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Tester or Measurement (Instrument) Circuits

Test Equipment:  #'s - A        B - D        E - G
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Last Updated: October 24, 2017 02:55 PM
Circuits Designed by Dave Johnson, P.E. :

Capacitance Type Liquid Level Monitor -  This circuit was originally designed to monitor the level of liquid natural gas in a tank but it can be used to also measure almost any liquid.  Two custom insulated metal tubes form a capacitor plate.  The capacitance between the two tubes increases as the level of the liquid rises . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Caps Provide Voltage Boost to Series Regulator -  This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range.  it can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply. . . Circuit by David A. Johnson P.E.-December, 1998

Characteristics of CMOS Logic Inverter Amplifiers -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers . . . Hobby Circuit designed by David A. Johnson P.E.-February, 2006

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Cable finder seeks out wall conduits -  05/11/00 EDN Design Ideas:  When you debug home electrical wiring, a tool that determines the location of cable conduits comes in handy, especially when problems arise.  Some tools, such as nylon or glass fiber guide as, contain small magnets and compasses that act as sensor elements __ Circuit Design by Luis Miguel Brugarolas and Manuel Ramón, Sire Sistemas y Redes Telematicas, Tres Cantos, Madrid, Spain

Cable Tester -  Have you ever wondered if a particular cable is delivering mains power supply to your device or not? Here is a solution that helps you test cable continuity without requiring any...__ Electronics Projects for You

Cable tester is fast & cheap -  09/24/98 EDN Design Ideas:  NOTE:  multiple circuits, scoll to this one.  The cable tester in Figure 1 uses a low-end 8-bit C.  The specific C to use depends on the number of conductors in the cable you want to test.  For the current application, two types of cables were under test, one with three conductors and another with seven.  So, the Motorola 68HC705P9 C was suitable.  The program first determines which type of cable is under test by checking the cable-switch position (Listing 1).  Then, the program checks each conductor line from A0/C0 to A7/C7 by putting a high-level voltage from output port A on one end of the wire and measuring the response on the other end, which is connected to the input port C.  if all of the checks show conductivity, the green "pass" LED turns on.   __ Circuit Design by Abel Raynus, Armatron International, Melrose, MA

Cable Tester Uses LEDs to Find Faults -  22-Oct-09 EDN Design Ideas:  Test as many as 16 wires with LEDs as continuity indicators __ Circuit Design by Pavel dek, Apri, Roznov pod Radhotem, Czech Republic

Cacophonator -  in the summer of 2006, Kevin Buckholdt and I designed and evaluated a number of circuits, with the goal of producing complex sonic effects with few components.  in naming our project, we derived the term "Cacophonator, " for cacophony plus oscillator.   __ Designed by Arthur Harrison

Calibrate scope jitter using a transmission-line loop -  09/20/01 EDN Design Ideas:  Digital-clock-period jitter is the variation in the period of a clock cycle compared with a nominal (average of many cycles] clock period.  To accurately measure period jitter using an oscilloscope, you must subtract the oscilloscope jitter from the measured jitter.  However, oscilloscopes rarely have a jitter specification, so you must determine the oscilloscope jitter __ Circuit Design by David Cuthbert, Micron Technology, Boise, ID

Calibrated trim tool tweaks multiturn pots -  01/07/99 EDN Design Ideas:  Many analog circuits contain multiturn trimming potentiometers whose settings you may need to change during maintenance or calibration.  Also, some instruments have panel-mounted potentiometers that may need periodic adjustments.  After disturbing a setting by more than one or two turns, it becomes difficult or impossible to restore the original setting.  The usual method   Page includes several designs.  Scroll to find this one __ Circuit Design by Sanjay Chendvankar, Tata Institute, Mumbai, India

Calibration technique uses sound -  09/01/98 EDN Design Ideas:  NOTE:     FILE
has many circuits, scroll down.  A number of Weidmuller Ltd's (www.weidmuller.com) products require output calibration for zero and span.  Normally, a technician calibrates a product by monitoring a digital readout and adjusting the zero and span potentiometers in turn.  Because the technician must concentrate so heavily on the readout, the technician often experiences eyestrain, and the screwdriver often slips from the potentiometer.  You can use an ADC card to implement the calibration function on a PC, and you can add an audio feature to simplify the calibration.  in some cases, the use of audio can replace the need for a digital readout. __ Circuit Design by Aubrey Kagan, Weidmuller Ltd, Markham, ON, Canada

Capacitance meter -  Every home constructor should own at least two pieces of test equipment: a digital (or analog) multimeter and a simple frequency counter.  Most digital multimeters can measure capacitance, but the capacitance range is rather limited __ Designed by Aren van Waarde

Capacitance meter -  Every home constructor should own at least two pieces of test equipment: a digital (or analog) multimeter and a simple frequency counter.  Most digital multimeters can measure capacitance, but the capacitance range is rather limited (in my case, from about 10pF to maximally 10 F).  it is not possible to check the value of large capacitors with such a meter, e.g.  bipolar electrolytics in a cross-over filter, or reservoir caps in a power supply.  in my attic, I have not only a digital multimeter but also a cheap frequency counter (0...10MHz).  So I decided to build a simple tool which would allow me to check the value of large capacitors, using the frequency counter. __ Designed by Aren van Waarde

Capacitance Meter -  This project is more complex than the others described earlier.  However, when finished, you will have an instrument capable of measuring all but the largest capacitors used in radio circuits.  Unlike variable resistors, most variable capacitors are not marked with their values.  As well, the markings of capacitors from salvaged equipment often rub off __ Contact IQ Technologies

Capacitance Meter -  Operates in conjunction with a voltmeter; 1pF to 22F in six Ranges - 9V Battery supply __ Contact Flavio Dellepiane, fladello @ tin.it

Capacitance meter (Colin Mitchell) -  This simple add-on capacitance meter has been specially designed to help you identify capacitors from 1p to 10u.   __ Designed by Collin Mitchell

Capacitance Meter (Elm-chan) -  This is a simple capacitance meter which can measure capacitance value easy.  There are some measurement methods for capacitance, at one time the capacitance was measured with a impedance bridge or a dip meter.   __ Designed by The Electronic Lives Manufacturing-presented Chan

Capacitance meter bins parts -  03/24/14 - EDN Design Ideas:  This simple, elegant circuit lets you quickly sort through capacitors - The heart of the circuit is the RS flip - flop using 4093 NAND gates along with transistors Q1 and Q2, which discharge the reference and test capacitors respectively.  The reference capacitor (CREF) and the test capacitor (CX) are charged from zero volts, followed by a reset pulse applied to the bases of Q1 and Q2 __ Circuit Design by Raju Baddi

Capacitance Meter to Build -  Please Scroll Down:  This project is more complex than the others described earlier. However, when finished, you will have an instrument capable of measuring all but the largest capacitors used in radio circuits.  __ Designed by Peter Parker VK3YE

Capacitance Type Liquid Level Monitor -  This circuit was originally designed to monitor the level of liquid natural gas in a tank but it can be used to also measure almost any liquid.  Two custom insulated metal tubes form a capacitor plate.  The capacitance between the two tubes increases as the level of the liquid rises . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Capacitor Evaluator -  Using this circuit and a known-value capacitor, you can find out the value of any capacitor.  The circuit can be divided into capacitor evaluator and display sections.  The capacitor evaluator circuit works...__ Electronics Projects for You

Capacitor Leakage Adaptor for DMMs -  Here's a cut-down version of the Digital Capacitor Leakage Meter we described in December 2009.  instead of using a PIC  microcontroller and an LCD panel to display the leakage current, this version connects to your DMM to provide the readout.  it provides the same range of seven different standard test voltages (from 10V to 100V) and can measure leakage currents down to 100 nanoamps! __ SiliconChip

Capacitor Leakage Meter with LCD Readout -  This instrument can perform a leakage current test on almost any type of capacitor in current use, including ceramic, mica, monolithic, metallised polyester or paper, polystyrene, solid tantalum and aluminium electrolytics.  There are seven different standard test voltages from 10V to 100V, so most capacitors can be checked at or close to their rated voltage.  Leakage currents can also be measured, from almost 10mA down to less than 100nA.__ SiliconChip

Capacitor self-diagnostICs -  EDN Design Ideas:  11/15/2016   The electrolytic capacitor is far from being the most reliable electronic component.  One of its failure modes a gradual loss of capacity can hardly be noticed until power supply malfunction occurs.  Thus, any chance to monitor the condition of the filter capacitors of an electronic device in situ would be a useful thing.  This simple Design ideas - Monitors capacitor voltages during power-down, and records out-of-spec conditions to available NVRAM/EEPROM. __ Circuit Design by Peter Demchenko

Caps Provide Voltage Boost to Series Regulator -  This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range.  it can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply. . . Circuit by David A. Johnson P.E.-January, 1998

Car Battery Failure Detector -  A car battery deteriorates in use and its life seldom exceeds four years.  When new, its voltage may drop to only 2V while cranking the engine.  As the battery ages, its internal impedance increases and so the voltage drop while cranking also increases, until ultimately the drop is high enough to prevent the engine from__ 

Car Battery Monitor -  Don't get caught with a flat battery.__ SiliconChip

Car Battery Tester -  Scroll to this one.  Checking the status of your car battery (accumulator) should be easier with this circuit which measures the internal resistance of the battery __ Designed by di Domenico Di Mario

Car battery Tester -  Checking the status of your car battery (accumulator) should be easier with this circuit which measures the internal resistance of the battery.  Pulses generated by the 555 are used to drive a dummy load and the AC voltage which develops across the battery gives an indication of its internal resistance: the lower the voltage the healthier the battery.  The AC voltage is read out by means of a digital meter __ Designed by D. Dimarios is listed as contact person

Car Coil Output Voltage Tester -  These circuits are designed to Test the High Voltage Output of a Car ignition Coil.   __ Designed by G.L. Chemelec

Car Loop Detector -  A Simple Circuit, but not as Stable as I would like.  Bury the coil in your driveway and it will detect any vehicle there.   __ Designed by G.L. Chemelec

Car speed Detection Device -  Door lock is easy to forget.  Even if it does not lock there is seldom case the door opens during travelling.  Even with, when you are getting a child, the child plays and may open the door.   __ Designed by Seiichi Inoue

Catalytic Comustible Gas Sensor -  Combustible gas mixtures will not burn until they reach an ignition temperature.  However, in the presence of certain chemical media, the gas will start to burn or ignite at lower temperatures.  This phenomenon is known as a catalytic combustion.  Most metal oxides and their compounds have these catalytic properties__ International Sensor Technology

CC2541 Keyfob Reference Design -  The Bluetooth Smart Keyfob is a small-form factor, coin-cell powered mobile accessory with buttons, buzzer, LEDs and accelerometer, demonstrating the use of several of the BLE GATT service profiles, like the proximity and battery service profiles.__ Texas Instruments

CCO Metal Detector -  To the best of the author's knowledge, the metal detector shown here represents another new genre.  it is presented here merely as an experimental idea, and operates in conjunction with a Medium Wave radio.  Elektor Magazine.   __ Designed by Published in issue 345, July 2005

CCO Metal Detector -  A Coil Coupled Operation Metal Detector made from readily obtainable components and using an ordinary medium receiver as a detector.   __ Designed by Rev. Thomas Scarborough

CD strobe scope -  This is a strobe scope.  The disc is rotating but it looks still.   __ Designed by The Electronic Lives Manufacturing-presented Chan

CD4 069 LED Bar Graph -  This simple bar graph display uses an ordinary CD4069UB hex inverter.  Despite the limited number of LEDs, this display may be used for fine peaking and viewing small changes in amplitude, because the brightness of the most significant LED varies with amplitude.  As the voltage increases from zero, the first LED grows in brightness.  Just when that LED is fully lit, the next LED begins to glow slightly.  Each LED represents about 1 volt of change, when the circuit is operating from 9 volts __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

CDV700 Geiger Counter Probe Rebuilding -  This article describes the process of rebuilding a geiger counter probe from the Victoreen CDV700 geiger counter.  The process of converting the hard-wired probe to a probe with a pluggable BNC connector is also described.  The probe from the model CDV700-6B is similar, but not identical, the socket is easier to access on that model.   __ Designed by Forrest Cook

Cell-Cycler Sorting Sires Superior Batteries -  06/23/94 EDN Design Ideas:  To assemble superior NIC d batteries, you need to form and match  individual cells making up a battery.  First, formation takes place in a NIC d cell only after numerous charge-discharge cycles.  Second, you must collect voltage data during se cycles to match up cells having uniform characteristics __ Circuit Design by Charles H Small, Senior Technical Editor

Cellular Phone calling Detector -  Flashes a LED when detecting an incoming call; Powered by one 1.5V cell __ Contact Flavio Dellepiane, fladello @ tin.it

Celsius-to-digital thermometer works with remote sensor -  04/15/04  EDN Design Ideas:  You can use a single-supply system to precisely measure the temperature at a remote location with less than 1C error over a 0 to 100C range (Figure 1).  The circuit includes T1, a low-cost AD590 temperature sensor; IC 1, an AD8541 r __ Circuit Design by Elana Lian and Chau Tran, Analog Devices, Wilmington, MA

characteristics of CMOS Logic Inverter Amplifiers -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers . . . Hobby Circuit designed by David A. Johnson P.E.-February, 2002

Characterizing noise in high-performance voltage-reference ICs -  09/03/09  EDN Technical Article: Measuring the noise performance of a modern voltage reference requires special measurement techniques.   __ Circuit Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke.  He was 63.

Charge Integrator-175.0 -  Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc

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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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