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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. :

Slotted Opto-Sensor used in Honeybee Counter -  I designed a circuit similar to this one a long time ago to help a beekeeper count the number of bees going into or out of a hive.  The low power circuit uses a slotted opto-sensor to detect the passing bees.  The circuit advances an electronic counting . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000

Small Battery Capacity Tester -  I have a client who uses a lot of batteries.  His sells a device which is powered by a 3v lithium coin cell and he sells thousands of them.  it seems that many of the batteries he has been importing from China have a milliamp-hour capacity which is much . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2008

Snow Depth Alarm -  The design of this system alerts a snowplow driver when the snow depth has exceeded four inches.  A visible red LED packaged in a 10mm package is pulsed at a rate of about 50Hz with 10uS pulses.  Twenty four inches away a phototransistor detects the light from the LED.  The LED and the phototransistor are housed in a section of ½ inch PVC pipe, forming a waterproof seal. . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Solar Cell Test Fixture -  if you are considering building your own solar panel, you might try building the solar cell tester shown below.  When constructing a solar panel it is important to make sure that all the solar cells used in the panel be closely matched for their short circuit . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2007

Solar Insolation Monitor -  Owners of photovoltaic solar panels often like to monitor how bright the sunshine is.  They can use this information to gage how well their solar panels are doing.  On a typical clear day, the sun energy at sea level is about 1000 watts per square meter . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2012

Solar Path Light Improvement -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that. . . Circuit by David A. Johnson P.E.-March, 2011

Solar PV Cell Test Fixture -  This is an illustration of a test fixture, which can be used to test individual solar cells for short circuit current.  Using a PIN photo diode and a control circuit, the solar cells can be tested under constant light level conditions. . . Circuit by David A. Johnson P.E.-October, 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:

Single Chip Metal Detecor -  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

Single Hex-Inverter IC Makes Four Test Gadgets -  07/30/12  EDN Design Ideas:  This can be a fun project for students and seasoned engineers alike.   __ Circuit Design by Raju Baddi

Single IC forms inexpensive inductance tester -  08/02/07  EDN Design Ideas:  A simple Pierce oscillator measures the inductance of a device under test __ Circuit Design by Luca Bruno, ITIS Hensemberger Monza, Lissone, Italy

Single IC Forms Precision Triangular-Wave Generator -  04/08/10 EDN Design Ideas:  Generate a triangular wave for testing other circuits.   __ Circuit Design by Akshay Bhat, Maxim Integrated Products Inc, Sunnyvale, CA

Single Phase Energy Metering IC with On-Chip Fault Detection -  The ADE7751, available in SSOP packages, is pin compatible with the AD7751.  it has the same functionalities as the AD7751.  __ Analog Devices Product Notes

Single Phase Step-Down DC/DC Controller with Digital Power System Management & Input Current Sense -  The digital power supply market has achieved rapid progress in the recent years.  Easy configuration, accurate telemetry, convenient fault analysis and reliability are the trends for the modern digital power supply, which are all provided by Linear’s new digital power controller, the LTC3883.  The LTC3883 is a single phase __ Linear Technology/Analog Devices App Note, Yi Sun-Applications Engineer Oct 4th 2012

Single Supply Current Source for Platinum RTD -  The LT1800's Precision and low bias input stage is used to good advantage in Fig.5 Single Supply Current Source for Platinum RTD circuit.  R4 and C1 stabilize the circuit making it insensitive to cable characteristics.  Output is 1.00V at 0ºC and its gain factor is 3.85mV/ºC.  __ Linear Technology/Analog Devices App Note, Jul 2, 2012

Single Supply Shock/Vibration Sensor Amplifier -  The LTC6087/LTC6088 are dual/quad, low noise, low offset, rail-to-rail input/output, unity-gain stable CMOS operational amplifiers that feature 1pA of input bias current.  A 14MHz gain bandwidth and 7.2V/μs slew rate, combined with low noise (10nV/√Hz) and a low 0.75mV offset, make the LTC6087/LTC6088 useful in a variety __ Linear Technology/Analog Devices App Note, Jul 25th 2012

Single Supply Type K Thermocouple Signal Conditioning Amplifier with Cold Junction Compensation -  The LTC2050 is a zero-drift precision chopper stabilized operational amplifier available in the 5- or 6-lead SOT-23 and SO-8 packages.  it minimizes board area while providing uncompromising DC performance, including 3mV (max) DC offset and 30nV/°C (max) DC offset drift.  it operates from a 2.7V supply while still supporting __ Linear Technology/Analog Devices App Note, Apr 9th 2010

Single Supply, Micropower Toxic Gas Detector using an Electrochemical Sensor  -  The CN-0234 evaluation software communicates with the SDP board to capture data from the EVAL-CN0234-SDPZ circuit evaluation board.  , Equipment Needed The following equipment is needed:, Bullet text, Getting Started Load the evaluation software by placing the CN0234 Evaluation Software CD into the CD drive of the PC.  __ Analog Devices from the Lab

Single switch controls digital potentiometer -  02/27/02 EDN Design Ideas:  The control of electronic potentiometers in most today's applications comes from controller-generated signals.  However, a significant number of applications exist that require adjustments using manual, front-panel controls.  The circuit in Figure 1 uses one IC , one switch, and 10 discrete components __ Circuit Design by Chuck Wojslaw and Gary M Craig, Catalyst Semiconductor, Sunnyvale, CA

Single-Supply Linearizes RTD -  12/21/95 EDN Design Ideas:  Accurate temperature measurement in single-supply, low-power applications presents a difficult signal-conditioning problem.  in many applications, the temperature sensor may be located a fair distance from the signal-conditioning circuitry, and, as a result, the measurements may __ Circuit Design by Adolfo Garcia, Analog Devices Inc Santa Clara, CA

Single-Supply Measures –48V High-Side Current -  02/21/08 EDN Design Ideas:  This circuit measures –48V high-side current using a single positive supply.    __ Circuit Design by Wenshuai Liao, Analog Devices, Beijing, China; Stephen Lee, Analog Devices, Wilmington, MA; and Yanhui Zhao, Beihang University, Beijing, China

Sleep easy with this Desk fan speed reducer -  EDN Design Ideas:  12/08/2014     This innovative AC motor control skips cycles.   Most desk fans I have come across have three speeds: Full Speed, Almost Full Speed, and Off – useless if you want just a gentle air movement, and far too noisy if you are trying to get to sleep (in your bedroom of course, not at your work desk!).  The squirrel cage induction motors they use have switches to two or more windings – and possibly a capacitor – to reduce the drive current.  But unless the drive frequency is also reduced, the torque and speed stability are poor, so minimal speed reduction is usually available on these fans.  Using a TRIAC to provide phase control of the voltage works poorly for the same reason, with the speed very sensitive to the TRIAC firing phase angle and fan load, and has a tendency to stall. __ Circuit Design by Mike Whybray

Sleeping aid -  Many people experienced sleeping well in natural surroundings, into a tent or a wooden hut.  This fact is due not only to the healthy atmosphere but also from our unconscious ability to perceive natural Earth's magnetic-fields.  The circuit generates this type of Geo-magnetic-fields and lets us perceive them: in this manner our brain is surrounded by an ideal environment for a sound sleep. (N.B.  Basic ideas for this circuit are coming from German papers).__ Learning Electronics

Sleeping Aid -  Based on electromagnetic-field radiation; Place it under the pillow - Built-in timer __ Contact Flavio Dellepiane, fladello @ tin.it

Slew Rate Verification for Wideband Amplifiers: The Taming of the Slew -  Linear Technology AN94 __ Designed by Jim Williams - May 1st, 2003

Slotted Opto-Sensor used in Honeybee Counter -  I designed a circuit similar to this one a long time ago to help a beekeeper count the number of bees going into or out of a hive.  The low power circuit uses a slotted opto-sensor to detect the passing bees.  The circuit advances an electronic counting . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000

Small Battery Capacity Tester -  I have a client who uses a lot of batteries.  His sells a device which is powered by a 3v lithium coin cell and he sells thousands of them.  it seems that many of the batteries he has been importing from China have a milliamp-hour capacity which is much . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2008

Small Detector Coils with Ferrite Cores for my PI Detectors -  Over the years I have wound and experimented with Hundreds of coils.  Many Varied Sizes and Shape.  Considerably interesting are the Small coils wound on Ferrite cores.   __ Designed by G.L. Chemelec

Small, portable altimeter operates from a single cell -  06/21/01 EDN Design Ideas:  Some sports enthusiasts want to know altitude changes from an initial elevation.  A small, lightweight, portable altimeter is easy to design using modern micromachined pressure transducers.  inverting barometric pressure and compensating for nonlinearities in air-pressure changesseveral designs included, scroll to find this one __ Circuit Design by Todd Owen, Linear Technology Corp, Milpitas, CA

Smart Continuity Tester -  Occasionally you need a continuity test between two points in an electronic circuit.  Unfortunately, most continuity testers are prone to "lie".  They don't do that deliberately, but if they see a small resistance, they still tell you that you have continuity.  They just don't know any better __ Designed by Tony van Roon  VA3AVR

Smart Hearing Aid -  Normally, hearing aid circuits consume battery power continuously once they are switched on.  The circuit given here saves battery power by switching on the sound amplifier section only when sound is...__ Electronics Projects for You

Smart Vibration Sensor -  in this vibration sensor alarm circuit, initially, when power switch S1 is flipped to 'on' position, power indicator LED1 lights up immediately.  IC LM555 (IC 1) , wired as a simple latch circuit...__ Electronics Projects for You

SmartCard PC Emulator -  This smartcard adapter follow exactly the specification iSO 7816.  Also, the protocol is the "asynchronous half duplex T=0 protocol" with "active low reset" and "inverse convention" as defined in this standard.   __ Designed by Markus Kuhn

Smoke Detector -  Smoke Detectors are designed for 3 basic types of system implementations; Standalone, Wireless Connectivity, and Fixed/Wired Connectivity, the first two being battery powered implementations.  Smoke Detectors have 3 main functional blocks; The Sensor and Signal Chain, Processor, and the Communication interface.  Where the processor and communications interface typically are not needed in your very basic standalone detectors__ 

Smoke, Alcohol & LPG-Detection Alarm -  Presented here is a circuit for raising an alarm on detecting smoke or LPG cooking gas leakage, or even alcohol vapours in breath.  This is achieved by using a basic unit...__ Electronics Projects for You

Snore Alarm -  The idea behind this snore alarm, is just to rouse the snorer, not the entire household.  To wake the sleeper, vibration is used, not an audible alert.  The vibration is provided by a small motor housed in a small 35mm film case, which can be placed under the sleepers mattress or pillow.  This circuit has a level control and peak display indicator, a variable trigger __ Designed by Andy Collison

Snore Alarm Electronic Device -  Here I describe a little electronic device that detects snoring.  The principle though very simple is efficient and well protected against false triggerings.  Upon detection, it generates a noisy and painfull alarm.  Just what's necessary to wake up everybody except the snorer.   __ Designed by chabin laurent

Snow Depth Alarm -  The design of this system alerts a snowplow driver when the snow depth has exceeded four inches.  A visible red LED packaged in a 10mm package is pulsed at a rate of about 50Hz with 10uS pulses.  Twenty four inches away a phototransistor detects the light from the LED.  The LED and the phototransistor are housed in a section of ½ inch PVC pipe, forming a waterproof seal. . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Soft Power On Tester for Amplifiers -  I run into this a lot, so I decided to draw it up.  Sometimes you are trying to fix a problem with an amp or other equipment that you're concerned might have a power fault.  The worst thing that can happen is that when you turn it on, it immediately pops a fuse - or worse yet a valuable part you've just installed!  if you don't have a variac with a current meter so that you can make power on gradual,  __ Designed by R.G. Keen

Soft Start for Power Amps -  Although the soft start circuit can be added to any sized transformer, the winding resistance of 300VA and smaller transformers is generally sufficient to prevent a massive surge current.  Use of a soft start circuit is definitely recommended for 500VA and larger transformers __ Designed by Rod Elliott  ESP

Soft-start controller is gentle on loads -  11/22/01 EDN Design Ideas:  The control circuit in Figure 1 senses a given load and automatically soft-starts the load by synchronously adjusting the power to that load.  You can also manually adjust the power delivered to the load by controlling the phase angle of the line voltage across the load.  The phase-angle adjustment for every ac half cycle covers 0 to 180° __ Circuit Design by Douglas Sudjian, Resonext Communications Inc, San Jose, CA

Software Implements Digital Potentiometer -  06/08/95 EDN Design Ideas:  in some applications (for example, dynamic biasing of laser diodes) , the use of digital potentiometers, or trimDACs, has limitations because of resolution, accuracy, or interface difficulties.  Using the simple (but maybe not so obv __ Circuit Design by Gray Creager,  Xicor Inc, Milpitas, CA

Software-Calibrated, 50 MHz to 9 GHz, RF Power Measurement System  -  For example if the CODE from the ADC is between CODE_1 and CODE_2, then the SLOPE1 and iNTERCEPT1 should be used.  For example, if the CODE from the ADC is greater than CODE_1 or less than CODE_4, it indicates that the measured power is outside of the calibration range.  , Figure 3 also shows the transfer function variation of the circuit vs.  the above straight line equations.  The error is expressed in dB using the equation:        Error (dB) = Calculated RF Power − True input Power        = (CODE/SLOPE) + iNTERCEPT – PIN_TRUE Figure 3 also includes plots of error vs.  temperature__ Analog Devices from the Lab

Soil Moisture Tester -  Plants seem to have something in common with pets.  They are usually acquired or given with the best intentions, but not everybody seems to be able to look after them properly.  Of course we do not expect everybody to have green fingers, but when plants are not watered enough they simply die.  in any case, too much neglect usually has fatal consequences.  Cactuses seem to survive such a careless treatment the longest and we have to admit that these are the only plants that manage to survive at our offices.   __ Designed by Popescu Marian

Solar Cell Test Fixture -  if you are considering building your own solar panel, you might try building the solar cell tester shown below.  When constructing a solar panel it is important to make sure that all the solar cells used in the panel be closely matched for their short circuit . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2007

Solar Current Meter -  This circuit is used to measure the current from a solar panel.  it has very low power loss for currents in the 0-10A range.  it also works as a general purpose DC current meter.  The circuit can be used on either the positive or negative side of a DC circuit __ Designed by G. Forrest Cook

Solar Insolation Monitor -  Owners of photovoltaic solar panels often like to monitor how bright the sunshine is.  They can use this information to gage how well their solar panels are doing.  On a typical clear day, the sun energy at sea level is about 1000 watts per square meter . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2012

Solar Panel Current Meter -  This circuit is used to measure the current from a solar panel.  it has very low power loss for currents in the 0-10A range.  it also works as a general purpose DC current meter.  The circuit can be used on either the positive or negative side of a DC circuit __ Designed by G. Forrest Cook

Solar Path Light Improvement -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that. . . Circuit by David A. Johnson P.E.-March, 2011

Solar Powered Wireless Weather Station -  it's based on PIC AXE processor and "wirelessly" transmits temperature and humidity data to a receiver up to 200 metres away.__ SiliconChip

Solar PV Cell Test Fixture -  This is an illustration of a test fixture, which can be used to test individual solar cells for short circuit current.  Using a PIN photo diode and a control circuit, the solar cells can be tested under constant light level conditions. . . Circuit by David A. Johnson P.E.-October, 2006

Solar Radiation Meter -  Schematic + info + pictures __ Designed by Lennie Zink

Solar Shed Lighting Testing -  Analysis of a typical solar shed LED lighting circuit.   __ Designed by REUK-Renewable Energy UK website

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


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

 


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