{"id":7,"date":"2010-09-12T07:12:00","date_gmt":"2010-09-12T07:12:00","guid":{"rendered":"http:\/\/www.mariarabinovich.com\/physcomp\/?p=7"},"modified":"2011-02-05T17:53:44","modified_gmt":"2011-02-05T17:53:44","slug":"blinking-leds-lab","status":"publish","type":"post","link":"http:\/\/www.mariarabinovich.com\/blog\/archives\/7","title":{"rendered":"Blinking LEDs Lab"},"content":{"rendered":"

The lights lit up. It was amazing. Luckily I caught it on camera.<\/p>\n

[wpvideo 3qSfZelv]<\/p>\n

Going back over this lab, I was trying to figure out how the circuit works. I read that electrons actually flow from ground to power, despite the conception that current flows toward ground. So I was trying to visualize the part that confuses me: Why the circuit is not a simple loop, interrupted by a switch. Instead the current seems to have two parts, bridged by the 10K resistor. \u00a0This is the circuit that would make sense to me,<\/p>\n

\"\"<\/a><\/p>\n

and here is the way I think I would draw the actual circuit.<\/p>\n

\"\"<\/a><\/p>\n

I think this is parallel, and the one I imagined is series??? Also, I realize that the micro controller breaks up the circuit, has resistance, so maybe displaying it this way is meaningless, and maybe its completely separate circuits???<\/p>\n

\"\"<\/a><\/p>\n

But I want to understand why the 10K resistor is necessary.<\/p>\n

And it works without the 10K resistor, except for a delay when the switch is released: the LED remains on HIGH for several seconds. When I reinsert the 10K resistor with the ground leg first, the program works as intended. But when I inserted the switch-side leg of the resistor first, I noticed that the LED lit up when I touched the other leg. I don’t know what kind of circuit issue this is, but I was thinking that maybe that I conduct some electrons away from the resistor, and so the electrons are free to flow into the resistor until it fills up.<\/p>\n

[wpvideo mIfN6XOH]<\/p>\n","protected":false},"excerpt":{"rendered":"

1st PhysComp lab<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,24,1],"tags":[],"class_list":["post-7","post","type-post","status-publish","format-standard","hentry","category-labs","category-physical-computing","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/comments?post=7"}],"version-history":[{"count":15,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":418,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/posts\/7\/revisions\/418"}],"wp:attachment":[{"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/media?parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/categories?post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mariarabinovich.com\/blog\/wp-json\/wp\/v2\/tags?post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}