{"id":430,"date":"2018-11-15T09:51:18","date_gmt":"2018-11-15T14:51:18","guid":{"rendered":"https:\/\/espacerm.com\/webgen\/?page_id=430"},"modified":"2018-11-24T12:35:02","modified_gmt":"2018-11-24T17:35:02","slug":"le-diviseur-de-tension-resistif","status":"publish","type":"page","link":"https:\/\/espacerm.com\/webgen\/le-diviseur-de-tension-resistif\/","title":{"rendered":"Le diviseur de tension r\u00e9sistif"},"content":{"rendered":"\n<p>Dans certaines situations, il faut r\u00e9duire la tension, car elle est trop \u00e9lev\u00e9e pour notre utilisation. La m\u00e9thode pr\u00e9sent\u00e9e ici consiste \u00e0 placer deux r\u00e9sistances en s\u00e9rie et de se relier aux bornes de la r\u00e9sistance relier au n\u00e9gatif de la pile.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"736\" height=\"384\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/diviseur-de-tension_05.jpg\" alt=\"\" class=\"wp-image-431\" srcset=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/diviseur-de-tension_05.jpg 736w, https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/diviseur-de-tension_05-300x157.jpg 300w\" sizes=\"(max-width: 736px) 100vw, 736px\" \/><\/figure>\n\n\n\n<p>Les formules applicables dans cette situation sont<\/p>\n\n\n\n<figure class=\"wp-block-image is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-4.png\" alt=\"\" class=\"wp-image-544\" width=\"452\" height=\"155\" srcset=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-4.png 580w, https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-4-300x103.png 300w\" sizes=\"(max-width: 452px) 100vw, 452px\" \/><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><strong>V<\/strong> : Voltage,<em> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<\/em><strong>I <\/strong>: Courant \u00e9lectrique,&nbsp; &nbsp; &nbsp; &nbsp;<strong>R<\/strong> : R\u00e9sistance&nbsp; &nbsp;<strong>P<\/strong> : Puissance&nbsp;<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"508\" height=\"127\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-8.png\" alt=\"\" class=\"wp-image-556\" srcset=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-8.png 508w, https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-8-300x75.png 300w\" sizes=\"(max-width: 508px) 100vw, 508px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"214\" height=\"107\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-9.png\" alt=\"\" class=\"wp-image-561\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"490\" height=\"43\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-17.png\" alt=\"\" class=\"wp-image-579\" srcset=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-17.png 490w, https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-17-300x26.png 300w\" sizes=\"(max-width: 490px) 100vw, 490px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"242\" height=\"104\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-16.png\" alt=\"\" class=\"wp-image-578\"\/><\/figure>\n\n\n\n<p>Que vaux la somme de Va + Vb ?<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"224\" height=\"124\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-19.png\" alt=\"\" class=\"wp-image-582\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"192\" height=\"67\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-22.png\" alt=\"\" class=\"wp-image-586\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"158\" height=\"83\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-24.png\" alt=\"\" class=\"wp-image-588\"\/><\/figure>\n\n\n\n<p><em><strong>EXEMPLE 1 : Vs = 12.6v , Ra = 100Kohms, valeur d\u00e9sir\u00e9e de Vb 2,2 <\/strong><\/em><strong>v&nbsp;<\/strong><br>(Remarque : 12,6 V est la valeur maximale pour une pile Lipo 3S)&nbsp;<\/p>\n\n\n\n<p>Quel sera la valeur de Rb ?<\/p>\n\n\n\n<p>Quel sera la valeur de Va ?<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"214\" height=\"107\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-10.png\" alt=\"\" class=\"wp-image-562\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"266\" height=\"484\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-11.png\" alt=\"\" class=\"wp-image-563\" srcset=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-11.png 266w, https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-11-165x300.png 165w\" sizes=\"(max-width: 266px) 100vw, 266px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"198\" height=\"127\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-12.png\" alt=\"\" class=\"wp-image-564\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"189\" height=\"86\" src=\"https:\/\/espacerm.com\/webgen\/wp-content\/uploads\/2018\/11\/image-15.png\" alt=\"\" class=\"wp-image-569\"\/><\/figure>\n\n\n\n<p><strong>Truc<\/strong> : coller directement ces formules dans Google, il affichera la r\u00e9ponse<br>100\/((12,6\/2,2)-1))&nbsp; &nbsp;ou&nbsp; &nbsp; 100000ohms\/((12,6volts\/2,2volts)-1))<\/p>\n\n\n\n<p>Il est simple apr\u00e8s d&rsquo;entrer de nouvelles valeurs pour diff\u00e9rents sc\u00e9narios<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><strong>Rb = 21,15Kohms<\/strong><\/p>\n\n\n\n<p>Va = Vs -Vb -&gt; Va = 12,6V -2,2V<\/p>\n\n\n\n<p><strong>Va = 10,4V<\/strong><\/p>\n\n\n\n<p><em><strong>EXEMPLE 2&nbsp;: Ra = 100Kohms, Rb = 22Kohms,&nbsp;  Vb 3.3v<\/strong><\/em><strong>&nbsp;<\/strong><\/p>\n\n\n\n<p>Quelle est le voltage Vs ?<\/p>\n\n\n\n<p>I = V\/R =&gt; I = Vb\/Rb =&gt; I = 3,3V\/22000ohms<\/p>\n\n\n\n<p>I = 0.00015 Amp\u00e8re<\/p>\n\n\n\n<p>V = R*I =&gt;&nbsp;Vs = Rt * I =&gt; Vs = (100000ohms+22000ohms) * 0,00015A<\/p>\n\n\n\n<p><strong>Vs = 18.3V<\/strong><\/p>\n\n\n\n<p><em><strong>EXEMPLE 3&nbsp;: Vb 3.3v , Rb = 22Kohm<\/strong><\/em><\/p>\n\n\n\n<p>Quelle est la puissance \u00e0 support\u00e9e par la r\u00e9sistance Rb ?<\/p>\n\n\n\n<p>P = V * I<\/p>\n\n\n\n<p>P = V * (V\/R)<\/p>\n\n\n\n<p>Pb = Vb*Vb\/Rb<\/p>\n\n\n\n<p>Pb = 3,3V * 3,3V \/ 22000ohms<\/p>\n\n\n\n<p><strong>Pb = 0.000495 watt<\/strong><\/p>\n\n\n\n<p><em><strong>EXEMPLE 4&nbsp;: Vs = 18.3 V, Ra = 100Kohms, Vb 3.3v , Rb = 22Kohms<\/strong><\/em><\/p>\n\n\n\n<p>Quelle est la puissance \u00e0 support\u00e9e par la r\u00e9sistance de 100Kohms?<\/p>\n\n\n\n<p>Pa = Va Ia<\/p>\n\n\n\n<p>Va = Ra Ia<\/p>\n\n\n\n<p>Pa = Ra * Ia * Ia<\/p>\n\n\n\n<p>Ia = Vs \/( Ra + Rb) =&gt; Ia = 18.3V\/(100000ohms+22000ohms)<\/p>\n\n\n\n<p>Ia = 0,00015A<\/p>\n\n\n\n<p>Pa = 100K*(18,3\/(100K+22K))*(18,3\/(100K+22K))<\/p>\n\n\n\n<p>Pa = 100E3*(18,3\/(100E3+22E3))*(18,3\/(100E3+22E3))<\/p>\n\n\n\n<p><strong>Pa = 0.00225 Watt<\/strong><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p>Ces formules s\u2019appliquent&nbsp;uniquement<strong>   <\/strong>   dans le cas o\u00f9 la sortie Vb ne d\u00e9livre pas de courant (cas d&rsquo;une entr\u00e9e d&rsquo;un convertisseur analogique-num\u00e9rique par exemple). Dans le cas o\u00f9 il y a justement un courant qui sort de ce pont, cela modifie la valeur de la tension de sortie. C\u2019est comme si vous rajoutiez une r\u00e9sistance en parall\u00e8le de la sortie. Cela a donc pour effet de donner un r\u00e9sistance Rb \u00e9quivalente plus faible et donc de changer la tension.<\/p>\n\n\n\n<p><a rel=\"noreferrer noopener\" href=\"http:\/\/www.sonelec-musique.com\/electronique_bases_diviseurs_res.html\" target=\"_blank\">Compl\u00e9ment d&rsquo;information\ufeff<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dans certaines situations, il faut r\u00e9duire la tension, car elle est trop \u00e9lev\u00e9e pour notre utilisation. La m\u00e9thode pr\u00e9sent\u00e9e ici consiste \u00e0 placer deux r\u00e9sistances en s\u00e9rie et de se relier aux bornes de la r\u00e9sistance relier au n\u00e9gatif de la pile. Les formules applicables dans cette situation sont V : Voltage, &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I : Courant [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/pages\/430"}],"collection":[{"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/comments?post=430"}],"version-history":[{"count":54,"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/pages\/430\/revisions"}],"predecessor-version":[{"id":1117,"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/pages\/430\/revisions\/1117"}],"wp:attachment":[{"href":"https:\/\/espacerm.com\/webgen\/wp-json\/wp\/v2\/media?parent=430"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}