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Introduction In my last post I described a simple circuit that produced a reasonably accurate 10 mA current source to allow measurement of DC resistance down into the milliohm range.  I received  a number of helpful suggestions on how to improve the circuit as well as great discussion on selecting precision parts.  This post will outline several approaches I have considered on how to proceed.  As a refresher, here are the design objectives originally posted: Inexpensive Can ...
Introduction I was inspired by a recent post from shabaz on Building Kelvin (4-Wire) Test Leads.  Shabaz explains in detail and with clarity why measurement of small resistances with the two leads on a multimeter is difficult.  This got me to thinking about how I might build my own 4-wire Kelvin instrument.  This post will describe initial tests of a simple current source that can be used with a digital multimeter to more accurately measure small resistances.   Method and ...
In this blog I intend to outline a reasonably simple way to control Wi-Fi enabled Arduino compatible boards and single board computers like the Raspberry Pi or Beaglebone.  In addition an Apple or Android device that can run the Google Assistant app is needed.   Introduction   I have been thinking about this for a while and there are a number of approaches.  For example, two Ben Heck episodes Part 1 and Part 2  automated the workbench with voice control using Alexa. ...