{"id":1940,"date":"2017-01-31T11:38:16","date_gmt":"2017-01-31T14:38:16","guid":{"rendered":"http:\/\/blog.generaleccentric.net\/?p=1940"},"modified":"2017-01-31T11:42:34","modified_gmt":"2017-01-31T14:42:34","slug":"more-experiments-in-servo-actuated-frequency-displays","status":"publish","type":"post","link":"https:\/\/blog.generaleccentric.net\/?p=1940","title":{"rendered":"More Experiments in Servo-actuated Frequency Displays"},"content":{"rendered":"<h4>January 23, 2017<\/h4>\n<div><\/div>\n<div>Using the circuit from\u00a0<a href=\"http:\/\/www.epanorama.net\/circuits\/servo10v.html\">Servo controlling circuit<\/a>, I breadboarded this:<\/div>\n<div>\n<figure id=\"attachment_1941\" aria-describedby=\"caption-attachment-1941\" style=\"width: 2000px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615.png\" rel=\"lightbox[1940]\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1941 size-full\" src=\"http:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615.png\" width=\"2000\" height=\"863\" srcset=\"https:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615.png 2000w, https:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615-300x129.png 300w, https:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615-768x331.png 768w, https:\/\/blog.generaleccentric.net\/wp-content\/uploads\/2017\/01\/Evernote-Snapshot-20170126-101615-1024x442.png 1024w\" sizes=\"auto, (max-width: 2000px) 100vw, 2000px\" \/><\/a><figcaption id=\"caption-attachment-1941\" class=\"wp-caption-text\">555 servo control using variable voltage<\/figcaption><\/figure>\n<\/div>\n<div><\/div>\n<div>Results in a clean PWM pulse train, however:<\/div>\n<ul>\n<li>with pin 7 on the 555 biased to 1.47v, travel is less than 90 degrees between inputs of .7 \u00a0and 5 v.<\/li>\n<\/ul>\n<hr \/>\n<h4>January 26, 2017<\/h4>\n<div><\/div>\n<div>Adjusted circuit:<\/div>\n<ul>\n<li>the input current determines the rotational\u00a0range of the servo, so we need to place a trimmer pot there<\/li>\n<li>waveform is clean and pulses are spaced at\u00a0a consistent 22ms apart<iframe loading=\"lazy\" title=\"Experiment: Servo control using 555\" width=\"474\" height=\"267\" src=\"https:\/\/www.youtube.com\/embed\/8T4FNR10-CY?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/li>\n<\/ul>\n<div>\n<hr \/>\n<\/div>\n<h4>January 27, 2017<\/h4>\n<div>\n<ul>\n<li>tested circuit on my WBR Regen 31m receiver: results are\u00a0difficult to repeat with any consistency.<\/li>\n<li>circuit loading on radio changes calibration\u2014this would make it difficult to use with different radios<\/li>\n<li>loading also affects tuning<\/li>\n<li>On the positive side, circuit continues to outperform op-amp and Arduino\u00a0circuits, with no problems of power supply dropouts<\/li>\n<\/ul>\n<\/div>\n<hr \/>\n<h3>Conclusion<\/h3>\n<div>I think that it&#8217;s time to go back to the Arduino-controlled circuit to see if I can wrangle the power-dropout-reset issue.<\/p>\n<hr \/>\n<\/div>\n<div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>January 23, 2017 Using the circuit from\u00a0Servo controlling circuit, I breadboarded this: Results in a clean PWM pulse train, however: with pin 7 on the 555 biased to 1.47v, travel is less than 90 degrees between inputs of .7 \u00a0and 5 v. January 26, 2017 Adjusted circuit: the input current determines the rotational\u00a0range of the &hellip; <a href=\"https:\/\/blog.generaleccentric.net\/?p=1940\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">More Experiments in Servo-actuated Frequency Displays<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_links_to":"","_links_to_target":"","footnotes":""},"categories":[97,22,110],"tags":[],"class_list":["post-1940","post","type-post","status-publish","format-standard","hentry","category-amateur_radio","category-electronics","category-radio"],"_links":{"self":[{"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/posts\/1940","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1940"}],"version-history":[{"count":8,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/posts\/1940\/revisions"}],"predecessor-version":[{"id":1949,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=\/wp\/v2\/posts\/1940\/revisions\/1949"}],"wp:attachment":[{"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1940"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1940"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.generaleccentric.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1940"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}