{"id":434,"date":"2018-10-03T16:17:50","date_gmt":"2018-10-03T16:17:50","guid":{"rendered":"http:\/\/blogs.plymouth.ac.uk\/embedded-systems\/?page_id=434"},"modified":"2018-10-03T16:17:50","modified_gmt":"2018-10-03T16:17:50","slug":"light-dependent-resistor-ldr-glossary-entry","status":"publish","type":"page","link":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/glossary-2\/light-dependent-resistor-ldr-glossary-entry\/","title":{"rendered":"Light Dependent Resistor (LDR) &#8211; (Glossary Entry)"},"content":{"rendered":"<p>The light dependent resistor (LDR), or photo-resistor, is a variable resistor that depends on incident light (as opposed to the position of a shaft in a potentiometer).<span class=\"Apple-converted-space\">\u00a0<\/span><\/p>\n<p>The resistance decreases as light is increased. In the dark, resistances in the order of <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/ql-cache\/quicklatex.com-bedf32a5c64901a3b60d7bbe6a803f4f_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#77;&#32;&#92;&#79;&#109;&#101;&#103;&#97;\" title=\"Rendered by QuickLaTeX.com\" height=\"12\" width=\"31\" style=\"vertical-align: 0px;\"\/>\u00a0can be achieved. In very bright light, resistances are in the order of 100s of <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/ql-cache\/quicklatex.com-ec0c546b6596f336d8e1d41bb064b951_l3.png\" class=\"ql-img-inline-formula quicklatex-auto-format\" alt=\"&#92;&#79;&#109;&#101;&#103;&#97;\" title=\"Rendered by QuickLaTeX.com\" height=\"12\" width=\"12\" style=\"vertical-align: 0px;\"\/>.<\/p>\n<figure id=\"attachment_435\" aria-describedby=\"caption-attachment-435\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-435\" src=\"http:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Symbols.png\" alt=\"\" width=\"450\" height=\"266\" srcset=\"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Symbols.png 787w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Symbols-300x178.png 300w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Symbols-768x455.png 768w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><figcaption id=\"caption-attachment-435\" class=\"wp-caption-text\">Symbol and illustration of a Light Dependent Resistor (LDR)<\/figcaption><\/figure>\n<p>Used in a potential divider circuit, a simple light-to-voltage can be created.<\/p>\n<figure id=\"attachment_436\" aria-describedby=\"caption-attachment-436\" style=\"width: 450px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-436\" src=\"http:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit.png\" alt=\"\" width=\"450\" height=\"407\" srcset=\"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit.png 1225w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit-300x271.png 300w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit-768x695.png 768w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit-1024x926.png 1024w, https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-content\/uploads\/sites\/94\/2018\/10\/LDR-Circuit-1104x999.png 1104w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><figcaption id=\"caption-attachment-436\" class=\"wp-caption-text\">Using an LDR within a potential divider circuit to generate a light dependent voltage.<\/figcaption><\/figure>\n<p>The resistance is also dependent on temperature, so these devices are not ideally suited to accurate measurement or instrumentation.<\/p>\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Photoresistor\">https:\/\/en.wikipedia.org\/wiki\/Photoresistor<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The light dependent resistor (LDR), or photo-resistor, is a variable resistor that depends on incident light (as opposed to the position of a shaft in a potentiometer).\u00a0 The resistance decreases as light is increased. In the dark, resistances in the order of \u00a0can be achieved. In very bright light, resistances are in the order of&hellip; <a class=\"more-link\" href=\"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/glossary-2\/light-dependent-resistor-ldr-glossary-entry\/\">Continue reading <span class=\"screen-reader-text\">Light Dependent Resistor (LDR) &#8211; (Glossary Entry)<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":153,"menu_order":70,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-434","page","type-page","status-publish","hentry","entry"],"_links":{"self":[{"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/pages\/434","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/comments?post=434"}],"version-history":[{"count":1,"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/pages\/434\/revisions"}],"predecessor-version":[{"id":437,"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/pages\/434\/revisions\/437"}],"up":[{"embeddable":true,"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/pages\/153"}],"wp:attachment":[{"href":"https:\/\/blogs.plymouth.ac.uk\/embedded-systems\/wp-json\/wp\/v2\/media?parent=434"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}