{"id":7574,"date":"2024-09-21T16:28:33","date_gmt":"2024-09-21T16:28:33","guid":{"rendered":"https:\/\/ct1jqj.eu\/blog\/?p=7574"},"modified":"2024-09-21T23:38:35","modified_gmt":"2024-09-21T23:38:35","slug":"amplificador-de-audio-dc-servo-com-tda7293-pt-i","status":"publish","type":"post","link":"https:\/\/ct1jqj.eu\/?p=7574","title":{"rendered":"Amplificador de audio DC Servo Com TDA7293 (Pt. 1)"},"content":{"rendered":"<div class=\"pld-like-dislike-wrap pld-template-4\">\r\n    <div class=\"pld-like-wrap  pld-common-wrap\">\r\n    <a href=\"javascript:void(0)\" class=\"pld-like-trigger pld-like-dislike-trigger  \" title=\"\" data-post-id=\"7574\" data-trigger-type=\"like\" data-restriction=\"cookie\" data-already-liked=\"0\">\r\n                        <i class=\"far fa-smile\"><\/i>\r\n                    <\/a>\r\n    <span class=\"pld-like-count-wrap pld-count-wrap\">    <\/span>\r\n<\/div><div class=\"pld-dislike-wrap  pld-common-wrap\">\r\n    <a href=\"javascript:void(0)\" class=\"pld-dislike-trigger pld-like-dislike-trigger  \" title=\"\" data-post-id=\"7574\" data-trigger-type=\"dislike\" data-restriction=\"cookie\" data-already-liked=\"0\">\r\n                        <i class=\"far fa-frown\"><\/i>\r\n                    <\/a>\r\n    <span class=\"pld-dislike-count-wrap pld-count-wrap\"><\/span>\r\n<\/div><\/div><p style=\"text-align: justify;\">Ontem chegou-me este m\u00f3dulo amplificador, que segundo o an\u00fancio debita 2x100W. (Se alimentado com um transformador de 2x28W\/300W). Como se pode ver pelas fotografias, a placa est\u00e1 bem constru\u00edda e o dissipador tem umas dimens\u00f5es razo\u00e1veis para a pot\u00eancia debitada. Detalhe dos integrados em uso (TDA7293) e do rel\u00e9 de protec\u00e7\u00e3o.<\/p>\n\n\t\t<style>\n\t\t\t#gallery-1 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-1 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-1 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-1' class='gallery galleryid-7574 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7573'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.40.53-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7572'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.40.58-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7571'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.42.12-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p style=\"text-align: justify;\">N\u00e3o tendo para j\u00e1 um transformador com essa tens\u00e3o\/pot\u00eancia, decidi efectuar o teste com um transformador de 2x18V\/~125W, que dar\u00e1 uma tens\u00e3o DC ap\u00f3s rectificar e filtrar de \u00b125V, sendo que o m\u00e1ximo suportado, segundo o <em>datasheet<\/em> s\u00e3o \u00b150V. Coloquei um sinal sinusoidal de 1Khz e ajustei a amplitude do mesmo para 220mV (155mV RMS), que foi o m\u00e1ximo que atingiu antes de come\u00e7ar a distorcer. Com a carga usei uma resist\u00eancia de 4\u03a9\/100W por canal (E aqueceram bem apesar dos dissipadores) e obtive as medidas que se v\u00eaem na ultima fotografia:<\/p>\n\n\t\t<style>\n\t\t\t#gallery-2 {\n\t\t\t\tmargin: auto;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-item {\n\t\t\t\tfloat: left;\n\t\t\t\tmargin-top: 10px;\n\t\t\t\ttext-align: center;\n\t\t\t\twidth: 33%;\n\t\t\t}\n\t\t\t#gallery-2 img {\n\t\t\t\tborder: 2px solid #cfcfcf;\n\t\t\t}\n\t\t\t#gallery-2 .gallery-caption {\n\t\t\t\tmargin-left: 0;\n\t\t\t}\n\t\t\t\/* see gallery_shortcode() in wp-includes\/media.php *\/\n\t\t<\/style>\n\t\t<div id='gallery-2' class='gallery galleryid-7574 gallery-columns-3 gallery-size-thumbnail'><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7567'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.30.28-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7569'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.29.38-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><dl class='gallery-item'>\n\t\t\t<dt class='gallery-icon landscape'>\n\t\t\t\t<a href='https:\/\/ct1jqj.eu\/?attachment_id=7568'><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/ct1jqj.eu\/wp-content\/uploads\/2024\/09\/photo_2024-09-21-16.29.41-150x150.jpeg\" class=\"attachment-thumbnail size-thumbnail\" alt=\"\" \/><\/a>\n\t\t\t<\/dt><\/dl><br style=\"clear: both\" \/>\n\t\t<\/div>\n\n<p>Fazendo as contas e sendo que P=U\u00b2\/R, ent\u00e3o:<\/p>\n<p>Canal esquerdo: P=10,63\u00b274 = 28,24W<br \/>\nCanal direito: P=10,76\u00b2\/4 = 29.94W<\/p>\n<p style=\"text-align: justify;\">Como se pode ver, apesar de utilizar uma fonte de alimenta\u00e7\u00e3o inferior \u00e0 recomendada, obtive cerca de 30W, o que no geral, e uma vez que esta pot\u00eancia \u00e8 obtida antes de come\u00e7ar a distorcer, serve perfeitamente para utilizar numa sala de estar, mesmo que seja uma sala grande. Est\u00e1 longe dos 100W anunciados, mas segundo o <em>datasheet<\/em>, para obter 100W \u00e9 necess\u00e1rio uma tens\u00e3o de \u00b140V. E para essa pot\u00eancia, a distor\u00e7\u00e3o chega aos 10%, que n\u00e3o \u00e9 de todo agrad\u00e1vel! Quando tiver um transformador mais adequado, efectuarei novos testes.<\/p>\n<p>73&#8217;s<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ontem chegou-me este m\u00f3dulo amplificador, que segundo o an\u00fancio debita 2x100W. (Se alimentado com um transformador de 2x28W\/300W). Como se pode ver pelas fotografias, a placa est\u00e1 bem constru\u00edda e o dissipador tem umas dimens\u00f5es razo\u00e1veis para a pot\u00eancia debitada. Detalhe dos integrados em uso (TDA7293) e do rel\u00e9 de protec\u00e7\u00e3o. N\u00e3o tendo para j\u00e1 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":7573,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,5,6],"tags":[66,88,365],"class_list":["post-7574","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-audio","category-electronica","category-equipamento","tag-amplificador","tag-audio","tag-tda7293"],"_links":{"self":[{"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/posts\/7574","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7574"}],"version-history":[{"count":5,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/posts\/7574\/revisions"}],"predecessor-version":[{"id":7580,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/posts\/7574\/revisions\/7580"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=\/wp\/v2\/media\/7573"}],"wp:attachment":[{"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7574"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7574"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ct1jqj.eu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7574"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}