard 2N3906 PNP transistors to measure the temperatures of three separate remote thermal zones (F __ Circuit Design by Susan Pratt, Analog Devices, Limerick, Ireland

Multichannel Visual Thermometer -  Temperature of some electronic components used in a device may rise unexpectedly and these might get damaged.  This multichannel visual thermometer can indicate the problem through glowing LEDs.  Since transistors are...__ Electronics Projects for You

Multi-decade current Monitor the epitome of simplicity -  EDN Design Ideas:  02/06/2017    This DI will likely make the simplest piece of T&M gear on your bench __ Circuit Design by Nick Cornford

Multimeter As Lightning Detector -  Most digital multimeters have a sensitivity of 200 mV and in input impedance of 10 MR.  With this information you can calculate that at full scale there will be a current of 20 nA (nano-ampères).  in reality you have a very sensitive ammeter in your hand.  Now that we know this, it becomes a mission __ Designed by Karel Walraven – © Elektor Electronics Magazine

Multimeter on ATmega8 for power supply unit -  This multimeter was designed to measure output voltage and current in a PSU, where the current sense shunt resistor is connected in series with load at the negative voltage rail.  it needs only one supply voltage that can be acquired from main PSU.  __ 

Multipurpose Listening Device -  This circuit can detect very faint, remote sounds with a good clarity.  it is useful in large conference halls, auditoria, cinema halls, lecture rooms in colleges, etc.  The circuit can be...__ Electronics Projects for You

Muscular Bio-Stimulator -  Particularly suitable for cellulitis treatment; 3V battery supply, portable set __ Contact Flavio Dellepiane, fladello @ tin.it

Muscular Bio-Stimulator 2nd Version -  improved version of the popular circuit.  increased output voltage, More complex output wave forms __ Contact Flavio Dellepiane, fladello @ tin.it

Muscular Stimulator -  Here is a circuit that stimulates nerves of that part of your body where electrodes are attached.  it is useful to relieve headache and muscular pain and revive frozen muscles that...__ Electronics Projects for You

mV Source for Thermocouple simulation -  I realized early that for prototyping and troubleshooting, I would require a millivolt source which can simulate a type K TC.  For now, this circuit is what I devised.  When the ECU is complete, I will do final calibration with a lab-grade TC simulator, and develop software interpolation of the non-linear curve.  But to simply create the Op-amp interface to amplify the signal, this little circuit seems to work quite well.  it is mounted on a 2" square PC board with a 9V battery.  I used a 10-turn 1K pot (expensive).  A normal pot will work fine.  Vary the 120K resistance to increase or decrease the mV signal range.  in this configuration, it will output a fairly stable 0 to 40 mV.  __ 

My First Experimental Ion Chamber -  An ion chamber is an extremely simple device that uses this principle to detect ionizing radiation.  The basic chamber is simply a conducting can, usually metal, with a wire electrode at the center, well insulated from the chamber walls.  The chamber is most commonly filled with ordinary dry air but other gasses like carbon dioxide or pressurized air can give greater sensitivity.  A DC voltage is applied between the outer can and the center electrode to create an electric field that sweeps the ions to the oppositely charged electrodes.  Typically, the outer can has most of the potential with respect to ground so that the circuitry is near ground potential.  The center wire is held near zero volts and the resulting current in the center wire is measured.   __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

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

 


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