{"id":398,"date":"2015-08-08T14:18:00","date_gmt":"2015-08-08T14:18:00","guid":{"rendered":"http:\/\/machineryequipmentonline.com\/video-equipment\/uncategorized\/ramp-generators\/"},"modified":"2015-08-08T14:18:00","modified_gmt":"2015-08-08T14:18:00","slug":"ramp-generators","status":"publish","type":"post","link":"http:\/\/machineryequipmentonline.com\/video-equipment\/ramp-generators\/","title":{"rendered":"RAMP GENERATORS."},"content":{"rendered":"<div class=\"rvfrd6a0dc85bbc3fc\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '61e5902552e2353963d8d2f1bd1f4a8f',\n\t\t'format' : 'iframe',\n\t\t'height' : 250,\n\t\t'width' : 300,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/61e5902552e2353963d8d2f1bd1f4a8f\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.rvfrd6a0dc85bbc3fc {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.rvfrd6a0dc85bbc3fc {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.rvfrd6a0dc85bbc3fc {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.rvfrd6a0dc85bbc3fc {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.rvfrd6a0dc85bbc3fc {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<h3 align=\"justify\"><em><u>RAMP GENERATORS<\/u><\/em><\/h3>\n<p align=\"justify\">The sawtooth drive waveform required by a \ufb01eld timebase is called a ramp, and of several possible methods of generating it, the simplest is to use a series RC charging circuit. Fig. 10.1 shows the principle, in which capacitor C is allowed to charge towards HT potential via series resistor R. Each time the switch across the capacitor is closed the capacitor rapidly discharges to form the \ufb02yback stroke of the scanning spot. As the waveform in Fig. 10.1 shows, however, the saw- tooth\u2019s forward stroke is not linear. As the capacitor charges the volt- age across the resistor diminishes, with a corresponding reduction of current. In this series circuit the reducing resistor current \ufb02ows also into the capacitor, and this diminution of charging current with time is responsible for the curvature in the waveform. It can be overcome by charging the capacitor from a <i>constant-cur<\/i><i>r<\/i><i>en<\/i><i>t source<\/i>. In its simplest form this may consist of a very high HT potential and very large resistor R; provided the charging process has not advanced far towards VHT before the \ufb02yback switch closes the charging current is substantially constant, and the resulting ramp substantially linear. This con\ufb01guration is inconvenient for modern IC circuit design, where a constant-current generator is easily arranged in the emitter circuit of an internal transistor. <\/p>\n<p align=\"justify\">\n<p align=\"justify\"><i><\/i> <\/p><div class=\"nanas6a0dc85bbc508\" ><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-0778475562755157\"\n     crossorigin=\"anonymous\"><\/script>\n<!-- 300x600 television-and-video -->\n<ins class=\"adsbygoogle\"\n     style=\"display:inline-block;width:300px;height:600px\"\n     data-ad-client=\"ca-pub-0778475562755157\"\n     data-ad-slot=\"6549443290\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.nanas6a0dc85bbc508 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.nanas6a0dc85bbc508 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.nanas6a0dc85bbc508 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.nanas6a0dc85bbc508 {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.nanas6a0dc85bbc508 {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n<div class=\"kfxpa6a0dc85bbc48d\" ><script type=\"text\/javascript\">\n\tatOptions = {\n\t\t'key' : '0c1eb4c533eaedb7b996f49a5a4983a9',\n\t\t'format' : 'iframe',\n\t\t'height' : 300,\n\t\t'width' : 160,\n\t\t'params' : {}\n\t};\n<\/script>\n<script type=\"text\/javascript\" src=\"\/\/www.highperformanceformat.com\/0c1eb4c533eaedb7b996f49a5a4983a9\/invoke.js\"><\/script><\/div><style type=\"text\/css\">\r\n@media screen and (min-width: 1201px) {\r\n.kfxpa6a0dc85bbc48d {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 993px) and (max-width: 1200px) {\r\n.kfxpa6a0dc85bbc48d {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 769px) and (max-width: 992px) {\r\n.kfxpa6a0dc85bbc48d {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (min-width: 768px) and (max-width: 768px) {\r\n.kfxpa6a0dc85bbc48d {\r\ndisplay: block;\r\n}\r\n}\r\n@media screen and (max-width: 767px) {\r\n.kfxpa6a0dc85bbc48d {\r\ndisplay: block;\r\n}\r\n}\r\n<\/style>\r\n\n<p align=\"justify\"><a href=\"http:\/\/lh3.googleusercontent.com\/-TUR9-5J9ANg\/VcYPqwY5uMI\/AAAAAAAB08c\/Z9n5CxnIOgE\/s1600-h\/TIMEBASE%252520CIRCUITS-0128%25255B5%25255D.jpg\"><img decoding=\"async\" loading=\"lazy\" style=\"background-image: none; border-bottom: 0px; border-left: 0px; margin: 0px auto; padding-left: 0px; padding-right: 0px; display: block; float: none; border-top: 0px; border-right: 0px; padding-top: 0px\" title=\"TIMEBASE CIRCUITS-0128\" border=\"0\" alt=\"TIMEBASE CIRCUITS-0128\" src=\"http:\/\/lh3.googleusercontent.com\/-NXcu23IxopQ\/VcYPssHz7VI\/AAAAAAAB08k\/nPXEsG4gwn8\/TIMEBASE%252520CIRCUITS-0128_thumb%25255B1%25255D.jpg?imgmax=800\" width=\"244\" height=\"101\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>RAMP GENERATORS The sawtooth drive waveform required by a \ufb01eld timebase is called a ramp, and of several possible methods of generating it, the simplest is to use a series RC charging circuit. Fig. 10.1 shows the principle, in which capacitor C is allowed to charge towards HT potential via series resistor R. Each time [&hellip;]<br \/><a href=\"http:\/\/machineryequipmentonline.com\/video-equipment\/ramp-generators\/\" class=\"more-link\" >Continue reading&#8230;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"aioseo_notices":[],"views":559,"_links":{"self":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/398"}],"collection":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/comments?post=398"}],"version-history":[{"count":0,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/posts\/398\/revisions"}],"wp:attachment":[{"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/media?parent=398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/categories?post=398"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/machineryequipmentonline.com\/video-equipment\/wp-json\/wp\/v2\/tags?post=398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}