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Tester or Measurement (Instrument) Circuits

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Last Updated: November 30, 2017 02:27 PM
Circuits Designed by Dave Johnson, P.E. :
Solar-Powered Pump Motor Controller -  A Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by Dave Johnson P.E.-October, 2010

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:

Solar tracker -  This kit monitors the position of the sun using two Light Dependant Resistors (LDR's) , and makes the decision to move the solar panel to correctly orientate to the sun.   The output configuration is called a H bridge which will drive a small electric gearbox up to 500mA at the input voltage (6 ..15V) , both forward and reverse.__ CdS Electronic

Solar-Powered Pump Motor Controller -  A Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by Dave Johnson P.E.-October, 2010

Soldering iron driver bridge controls temperature -  09/06/13   EDN Design Ideas:  With a power supply and a replacement soldering handle you can implement this temperature-controlled soldering iron driver.  One way you can control the temperature of a soldering iron is with a microcontroller, using temperature feedback from the thermistor in the handle near the iron's tip.  This Design idea presents a soldering iron driver that does this using only analog components.   __ Circuit Design by Kiril Karagiozov

Solenoid Current Monitor for Ground Tied Solenoid -  The common mode inputs to the LT1999 switch between Vs and one diode drop below ground.  The LT1999 is a high speed precision current sense amplifier, designed to monitor bidirectional currents over a wide common mode range.  The LT1999 is offered in three gain options: 10V/V, 20V/V, and 50V/V.  The LT1999 senses current via__ Linear Technology/Analog Devices App Note, Nov 16th 2010

Solenoid is Pulled High to 24V, Freewheels Low to a Schottky BeLow Ground -  The large input common mode range of the LT6105 makes it suitable for monitoring currents in quarter, half and full bridge inductive load driving applications.  This circuit shows an example of a quarter bridge.  The MOSFET pulls down on the bottom of the solenoid to increase solenoid current.  it lets go to decrease current, and __ Linear Technology/Analog Devices App Note, Mar 31, 2010

Solenoid trip works at battery's end of life -  8-Jul-04 EDN Design Ideas:  This design idea involves a low-power motion-detector circuit that operates from battery power for extended times.  Part of the design includes a solenoid-operated trip mechanism that triggers whenever it detects motion.  The drive circuit for the solenoid in the original design worked fine as long as the battery was fresh but failed as the battery got into the middle of its life, even though suf __ Circuit Design by Brad Peeters, Theta Engineering, Costa Mesa, CA

Solid State Signal Lamp -  This solidstate signal lamp is a good alternative to revolving mechanical signaling lamps used in ambulances.  it uses ultra-bright blue LEDs for signaling.  However, you can replace blue LEDs with bright...__ Electronics Projects for You

Solid-State Relay Saves Battery's Life -  09/01/94 EDN Design Ideas:  The circuit in Fig 1 uses a low-resistance p-channel FET, Q4, to disconnect a load from the battery when the battery's voltage drops below a certain value.  After you disconnect the circuit, it remains off until you remove and replace the battery __ Circuit Design by Tom Gay, Siemens, Regensburg, Germany

Solid-state relays simplify Monitoring electric car battery-voltage -  02/19/04  EDN Design Ideas:  Figure 1 shows the propulsion system of an electric vehicle.  it includes an electric motor, drive electronics, a mechanical transmission, vehicle control/power management, a charging system, and a battery.  The long-term performance __ Circuit Design by Robert Krause, Fairchild Semiconductor, San Jose, CA

Some Simple Circuit test equipment to build -  amateur radio construction projects.   __ Designed by Peter Parker

Some test equipment to build -  amateur radio construction projects.   __ Designed by Peter Parker

Sonar Water-Level Meter -  Three-fourths of the earth is water, out of which 97 per cent is saline (in oceans, seas and groundwater).  The remaining 2.5 per cent to 2.75 per cent is fresh water, ...__ Electronics Projects for You

Sound Card Interface for PC Test Instruments -  You can have a virtual electronics lab in your PC.  Just attatch this simple interface to your sound card.__ SiliconChip

Sound Level Meter -  One chip replacement for the standard analog meters, based on LM3915 audio level IC .   __ Designed by Aaron Cake

Sound Level Meter -  This sound level meter circuit can be used to control the intensity of a sound recording or in a disco.  it has 5 measurement domains between 70 and 120 dB; reading accuracy is 0.5 dB.  Microphone M1 is used to receive the acoustic signal and is coupled to C1, C2, R1 and R2.  This components, together with the microphone’s __ Designed by Popescu Marian

Sound Pressure Level Meter -  This SPL meter will allow for a broad range of Sound intensitity Tests.   The 4 Transistors near the middle of the schematic, Basically make an integrated Circuit, Op-Amp.   I Specifically built it this way, as it really isn't much bigger an IC and these are very common transistors. __ Designed by G.L. Chemelec

Soundmeter -  A simple soundmeter using the PIC  16F628 or 16F84 __ Designed by Jose Pino

Spark Detector Uses Proximity -  27-Nov-08 EDN Design Ideas:  Use a Hall-effect sensor to measure engine rpm with a voltmeter __ Circuit Design by Robert Most, Ferris State University, Big Rapids, MI

SPDIF Monitor -  The SPDiF monitor is one of the many applications possible with the digital audio interface receiver Type CS8412 from Crystal.  Other applications described in earlier issues of this magazine dealt with the decoding of the S/PDiF (Sony/Philips Digital interface Format) into data, bit clock and L/R clock in a digital voltmeter __ Designed by Popescu Marian

Specialized test judges DMT-amplifier performance -  11/20/97 EDN Design Ideas:  Raditional analog test techniques and specifications, which are based on sine-wave testing, don't reflect the true performance of devices that process the discrete-multitone waveform.  A unique specification--the multitone power ratio--is a better performance indicator for this application.    __ Circuit Design by Richard Roberts, Harris Semiconductor

Spectrum analyser provides faster measurement -  04/01/99 EDN Design Ideas:  NOTE:  File contains many designs.   Scroll to this one.   Hewlett-Packard’s ESA-E spectrum analysers (Picture] let you perform measurements in less time and access a range of software routines to aid common measurement tasks.  Five models cover 1.5 to 26.5 GHz; they have 5-msec full-span RF sweep times and can repeat measurements as fast as 28 times/sec.  Span accuracy from the synthesized source is ±1%, and amplitude accuracy is ±1 dB.  Ultimate   Page includes several designs. __ Circuit Design by Graham Prophet

Spectrum Analyzer & Equalizer Designs -  for audio frequencies, article first appeared in the February1982 issue of Recording-engineer/producer magazine __ Designed by Ethan Winer

Spectrum Analyzer Measurements & Noise -  Application Note__ Aligent

Spectrum analyzer Mk 1 -  A spectrum analyser is a very useful piece of test equipment to have on your workbench, yet the price tag of commercially avialable analysers places them way outside most hobbyist budgets, even when 2nd hand.  All is not lost - here's a spectrum analyser design you can build yourself that won't break the bank.  The pages linked above describe the construction in detail.  Most photograph insets can be clicked to view a larger high resolution image. __ Designed by Hans Summers

Spectrum analyzer Mk 2 -  After enjoying the Simple man's Spectrum Analyser so much, here's some real insanity.  The Mk2 spectrum analyser is an attempt to resolve some of the shortcomings of the original simple analyser, improve performance, and add hosts of features.  The display uses an ex-TV tube, with digital storage.  Purely for the fun of it, the digital circuits are built using discrete logic rather than a microprocessor. __ Designed by Hans Summers

Spectrum Analyzer on the Oscilloscope -  Schematic only __ Designed by va3iul

Spectrum Analyzer using TV-Tuner-W6WTU -  Schematic only __ Designed by va3iul

Speed Alarm for Cars; Pt 1 -  is your license looking a bit a bit dodgey? This compact speed alarm will help you stick to the speed limits.__ SiliconChip

Speed Checker for Highways -  While driving on highways, motorists should not exceed the maximum speed limit permitted for their vehicle.  However, accidents keep occurring due to speed violations since the drivers tend to ignore their...__ Electronics Projects for You

Speed Control Of DC Motor using Pulse-Width Modulation -  Pulse-width modulation (PWM) or duty-cycle variation methods are commonly used in speed control of DC motors.  The duty cycle is defined as the percentage of digital ‘high’ to digital ‘low’ plus...__ Electronics Projects for You

Speed Controller for DC Motor -  Here is a simple circuit to control the speed of a DC motor.  it can be configured to control the sweep rate of automobiles’ windscreen wiper.  The circuit comprises a timer NE555...__ Electronics Projects for You

Speed Controller for Film Projectors -  Do you have old family movies on film? Have you watched them lately? You may be shocked by how much they have deteriorated over the years.  They need to be transferred to DVD before the film deteriorates to the point where it is unwatchable.  Video conversion is not as straightforward as you might think but this simple project enables you to do it.__ SiliconChip

Speed Controller for Small Cooling Fans -  Small cooling fans are used in some equipment for cooling semiconductor devices.  The circuit given here is of a simple automatic speed controller for a 12V, 0.6W (or 1.2W) cooling fan...__ Electronics Projects for You

Speed IM testing -  Application Note__ MiniCircuits.com

Speed Limit Alarm -  Wireless portable unit; Adaptable with most internal combustion engine vehicles __ Contact Flavio Dellepiane, fladello @ tin.it

Speedometer For Model Cars -  Avid model car fans are naturally enough always interested in the technology and performance of their cars.  They would like to know as exactly as possible how fast their model cars actually go, for example so that they can select the final gear ratio for the best performance.  Other factors can also be of interest, __ 

Spice 3 Models Pressure Sensors -  01/01/98  EDN Design Ideas:  Commercially available versions of Spice 3, such as isSpice4 (intusoft, San Pedro, CA) , can simulate mixed-domain systems containing electrical, mechanical, physical, and mathematical elements using behavioral models.  You can use these features to simulate a variety of components.  For example, the generic subcircuit in Figure 1 and the corresponding listing model the simple linear behavior of a pressure transducer.   __ Circuit Design by Debra Horvitz, Galahad Systems, Laguna Hills, CA

Spice Accepts & Displays Y Parameter -  08/04/94 EDN Design Ideas:  Admittance or Y parameters have been the favorite of many high-frequency analog engineers for many years.  Y parameters provide insights into circuit behavior not as apparent as with the more popular S parameters.  Although S parameters suit single-stage designs, modeling techniques that are impedance independent--namely Y parameters--suit IC designs best. __ Circuit Design by Michael A Wyatt, Honeywell SSAVD, Clearwater, FL

Split or Single Supply Operation, Bidirectional Output into A/D -  in this circuit, split supply operation is used on both the LT1787 and LT1404 to provide a symmetric bidirectional measurement.  in the single-supply case, where the LT1787 pin 6 is driven by VREF, the bidirectional measurement range is slightly asymmetric due to VREF being somewhat greater than mid-span of the ADC input range.  __ Linear Technology/Analog Devices App Note, Mar 31, 2010

Sprague TO-5 Tel-Ohmike capacitor analyzer manual w/schematic -  Circuit Only __ Designed by Sprague

Sprague TO-6A Tel-Ohmike capacitor analyzer manual w/schematic -  Circuit Only __ Designed by Sprague

Square Root Function Improves Thermostat -  09/30/99 EDN Design Ideas:  Perhaps the most elementary rule of control-loop design theory is that feedback-loop performance is fundamentally linked to the careful choice—and stability—of loop gain.  insufficient loop gain leads to poor setpoint accuracy.  Too much gain can induce feedback instabilities,  __ Circuit Design by W Stephen Woodward, University of North Carolina, Chapel Hill, NC

Standalone Digital Voltmeter Uses a Multichannel ADC -  11/15/12  EDN Design Ideas:  Monitor several different voltages with one instrument.  This Design idea was realized for voltage/current measurement on a four-channel analog voltage source but has wide use in many other applications.  The design is based on the Atmel ATmega8-16AC microcontroller and the MAX1230 12-bit ADC (references 1 and 2).  Although the microcontroller has an internal 10-bit ADC, it’s more efficient to use an external multichannel ADC than to multiplex more analog channels to the ATmega8-16AC differential ADC inputs __ Circuit Design by Branislav Korenko

Standalone LED tester -  Description and schematic for a constant-current LED tester.  it safely lights up standard through-hole and surface mount LEDs, while providing easy access to current and voltage measurements.   __ Contact David Cook

Standardized Core Makes Building & Supporting a Functional Test System Easier & Less Costly -  Application Note__ Aligent

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