{"id":44,"date":"2008-09-25T05:06:59","date_gmt":"2008-09-25T09:06:59","guid":{"rendered":"http:\/\/itp.indiamos.com\/blog\/?p=44"},"modified":"2008-09-25T05:12:15","modified_gmt":"2008-09-25T09:12:15","slug":"physcomp-lab-week-3-electronics","status":"publish","type":"post","link":"https:\/\/itp.indiamos.com\/blog\/2008\/09\/25\/physcomp-lab-week-3-electronics\/","title":{"rendered":"PhysComp lab, week 3: Electronics"},"content":{"rendered":"<p>This week&#8217;s PhysComp lab looked pretty straightforward, but that&#8217;s only if you don&#8217;t take into account my singular gift for turning LEDs backward and mixing up power and ground on the breadboard.<a href=\"http:\/\/itp.indiamos.com\/blog\/2008\/09\/25\/physcomp-lab-week-3-electronics\/#note\">*<\/a><\/p>\n<p>So, first, there was the obligatory soldering. It wasn&#8217;t quite so bad this time, I think, though I did manage to melt some of the plastic inside the jack.<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886417503\/\" title=\"Soldering the DC power jack by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i0.wp.com\/farm4.static.flickr.com\/3003\/2886417503_39579359d5.jpg?resize=400%2C300\" width=\"400\" height=\"300\" alt=\"Soldering the DC power jack\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>Then I had a lot of puzzlement over the high <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887252212\/in\/set-72157607212375323\/\">voltage<\/a> <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887252786\/in\/set-72157607212375323\/\">readings<\/a> I was getting. And there was a burning smell, even though I&#8217;d turned off the soldering iron ten minutes before. Hmm. Could there be something wrong with the&#8212;<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886418587\/\" title=\"Ice used after I made the mistake of touching the voltage regulator by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i0.wp.com\/farm4.static.flickr.com\/3263\/2886418587_fa13842e25.jpg?resize=400%2C300\" width=\"400\" height=\"300\" alt=\"Ice used after I made the mistake of touching the voltage regulator\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p><strong>Handy Tip:<\/strong> Voltage regulators get really fucking hot. Don&#8217;t touch them.<\/p>\n<p>Finally, I found the wire that was going into ground instead of power and got <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887253052\/in\/set-72157607212375323\/\">the desired voltage reading<\/a>. Then, I added a switch and an LED.<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887252504\/\" title=\"Breadboard with power jack, voltage regulator, push-button switch, and LED by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i0.wp.com\/farm4.static.flickr.com\/3064\/2887252504_1e469f9afc.jpg?resize=400%2C300\" width=\"400\" height=\"300\" alt=\"Breadboard with power jack, voltage regulator, push-button switch, and LED\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>And, again, wired the switch into ground instead of power. Got that sorted, and&#8212;<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887253324\/\" title=\"Pressing the switch to light the LED by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i1.wp.com\/farm4.static.flickr.com\/3218\/2887253324_19075935dc.jpg?resize=400%2C300\" width=\"400\" height=\"300\" alt=\"Pressing the switch to light the LED\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>Ta da!<\/p>\n<p>The next step, putting two LEDs in series, <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887253796\/in\/set-72157607212375323\">went fine<\/a> (with voltage readings of 2.11 for the red LED and 2.88 for the green), but when the instructions said to add a third . . . well, I&#8217;m not sure how you add a third LED in series. Is it like this&#8212;<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886420343\/\" title=\"How do you put three LEDs in series? by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i1.wp.com\/farm4.static.flickr.com\/3280\/2886420343_ce7f39bbf0.jpg?resize=400%2C300\" width=\"400\" height=\"300\" alt=\"How do you put three LEDs in series?\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>Probably not, since that wiring scheme <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886420489\/in\/set-72157607212375323\/\">works<\/a>, while the instructions imply that adding a third LED makes them all go out. Comparing my voltage numbers here would probably tell me the answer to this question, but although I took lots of photos to record the multimeter readings, I can&#8217;t remember which reading was from which part of the circuit or taken at which step. Sigh. I should have just written them down.<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886420887\/in\/set-72157607212375323\/\">Setting the LEDs in parallel<\/a> was also pretty easy, but measuring the amperage across them was simply not happening. I tried it every which way, but I couldn&#8217;t get the circuit closed with the multimeter as part of it. After trying several interpretations of the written instructions and circuit diagram, I gave up and moved on to the pot part.<\/p>\n<p><a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2887254790\/\" title=\"Breadboard with potentiometer and LED by indiamos, on Flickr\"><img loading=\"lazy\" src=\"https:\/\/i2.wp.com\/farm4.static.flickr.com\/3032\/2887254790_8f95757f82.jpg?resize=300%2C400\" width=\"300\" height=\"400\" alt=\"Breadboard with potentiometer and LED\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p>Again, no problem wiring it. The voltage readings were 1.78 at about halfway and 2.89 at full blast.<\/p>\n<p>This lab took me about four hours, sadly.<\/p>\n<p><a name=\"note\"><\/a><span class=\"note\" style=\"font-size:smaller;\">*  The reason for the latter, in my defense, is that the breadboard in my kit has ground on the outside rows, while the breadboard in all the photos within <a href=\"http:\/\/itp.nyu.edu\/physcomp\/Labs\/Electronics\">the instructions<\/a> has power on the outside. I always forget to check the color of the row, matching only the position. And sometimes I&#8217;m just <a href=\"http:\/\/www.flickr.com\/photos\/indiamos\/2886417733\/in\/set-72157607212375323\/\">not paying attention<\/a>.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This week&#8217;s PhysComp lab looked pretty straightforward, but that&#8217;s only if you don&#8217;t take into account my singular gift for turning LEDs backward and mixing up power and ground on the breadboard.* So, first, there was the obligatory soldering. It wasn&#8217;t quite so bad this time, I think, though I did manage to melt some &hellip; <a href=\"https:\/\/itp.indiamos.com\/blog\/2008\/09\/25\/physcomp-lab-week-3-electronics\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">PhysComp lab, week 3: Electronics<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[11,4,8,6],"tags":[],"jetpack_featured_media_url":"","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p3qY10-I","_links":{"self":[{"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/posts\/44"}],"collection":[{"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/comments?post=44"}],"version-history":[{"count":8,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/posts\/44\/revisions"}],"predecessor-version":[{"id":52,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/posts\/44\/revisions\/52"}],"wp:attachment":[{"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/media?parent=44"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/categories?post=44"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itp.indiamos.com\/blog\/wp-json\/wp\/v2\/tags?post=44"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}