http://www.raspberryvi.org/enContents © 2021-03-10 09:37 <a href="mailto:mike@raspberryvi.org">Mike Ray</a> <a rel="license"> <p>Unless otherwise stated all content released under the <a href="http://creativecommons.org/licenses/by-nc-sa/4.0/"> <img alt="Creative Commons License BY-NC-SA" style="border-width:0; margin-bottom:0px;" src="http://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png"> </a> </p> Wed, 10 Mar 2021 09:37:13 GMTNikola (getnikola.com)http://blogs.law.harvard.edu/tech/rsshttp://www.raspberryvi.org/posts/power-equations.htmlMike Ray<div><h3 class="no_toc" id="table-of-contents">Table of Contents</h3> <ul id="markdown-toc"> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#introduction" id="markdown-toc-introduction">Introduction</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#the-units-of-measure" id="markdown-toc-the-units-of-measure">The Units of Measure</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#power" id="markdown-toc-power">Power</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#voltage" id="markdown-toc-voltage">Voltage</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#current" id="markdown-toc-current">Current</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#a-triplet-of-equations" id="markdown-toc-a-triplet-of-equations">A Triplet of Equations</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#simple-example" id="markdown-toc-simple-example">Simple Example</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#how-big-does-my-resistor-have-to-be" id="markdown-toc-how-big-does-my-resistor-have-to-be">How Big Does My Resistor Have to be?</a></li> <li><a href="http://www.raspberryvi.org/posts/power-equations.html#its-a-law-jim-but-not-as-we-know-it" id="markdown-toc-its-a-law-jim-but-not-as-we-know-it">Its a Law Jim, but not as we Know it</a></li> </ul> <h3 id="introduction">Introduction</h3> <p>In this blog post I will attempt to explain another triplet of equations that are very important to electronic theory.</p> <p>These are the three equations we can use to calculate power, in Watts, when we know Voltage and current, Voltage when we know power and current, or current when we know power and voltage.</p> <p><a href="http://www.raspberryvi.org/posts/power-equations.html">Read more…</a> (3 min remaining to read)</p></div>electronicstheoryhttp://www.raspberryvi.org/posts/power-equations.htmlTue, 09 Mar 2021 07:18:00 GMThttp://www.raspberryvi.org/posts/battery-iron-soldering.htmlMike Ray<div><p>I've been doing hobby electronics since I was first old enough to be trusted with a soldering iron and not to burn myself, or burn the house down.</p> <p>So, after I lost my sight, soldering became a problem and a very upsetting loss.</p> <p>I have only recently felt very strongly that I wanted to find a way of doing some sensible soldering and hobby electronics again.</p> <p>I acknowledge that I am not going to be soldering QFP surface-mount SoC chips or MCUs any time soon. But I have found some techniques which mean I can now manage most of the typical old 0.54mm (0.1 inch) pitch through-hole components and boards.</p> <p><a href="http://www.raspberryvi.org/posts/battery-iron-soldering.html">Read more…</a> (3 min remaining to read)</p></div>electronicssolderinghttp://www.raspberryvi.org/posts/battery-iron-soldering.htmlWed, 03 Mar 2021 22:04:35 GMThttp://www.raspberryvi.org/posts/smith-kettlewell.htmlMike Ray<div><p>The <a href="https://www.ski.org/smith-kettlewell-technical-file/">Smith-Kettlewell Technical File</a> was a file published between 1980 and 1998, for blind and visually-impaired electronics professionals and enthusiasts.</p> <p>It contains a great amount of electronic data.</p> <p><a href="http://www.raspberryvi.org/posts/smith-kettlewell.html">Read more…</a> (1 min remaining to read)</p></div>componentselectronicslinkshttp://www.raspberryvi.org/posts/smith-kettlewell.htmlSun, 28 Feb 2021 11:53:40 GMThttp://www.raspberryvi.org/posts/capacitors-in-series-and-parallel.htmlMike Ray<div><p>This post explains how to calculate the value of the overall capacitance of more than one capacitor, both in series and in parallel.</p> <p>Capacitors have limited application in digital circuits, including those we might use in conjunction with either a <a href="https://www.raspberrypi.org/">Raspberry Pi</a> or some variety of microcontroller.</p> <p>But you will find them as the second component in a classic RC timing circuit, where a capacitor is charged through a resistor, to produce some kind of event after a predictable length of time, or in decoupling noise (ripple) to ground.</p> <p>Where capacitors are also often used is in a DC blocking application. To couple AC, such as audio or radio frequency into the next stage of a circuit, but block the DC from the previous stage.</p> <p><a href="http://www.raspberryvi.org/posts/capacitors-in-series-and-parallel.html">Read more…</a> (1 min remaining to read)</p></div>componentselectronic theoryelectronicshttp://www.raspberryvi.org/posts/capacitors-in-series-and-parallel.htmlSat, 27 Feb 2021 08:51:55 GMThttp://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.htmlMike Ray<div><h3 class="no_toc" id="table-of-contents">Table of Contents</h3> <ul id="markdown-toc"> <li><a href="http://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.html#introduction" id="markdown-toc-introduction">Introduction</a></li> <li><a href="http://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.html#supported-meters" id="markdown-toc-supported-meters">Supported Meters</a></li> <li><a href="http://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.html#uni-t-ut60a-meter-example-command" id="markdown-toc-uni-t-ut60a-meter-example-command">Uni-T UT60A Meter Example Command</a></li> <li><a href="http://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.html#example-output" id="markdown-toc-example-output">Example Output</a></li> </ul> <p><a href="http://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.html">Read more…</a> (2 min remaining to read)</p></div>electronicssigroktest equipmenthttp://www.raspberryvi.org/posts/sigrok-cli-multimeter-example.htmlFri, 26 Feb 2021 08:20:39 GMThttp://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.htmlMike Ray<div><h3 class="no_toc" id="table-of-contents">Table of Contents</h3> <ul id="markdown-toc"> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#introduction" id="markdown-toc-introduction">Introduction</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#logic-levels-and-gpio-pin-states" id="markdown-toc-logic-levels-and-gpio-pin-states">Logic Levels and GPIO Pin States</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#a-potential-divider" id="markdown-toc-a-potential-divider">A Potential Divider</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#resistor-and-button-as-potential-divider" id="markdown-toc-resistor-and-button-as-potential-divider">Resistor and Button as Potential Divider</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#the-circuit" id="markdown-toc-the-circuit">The circuit</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#short-circuit" id="markdown-toc-short-circuit">Short Circuit</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#limiting-current-flow" id="markdown-toc-limiting-current-flow">Limiting Current Flow</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#the-whole-circuit" id="markdown-toc-the-whole-circuit">The whole circuit</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#pull-down" id="markdown-toc-pull-down">Pull-down</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#switch-contact-bounce" id="markdown-toc-switch-contact-bounce">Switch Contact Bounce</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#internal-pull-up-and-pull-down-resistors" id="markdown-toc-internal-pull-up-and-pull-down-resistors">Internal pull-up and pull-down Resistors</a></li> <li><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html#edge-triggering" id="markdown-toc-edge-triggering">Edge-triggering</a></li> </ul> <p><a href="http://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.html">Read more…</a> (7 min remaining to read)</p></div>electronicsGPIORaspberry Pihttp://www.raspberryvi.org/posts/pull-up-and-pull-down-resistors.htmlThu, 25 Feb 2021 12:53:21 GMT