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Tester or Instrumentation Circuits, Page 7
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Last Updated on:
Monday, October 03, 2011 06:08 PM

Circuits Designed by Dave Johnson, P.E. :
  • INDUCTOR SELF-RESONANCE TESTER
    If you want to know what the self-resonance frequency is of an inductor, this circuit will help. It adds only a few picofarads of parallel capacitance to the inductor under test. With the aid of an oscilloscope and a signal generator this circuit will allow you to measure resonant frequencies from kilohertz to over 10 megahertz.
  • ISOLATED AC CURRENT MONITOR
    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 amps of AC current and provides at least 500vac of isolation.  With the components shown, the output AC voltage is scaled so 1 amp of current produces 100mv of AC voltage.

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

Handling Instructions & Protection Against Electrostatic Discharges -  Application Note Microsemi-formerly Advanced Power Technology APT0502  ( app note added 05/07)
Hardware histogram speeds ADC test -  13-Nov-03 Issue of EDN  Accumulating enough samples to effectively and accurately measure linearity errors in pipeline converters at production test and minimizing test time are difficult enough. Add to that multiple sites, multiple channels, and the expense of multiple custom-instrument resources during periods of low capital expenditure, and engineers must think creatively to increase throughput without sacrificing.... [Design Idea by Tony Zizzo Jr, Texas Instruments, Tucson, AZ]
Heath EU-14A "Special Experimental Parts" specs & schematic -  (added 07/07/07)
Heath EUP-26 VOM specs & schematic -  (added 07/07/07)
Heath EUW-16 Voltage Reference Source specs & schematic -  (added 07/07/07)
Heath EUW-17 Transistor Power Supply specs & schematic -  (added 07/07/07)
Heath EUW-19A Operational Amplifier System specs & schematic -  (added 07/07/07)
Heath EUW-20A Servo-Recorder specs & schematic -  (added 07/07/07)
Heath EUW-24 VTVM specs & schematic -  (added 07/07/07)
Heath EUW-25 DC Oscilloscope specs & schematic -  (added 07/07/07)
Heath EUW-27 Sine-Square Wave Generator specs & schematic -  (added 07/07/07)
Heathkit AV-1 AC voltmeter schematic -  (added 07/07/07)
Heathkit G-5 Signal generator schematic -  (added 07/07/07)
Heathkit HD-1 harmonic distortion analyzer schematic -  (added 07/07/07)
Heathkit HD-1250 solid-state dipper schematic -  (added 07/07/07)
Heathkit HM-10A "Tunnel Dipper" schematic -  (added 07/07/07)
Heathkit IB-2 impedance bridge schematic -  (added 07/07/07)
Heathkit IM-18 VTVM schematic (similar to most other Heath VTVMs) -  (added 07/07/07)
Heathkit IP-17 0-400V regulated power supply schematic -  (added 07/07/07)
Heathkit IP-27 LV regulated power supply schematic -  (added 07/07/07)
Heathkit RC-1 Radiation Counter partial manual -  (added 07/07/07)
Hewlett-Packard 200CD AF oscillator schematic (early model with 6SH7/6AU5GT) -  (added 07/07/07)
Hewlett-Packard 206A AF oscillator schematic  -  (added 07/07/07)
Hewlett-Packard 3200B VHF oscillator operating & service manual -  (design added 08/03)
Hewlett-Packard 339A Distortion Analyzer manual -  (design added 07/07/07)
Hewlett-Packard 400 AF VTVM manual w/schematic -  (added 07/07/07)
Hewlett-Packard 410B RF VTVM schematic -  (added 07/07/07)
Hewlett-Packard 606A RF generator manual w/schematic -  (design added 07/07/07)
Hewlett-Packard 711A Power Supply manual -  (design added 07/07/07)
High & Low Voltage Cut Off With Time Delay -  The power line fluctuations and cut-offs cause damages to electrical appliances connected to the line. It is more serious in the case of domestic appliances like fridge and air conditioners. If a fridge is operated on low voltage, excessive current flows through the motor, which heats up, and get damaged.….(electronic schematic added 08/08) [Site is under construction right now]
High Impedance Voltmeter -  This circuit is designed to provide an inexpensive way to to create a High Impedance Voltmeter while making use of an inexpensive analog or digital multimeter. The circuit is specifically designed for testing phototransistors when they are used in the circuits shown at this site. It has a very high input impedance that will not "Load Down" the sensor that is being checked.... [from Rob Paisley's Model Train web site]
High Precision Rail-to-Rail Output Operational Amplifier -  National Semiconductor Application Note LMV2001 April 2004....[App Note]
High Resistance Voltmeter -  ....
High-impedance FET probe extends RF spectrum analyzer's usable range -  21-Jul-05 Issue of EDN  Op amp and careful design/construction build high-impedance RF probe.... [Design Idea by Steve Hageman, Windsor, CA; Edited by Brad Thompson and Fran Granville]
High-impedance voltmeter -  An ideal voltmeter has infinite input impedance, meaning that it draws zero current from the circuit under test.  This way, there will be no "impact" on the circuit as the voltage is being measured. The more current a voltmeter draws from the circuit under test, the more the measured voltage will "sag" under the loading effect of the meter, like a tire-pressure gauge....
High-side current monitor operates at High-Voltage -  22-Jul-04 Issue of EDN  The simplest technique for measuring current in an actuator or a motor is to monitor the ground current with a resistive element between the load and the ground. Because the device and its associated electronics share a ground potential, you need to amplify only the ground-current signal.  This approach, however, does not detect device short circuits to ground, which can overload the high-side d.... [Design Idea by Greg Sutterlin and Brian Whitaker, Maxim Integrated Products, Sunnyvale, CA]
High-Side Current Sensing: Considerations & Applications for High-Side Current Monitoring -  Zetec Semiconductors  Applications Notes  A guide for using the ZXCT range of products. Contained within the note are application ideas for extended supply ranges, a circuit for bi-directional current sensing and an over-current/short circuit protection circuit. Now updated and contained within AN39  (app note added 2/06)
High-side Current-sense causes little error -  0316/95 EDN-Design Ideas....Measuring dc would be simple if you could always reference your measurement signals to the positive rail. Unfortunately, most current-metering applications require a ground-referenced output. Typically, the signal that you want to measure consists of a small differential signal that rides on a large common-mode voltage.... EDN is migrating links. This link is not verified.  Search the "title" + "EDN" for new link.
High-side current-sensing switched-mode regulator provides constant-current LED drive -  14-Apr-05 Issue of EDN  Drive LEDs with constant-current source.... [Design Idea by Bradley Albing, Philips Medical Systems Inc, Cleveland, OH; Edited by Brad Thompson]
High-speed lightwave component analysis -  Aligent Application Note 1550-6  (added 4/08)
Home-Brew electronic altimeter -  A while back, I decided I wanted an altimeter to record how high my rockets were flying. I didn't want to buy one, since a) they aren't cheap (at least, not the ones which do everything I want them to do), and b) buying one is far too easy. I considered the CP Technologies kit, which is based on the Missile Works RRC2,....
HOTCHEK -  The HOTCHEK is a compact expanded scale voltmeter designed to check the receiver battery pack. Its very small size makes it great as onboard voltage monitor or it can be used as a "pocket meter," replacing those old fashioned bulky meters. A 0.3A load can be placed across the batteries with a push of a button allowing the true state of the pack to be tested ....
How to Use the MAXQ2000 as a Voltmeter -  Maxim App Note 4194  -- 3/24/2008 --  (app note add 5/08)
HP48SX IR DECODER -  (electronic design added 6/07)
HV430 105 Volt RMS Ring Generator -  Supertex Semiconductors  (app note added 2/06)
Hygrometer and hygrostat -  A simple handheld relative humidity meter, complete with settable control output. [Manfred Mornhinweg]
IC and DMM form direct-read-out temperature probe -  1-Sep-06 Issue of EDN  Simple circuit yields linear voltage-versus-temperature output.... [Design Idea by Alfredo H Saab and Bich Pham, Maxim Integrated Products Inc, Sunnyvale CA; Edited by Brad Thompson and Fran Granville]
IEC Compliant Active-Energy Meter Design using the MCP3905/6 -  Microchip Application Note Published 27-Jul-05....[App Note]
IEC Compliant Active-Energy Meter Design using the MCP3905/6Chinese -  Microchip Application Note Published 17-Oct-05....[App Note]
Improved current monitor delivers proportional-voltage output -  19-Jan-06 Issue of EDN  New, improved circuit delivers an accurate linear-voltage output proportional to current in primary winding.... [Design Idea by Susanne Nell, Breitenfurt, Austria; Edited by Brad Thompson and Fran Granville]
Improved Kelvin contacts boost current-sensing accuracy by an order of magnitude -  17-Feb-05 Issue of EDN  Many power-supply designs rely on accurately sensing the voltage across a current-sense element. Multiphase regulators use the sense voltage to force current sharing among phases, and single-phase regulators to control the current-limit setpoint. As internal complexity and clock speeds increase, processors impose narrower operating margins for power-supply voltages and currents, which in turn m.... [Design Idea by Craig Varga, National Semiconductor Corp, Phoenix, AZ]
Improved two-tone, third order testing -  Application Note MiniCircuits.com  (app note added 04/05/06)
In Circuit Transistor Checker -  It is able to check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier circuits….(added 04/05/06)
In-circuit electrolytic Tester -  This project comes in two versions: as an "add-on" for the 5x7 project (pages 1&2) and as a "stand-alone" project (pages3&4).  Read both sections before deciding on which version you will build….(circuit added 05/06)
Increasing Regulator Current -  An outboard pass transistor used to increase the current output of a voltage regulator IC….(added 01/2010) [Andy Collison - designer]
Indicator features expanded scale -  21-Feb-02 Issue of EDN  Test equipment for a production line should be user-friendly (read "idiot-proof"] and should offer minimal test time. In many cases, the test fixture must give an operator only one answer  pass or fail. Usually, two indicators assume this role  green for pass and red for fail. In most applications, a sensor transforms the tested parameter to a voltage; the test fixture must measure this v.... [Design Idea by Abel Raynus, Armatron International, Melrose, MA]
Inductance meter -  Determination of the resonance frequency of a parallel LC network is one of the most important measuring problems in the ham shack. Not unjustly the commonly used dip meter is nicknamed “sounding-rod of the radio amateur”.  A more elegant method for measuring the resonance frequency is …(circuit added 04/05/06)
Inductance meter  -  ....
Inductance meter adapter -  The following circuit enables me to measure inductance of the inductor labeled LX which is the inductance to be measured. The o/p of the circuit is a TTL square wave whose frequency relates….By Tosin Osanyintuyi (TAFRICA)  (circuit added 09/08)
Inductance meter for RF Inductors  -   needed a way to measure hand-wound RF inductors in my second lab, and since I would only be doing this occasionally, I didn't need anything fancy, and since once a friend finishes his AT90S1200-based design, I plan to make one myself, I figured I'd use this for less than a year, so I didn't t,....(schematic / circuit added 6/07)
Inductive meter adapter -  ….(design added 03/08)
Inductor Self-Resonance Tester -  If you want to know what the self-resonance frequency is of an inductor, this circuit will help. It adds only a few picofarads of parallel capacitance to the inductor under test. With the aid of an oscilloscope and a signal generator this circuit will allow you to measure resonant frequencies from kilohertz to over 10 megahertz. …. [Designed by David A. Johnson]
Infra Red Remote Control Tester) -  ….(design added 03/08)
Infrared Remote Control Tester -  This circuit is the result of my research. I have used a photodiode, SFH2030 as an infra red sensor. A MOSFET opamp, CA3140 is used in the differential mode to amplify the pulses of current from the photodiode. LED1 is an ordinary coloured led which will light when IR radiation is being received. The output of the opamp, pin 6 may be connected to a multimeter set to read DC volts. Infra red remote control strengths.... [Andy Collison designer]
Instrumentation amplifier extends DSO -  5-Jan-06 Issue of EDN  Elusive current waveforms required scope documentation.... [Design Idea by Bob Perrin, Sacramento, CA; Edited by Brad Thompson and Fran Granville]
Integrator enables simple ohmmeter with gigohm range -  24-May-07 Issue of EDN  With the aid of an external counter and control circuitry, this system can measure resistances in the tens of gigohms.... [Design Idea by Stefano Salvatori and Gennaro Conte, Università degli Studi di Roma Tre, Rome, Italy]
Integrator Forms Picoammeter -  07/17/97 EDN-Design Ideas.... EDN is migrating links. This link is not verified.  Search the "title" + "EDN" for new link.
Introduction to Time, Frequency & Modal Domains 5988-6765EN -  Aligent Application Note 1405-1  (added 4/08)
Invisible Broken Wire Detector -  Circuit / schematic (added 02/05)
IR Digital Thermostat for FAN -  ….(electronic schematic added 08/08) [Site is under construction right now]
IR Remote Control Tester -  Gadget Freak Case 147:  Couch potatoes should be particularly interested in Bill Bowden's remote control IR receiver, which allows users to control the power of virtually any electrical appliance (including those not equipped for remote) using their standard remote control. It's based on an IR receiver circuit,
IR Remote Control Tester -  A simple IR receiver to facilitate in testing of Infra Red Remote Control handsets…. [Circuit design by Andy Collison]
IR Remote Volume Controller -  ….
IR Remote-Control Checker -  Suitable for any Infra-red emitting device.  3V battery supply  ....
IRDCiP1202-A 300kHz Dual 15A 5.5VIN to 13.2VIN Dual Output Synchronous Buck Converter using iP1202 -  This board allows engineers to easily evaluate the iP1202 in an independent and parallel configuration that is capable of providing up to 15A per phase with double-sided heat sinking.  (added 3/05)
IRDCiP2001-A 500kHz 40A 2-phase Synchronous Buck Converter using iP2001 -  This board enables engineers to easily evaluate the iP2001 in a 2-phase configuration that is capable of providing up to 40A in a lab environment without airflow.  (added 3/05)
IrOn-Off -  …....
Isolated Ac Current Monitor -  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 amps of AC current and provides at least 500vac of isolation.  With the components shown, the output AC voltage is scaled so 1 amp of current produces 100mv of AC voltage.... [Designed by David A. Johnson]
Isolated circuit monitors ac line -  5-Jul-07 Issue of EDN  A simple circuit develops a square wave whose pulse width is proportional to the mains-voltage level.... [Design Idea by David Williams, Millington, MI]
Isolated clock source acts as test generator -  19-Mar-09 Issue of EDN  A cost-effective approach to implementing an isolated clock source uses a high-speed optocoupler with low input-to-output capacitance.... [Design Idea by Daniele Danieli, Eurocom-Pro, Venice, Italy]
Isolated Probe -  This probe allows connecting to such 'floating' circuits to a normal scope input.  As seen in the circuit, it is based on using an optocoupler.  The one shown in the diagram is a dual unit, but I had a pile of them here, so thats what I used. …....) [Luhan Monat - Mesa Arizona]
Jitter Measurement Techniques -  Pericom Semiconductor Application Brief # 036 (app note added 2/05)
Jitter Measurements using Eye Patterns Test Report #1 -  National Semiconductor Application Note  (app note added 2/06)
Keys finder -  The ear and mouth of the circuit is a piezoelectric buzzer. Fizzling in a frequency of 3....4 KHz produced sound waves that piezoelectric buzzer converts them to an oscillation.  This oscillation passes thought C1 and thought inverters N1....N3.The inverters along with R1 and R2, compose an amplifier with gain 400 ! .The C8 and C9 stabilize and reduce the signal's level.…....


Testers:  #'s    A-B    C    D    E    F-G    H-K    L    M-O    P    Q-R    S    T     U    V-Z
 
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