{"id":219751,"date":"2025-05-26T18:33:55","date_gmt":"2025-05-26T18:33:55","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=219751"},"modified":"2025-05-26T18:33:57","modified_gmt":"2025-05-26T18:33:57","slug":"design-a-monostable-multivibrator-using-a-555-timer-a-capacitor-with-value-c-1-nf-and-appropriate-resistor-values-to-produce-an-output-pulse-of-20-%c2%b5s-duration","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/26\/design-a-monostable-multivibrator-using-a-555-timer-a-capacitor-with-value-c-1-nf-and-appropriate-resistor-values-to-produce-an-output-pulse-of-20-%c2%b5s-duration\/","title":{"rendered":"Design a monostable multivibrator using a 555 timer, a capacitor with value C = 1 nF and appropriate resistor values to produce an output pulse of 20 \u00b5s duration."},"content":{"rendered":"\n

Design a monostable multivibrator using a 555 timer, a capacitor with value C = 1 nF and appropriate resistor values to produce an output pulse of 20 \u00b5s duration.<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Monostable Multivibrator Design Using 555 Timer<\/strong><\/h3>\n\n\n\n

Given:<\/strong><\/p>\n\n\n\n

    \n
  • Pulse duration, T=20\u2009\u03bcsT = 20 \\, \\mu s<\/li>\n\n\n\n
  • Capacitance, C=1\u2009nF=1\u00d710\u22129\u2009FC = 1 \\, nF = 1 \\times 10^{-9} \\, F<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n

    1. Formula for Monostable Multivibrator Using 555 Timer:<\/strong><\/h3>\n\n\n\n

    The output pulse duration of a monostable 555 timer is given by: T=1.1\u00d7R\u00d7CT = 1.1 \\times R \\times C<\/p>\n\n\n\n

    Solving for RR: R=T1.1\u00d7CR = \\frac{T}{1.1 \\times C}<\/p>\n\n\n\n

    Substitute the given values: R=20\u00d710\u221261.1\u00d71\u00d710\u22129=20\u00d710\u221261.1\u00d710\u22129=18,181.8\u2009\u03a9R = \\frac{20 \\times 10^{-6}}{1.1 \\times 1 \\times 10^{-9}} = \\frac{20 \\times 10^{-6}}{1.1 \\times 10^{-9}} = 18,181.8 \\, \\Omega<\/p>\n\n\n\n

    So, use a resistor R\u224818.2\u2009k\u03a9R \\approx 18.2 \\, k\\Omega<\/strong> (standard E24 value).<\/p>\n\n\n\n

    \n\n\n\n

    2. Components Needed:<\/strong><\/h3>\n\n\n\n
      \n
    • 555 Timer IC<\/li>\n\n\n\n
    • Capacitor: 1 nF<\/li>\n\n\n\n
    • Resistor: 18.2 k\u03a9<\/li>\n\n\n\n
    • Trigger input (momentary switch or digital pulse)<\/li>\n\n\n\n
    • Power supply (typically 5V to 15V depending on the IC version)<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n

      3. Operation Explanation<\/strong><\/h3>\n\n\n\n

      A monostable multivibrator using a 555 timer produces a single output pulse of fixed duration in response to an external trigger. This configuration is commonly used in timing applications like pulse stretching, debouncing, or generating time delays.<\/p>\n\n\n\n

      In monostable mode, the 555 timer has one stable state\u2014LOW output<\/strong>. When a negative trigger pulse (voltage drops below 1\/3 Vcc) is applied to the TRIG<\/strong> pin (pin 2), the internal flip-flop of the 555 timer is set. This causes the output (pin 3)<\/strong> to go HIGH and initiates the charging of the external capacitor CC through the resistor RR.<\/p>\n\n\n\n

      The capacitor begins to charge exponentially through the resistor, and the timer monitors its voltage. When the voltage across the capacitor reaches 2\/3 Vcc<\/strong>, the internal comparator resets the flip-flop, causing the output to return LOW. The timing duration for which the output stays HIGH is determined by: T=1.1\u00d7R\u00d7CT = 1.1 \\times R \\times C<\/p>\n\n\n\n

      In this design, with C=1\u2009nFC = 1 \\, nF and R=18.2\u2009k\u03a9R = 18.2 \\, k\\Omega, the output remains HIGH for: T=1.1\u00d718.2\u00d7103\u00d71\u00d710\u22129\u224820\u2009\u03bcsT = 1.1 \\times 18.2 \\times 10^3 \\times 1 \\times 10^{-9} \\approx 20 \\, \\mu s<\/p>\n\n\n\n

      This provides a precise 20 \u00b5s pulse each time the circuit is triggered. After the pulse, the system resets and waits for the next trigger, making it ideal for generating consistent short-duration pulses in control circuits or signal processing.<\/p>\n\n\n\n

      \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

      Design a monostable multivibrator using a 555 timer, a capacitor with value C = 1 nF and appropriate resistor values to produce an output pulse of 20 \u00b5s duration. The Correct Answer and Explanation is: Monostable Multivibrator Design Using 555 Timer Given: 1. Formula for Monostable Multivibrator Using 555 Timer: The output pulse duration of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-219751","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219751","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=219751"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219751\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=219751"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=219751"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=219751"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}