{"id":64458,"date":"2025-05-12T09:38:58","date_gmt":"2025-05-12T06:38:58","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=64458"},"modified":"2025-05-12T09:38:58","modified_gmt":"2025-05-12T06:38:58","slug":"ne555-astable-circuit","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/engineering\/ne555-astable-circuit\/","title":{"rendered":"NE555 Timer Astable Circuit Calculator"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 class=\"text-lg font-display font-bold\">Astable Oscillator Timing Values for NE555<\/h2><\/div><div class=\"relative group inline-block\">\n  <button class=\"favorite\" id=\"favorite\" data-favorite-id=\"64458\" data-favorite-title=\"NE555 Timer Astable Circuit\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/engineering\/ne555-astable-circuit\/\" data-favorite-excerpt=\"This calculator helps design an astable multivibrator circuit using the NE555 timer IC by calculating the output frequency, time period, and duty cycle from resistor and capacitor values. It\u2019s ideal for creating clocks, blinkers, tone generators, and pulse-width modulated signals.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-electrical\">\n    <span class=\"icon icon-shape-star-empty\"><\/span>\n  <\/button>\n  <div class=\"absolute right-full -translate-y-1\/2 top-1\/2 mr-2 w-max max-w-xs px-3 py-2 bg-gray-800 text-white text-xs rounded shadow-lg opacity-0 group-hover:opacity-100 transition-opacity duration-200 z-10 pointer-events-none\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/en\/engineering\/ne555-astable-circuit\/\" method=\"POST\" class=\"calculator\" id=\"calculator-64458\" data-post=\"64458\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field has-term\" id=\"input-1\"><label for=\"field-1\">Resistor 1<\/label><div class=\"term\">R\u2081<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"resistor_1\" id=\"field-1\" min=\"0.1\" step=\"any\" value=\"1000\"\/><div class=\"unit\">\u03a9<\/div><small>Resistor between Vcc and discharge pin<\/small><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-2\">Resistor 2<\/label><div class=\"term\">R\u2082<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"resistor_2\" id=\"field-2\" min=\"0.1\" step=\"any\" value=\"1000\"\/><div class=\"unit\">\u03a9<\/div><small>Resistor between discharge and threshold pin<\/small><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-3\">Capacitor C<\/label><div class=\"term\">C<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"capacitor_c\" id=\"field-3\" min=\"1.0E-6\" step=\"any\" value=\"1\"\/><div class=\"unit\">\u00b5F<\/div><small>Capacitor connected between threshold and ground<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"64458\">Calculate<\/button><button type=\"reset\">Reset<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculate automatically<\/label><small>If enabled, the result will update automatically when you change any value.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Your Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>High Time<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"ms\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-2\"><span class=\"field-title\"><span>Low Time<\/span><\/span><span class=\"field-value\" id=\"result-2\" data-unit=\"ms\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-3\"><span class=\"field-title\"><span>Total Period<\/span><\/span><span class=\"field-value\" id=\"result-3\" data-unit=\"ms\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-4\"><span class=\"field-title\"><span>Frequency<\/span><\/span><span class=\"field-value\" id=\"result-4\" data-unit=\"Hz\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-5\"><span class=\"field-title\"><span>Duty Cycle<\/span><\/span><span class=\"field-value\" id=\"result-5\" data-unit=\"%\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Leave a Comment<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"64458\" aria-live=\"polite\"><h2 class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/h2><div class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/span><\/button><button class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/span><\/button><button class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/span><\/button><button class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/span><\/button><button class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\">\u274c <\/span><span class=\"reaction-description font-medium\">Inaccurate <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><ins class=\"adsbygoogle\"\n     style=\"display:block; text-align:center; margin: 32px 0;\"\n     data-ad-layout=\"in-article\"\n     data-ad-format=\"fluid\"\n     data-ad-client=\"ca-pub-1721569815777345\"\n     data-ad-slot=\"6317458308\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script>\n<p><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>NE555 Astable Circuit Formulas<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n$$T = 0.693 \\cdot (R_1 + 2R_2) \\cdot C$$\n$$f = \\frac{1}{T} = \\frac{1.44}{(R_1 + 2R_2) \\cdot C}$$\n$$\\text{Duty Cycle} (\\%) = \\frac{R_1 + R_2}{R_1 + 2R_2} \\cdot 100$$\n<\/div>\r\n\t<\/figure>\r\n\t<br \/>\n<strong>Where:<\/strong><\/p>\n<ul>\n<li>$$T$$ = period (seconds)  <\/li>\n<li>$$f$$ = frequency (Hz)  <\/li>\n<li>$$R_1$$ = resistor from Vcc to discharge (\u03a9)  <\/li>\n<li>$$R_2$$ = resistor from discharge to threshold (\u03a9)  <\/li>\n<li>$$C$$ = timing capacitor (F)<\/li>\n<\/ul>\n<p>These formulas are standard for configuring the NE555 timer in astable mode.<br \/>\r\n<\/section><br \/>\n<section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>NE555 Timer Astable Circuit \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<p>\n<strong>Given:<\/strong><\/p>\n<ul>\n<li>$$R_1$$ = 1 k\u03a9  <\/li>\n<li>$$R_2$$ = 3.3 k\u03a9  <\/li>\n<li>$$C$$ = 10 \u00b5F = 0.00001 F<\/li>\n<\/ul>\n<p><strong>Calculation:<\/strong><\/p>\n<ol>\n<li>$$T = 0.693 \\cdot (1000 + 2 \\cdot 3300) \\cdot 0.00001 = 0.693 \\cdot 7600 \\cdot 0.00001 \u2248 0.0527~s$$<\/li>\n<li>$$f = \\frac{1}{0.0527} \u2248 18.97~Hz$$<\/li>\n<li>$$\\text{Duty Cycle} = \\frac{1000 + 3300}{1000 + 6600} \\cdot 100 = \\frac{4300}{7600} \\cdot 100 \u2248 56.6\\%$$<\/li>\n<\/ol>\n<p>\n\r\n<\/section><br \/>\nThe NE555 timer is a highly stable IC for generating precise timing pulses. In astable mode, it oscillates continuously, making it perfect for applications like LED blinkers, tone generation, PWM control, and clocks. This calculator helps determine output characteristics based on resistor and capacitor values, enabling fast and accurate prototyping of oscillator circuits.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This calculator helps design an astable multivibrator circuit using the NE555 timer IC by calculating the output frequency, time period, and duty cycle from resistor and capacitor values. It\u2019s ideal for creating clocks, blinkers, tone generators, and pulse-width modulated signals.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4],"tags":[21],"class_list":["post-64458","post","type-post","status-publish","format-standard","hentry","category-engineering","tag-electrical"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/users\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=64458"}],"version-history":[{"count":2,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64458\/revisions"}],"predecessor-version":[{"id":64460,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/64458\/revisions\/64460"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=64458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=64458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=64458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}