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Tester or Measurement (Instrument) Circuits

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Last Updated: November 21, 2017 05:45 AM

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:

Hall effect Current sensing -  How do simply incorporate constant power throttle __ Designed by Richard Torrens

Hall Effect Gaussmeter -  Have you ever wanted to find out how strong a magnet really was, or how the strength of the magnetic field varied as you changed the distance from the magnet or the temperature of the magnet, or how well a shield placed in front of the magnet worked?  Voltmeters are fairly inexpensive and easy to find, but where do you purchase a Gaussmeter (also known as a magnetometer).   I built a hand-held Gaussmeter for measuring the polarity and strength of a magnetic field.   it uses a linear Hall effect device and some op-amps and resistors and things from Radio Shack.   __ Designed by Rick Hoadley

Handheld 2.4 GHz Spectrum Analyzer. Part 1 -  After visiting some web pages about 2.4 GHz iSM band spectrum analyzers based on the CYWM6935 module, I tried to build my own analyzer, but with some improvements.  The references I found on the net used the parallel port or a __ Designed by Miguel A. Vallejo

Handheld 2.4 GHz Spectrum Analyzer. Part 2 -  The software The software is written in C using avк-gcc under Windows (WinAVR).  LCD routines are based on FandI Gunawan's Nokia 3310 routines and CYWM6935 routines are based on the code of Jason Hecker (see at the bottom for __ Designed by Miguel A. Vallejo

Hand-Held Metal Locator -  ideal for finding steel frames and studs, steel bracing and nails in plaster walls, this Metal Locator can also show the length of the tang in knife handles, screwdrivers and other tools.  As well, it can discriminate between ferrous and non-ferrous metals.__ SiliconChip

Hand-to-Hand Body Composition Meter Reference Design with BLE Connectivity -  This reference design is for a complete hand-held body composition or fat loss monitor end equipment featuring TI signal chain, power, and connectivity components. With Tis AFE4300 body composition AFE, you can accelerate your body composition design to develop more quickly. This reference design also includes the full BLE connectivity design for easy interface to BLE enabled smartphones, tablets, etc.__ Texas Instruments

Handy Tester -  For beginners, heres a low-cost multitester that can be used to test the condition of almost all the electronic components from resistors to IC s.  it uses only a few components but...__ Electronics Projects for You

Handy Zener Diode Tester -  Here is a handy zener diode tester which tests zener diodes with breakdown voltages extending up to 120 volts.  The main advantage of this circuit is that it works with a...__ Electronics Projects for You

Hardware Histogram Speeds ADC Test -  11/13/03  EDN Design Ideas:  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 expe __ Circuit Design by Tony Zizzo Jr, Texas Instruments, Tucson, AZ

HC-11 Evaluation Board -  Build a low-cost evaluation board for Motorola 68HC11.  Downloadable BUFFALO V3.4 to 32kB SRAM for learning __ Designed by Wichit Sirichote

Hearing Aid -  This low-cost, general-purpose electronic hearing aid works off 3V DC (2x1.5V battery).in this circuit, transistor T1 and associated components form the audio signal preamplifier for the acoustic signals picked up by...__ Electronics Projects for You

Heart rate measurement from fingertip. Part 1. Schematic -  introduction Heart rate measurement indicates the soundness of the human cardiovascular system.  This project demonstrates a technique to measure the heart rate by sensing the change in blood volume in a finger artery while the heart is pumping the__ 

Heart rate measurement from fingertip. Part 2. Software -  Part 1.  Schematic Software The firmware does all the control and computation operation.  in order to save the power, the sensor module is not activated continuously.  instead, it is turned on for 15 sec only once the start button is pressed.  The__ 

Heart Rate Monitor based on a dual op-amp IC -  Strictly speaking, this simple circuit shouldn't work!  How could anyone expect an ordinary light dependent resistor photo cell to 'see' through a fingertip in natural daylight and detect the change in blood flow as the heart pulsates? The secret is a high gain circuit, based on a dual op amp IC which can be either the low power LM358 or the JFET TL072.  __ Learning Electronics

Heart rate sensor -  Medical and health related electronic circuit diagrams / circuit schematics__ 

Heartbeat Sensor (Tranduscer) -  To build a heart-beat transducer not as difficult as imagined.  Circuit below shows a simple heart-beat transducer.__ 

Heartbeat transducer using infrared LED / Detector -  Medical and health related electronic circuit diagrams / circuit schematics__ 

Heat Control Unit -  This circuit will turn the heater on when the temperature of water falls below the lower limit set by you and turn it off when the temperature increases above the higher...__ Electronics Projects for You

Heat Sensitive Switch -  At the heart of this heat-sensitive switch is IC LM35 (IC 1) , which is a linear temperature sensor and linear temperature-to-voltage converter circuit.  The converter provides accurately linear and directly proportional output signal in millivolts over the temperature range of 0C to 155C.  it develops an output voltage of 10 mV per degree centigrade change in__ 

Heat Sensor -  The Thermistor, or NTC (Tony van Roon's Negative Temperature Coefficient) of 10K, is a standard type.  Most types will work.  The one in the diagram is a 10K model made by Fenwal (Tony van Roon's #197-103LAG-A01)  __ Designed by Tony van Roon  VA3AVR

Heath EU-14A Special Experimental Parts specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUP-26 VOM specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-16 Voltage Reference Source specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-17 Transistor Power Supply specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-19A Operational Amplifier System specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-20A Servo-Recorder specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-24 VTVM specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-25 DC Oscilloscope specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heath EUW-27 Sine-Square Wave Generator specs & schematic -  Circuit Only __ Designed by HEATH KIT

Heathkit AV-1 AC voltmeter -  Schematic Only__ 

Heathkit G-5 Signal generator -  Schematic Only__ 

Heathkit Groundtrack GR-1290 VLF metal Detector & Detector coil construction notes -  Schematic Only, no circuit description __ Designed by hobbyteam @ hobby-hour.com

Heathkit HD-1 harmonic distortion analyzer schematic -  Circuit Only__ 

Heathkit HD-1250 solid-state dipper schematic -  Circuit Only__ 

Heathkit HM-10A Tunnel Dipper -  Schematic Only__ 

Heathkit IB-2 impedance bridge schematic -  Schematic Only__ 

Heathkit IM-18 VTVM schematic (similar to Most other Heath VTVMs) -  Circuit Only __ Designed by HEATH KIT

Heathkit IP-17 0-400V regulated power supply schematic -  Circuit Only __ Designed by HEATH KIT

Heathkit IP-27 LV regulated power supply -  Schematic Only__ 

Heathkit RC-1 Radiation Counter partial manual -  Vintage schematic__ 

Heat-Sensitive Switch -  At the heart of this heat-sensitive switch is IC LM35 (IC 1) , which is a linear temperature sensor and linear temperature-to-voltage converter circuit.  The converter provides accurately linear and directly proportional output signal...__ Electronics Projects for You

Hewlett-Packard 206A AF oscillator schematic  -  Circuit Only __ Designed by Hewlett-Packard

Hewlett-Packard 400 AF VTVM manual w/schematic -  Circuit Only __ Designed by Hewlett-Packard

HF AC Millivoltmeter adapter -  intended for use past 200 kHz, this adapter changes HF AC voltages between 2 mv P-P and 200 mv P-P to the corresponding DC level with linearity of better  than 1 millivolt.  A on-board calibration signal aids in calibration prior to use.   __ Designed by Dick Cappels

HF/VHF/UHF Test Oscillator -  This test oscillator covers 16 MHz to 300 MHz in six bands, using varactor tuning.  it has a high level output to drive a frequency meter and two sine wave outputs, one of which is 50 Ohms. 
This article was published in Croatian in infoelektronika magazine in June, 2012 (cooperatively)  __ Designed by Dick Cappels

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 __ Contact IQ Technologies

High Accuracy Current Sense Amplifier Enables Current Sensing & Current Sharing -  APP 391: Mar 01, 2001 Current sharing between DC/DC converter modules enables several modules to be paralleled.  in recent years, tight tolerances for current sharing have made discrete current-sense Circuit designs a formidable challenge.  This App Note describes a low-cost, space-saving and accurate current sensing and sharing scheme using MAX4372.  __ Maxim Integrated

High Accuracy Impedance Measurements using 12-Bit Impedance Converters  -  The software used is the same software that is available with evaluation boards and is accessible from the AD5933 and AD5934 product pages.  , Example 1: Low impedance Range , Table 1__ Analog Devices from the Lab

High Capacity Alternative to 9 Volt Battery -  Get ten times the capacity of a 9 Volt battery to power your devices.   __ Designed by REUK-Renewable Energy UK website

High Current, High Voltage Battery Capacity Meter -  ideal for solar power battery monitoring but also perfect for a wide variety of rechargeable battery applications, this smart battery meter monitors the charge and discharge of lead-acid, NIC ad and NiMH
batteries with an operating voltage range of 9-60V and currents up to 80A.  it has settable overload and under-voltage protection and it can be connected to a PC for logging of battery condition.__ SiliconChip

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Test Equipment:  #'s - A        B - D        E - G
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