{"id":18697,"date":"2024-11-22T09:16:00","date_gmt":"2024-11-22T03:46:00","guid":{"rendered":"https:\/\/www.electronicsforu.com\/?p=18697"},"modified":"2024-12-05T14:25:53","modified_gmt":"2024-12-05T08:55:53","slug":"lpg-leakage-detector-low-cost","status":"publish","type":"post","link":"https:\/\/www.electronicsforu.com\/electronics-projects\/lpg-leakage-detector-low-cost","title":{"rendered":"Low-Cost LPG Leakage Detector Without a Microcontroller"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2017\/06\/scdnew-150x150.jpg\" alt=\"EFY Tested LPG Leakage Detector\" class=\"wp-image-36667\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2017\/06\/scdnew-150x150.jpg 150w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2017\/06\/scdnew.jpg 308w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure><\/div>\n\n\n<p>While LPG leakage detectors are widely available, they are often costly and rely on <a href=\"https:\/\/www.electronicsforu.com\/microcontroller-projects-ideas\" target=\"_blank\" rel=\"noopener\">microcontroller<\/a>-based designs. Here, we present an affordable, easy-to-build LPG leakage detector that eliminates the need for expensive components.&nbsp;<\/p>\n\n\n\n<p>The primary function of this circuit is to detect LPG leaks efficiently. Figure 1 showcases the author\u2019s working prototype.<\/p>\n\n\n<div class=\"wp-block-image wp-image-18698 size-full\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1080\" height=\"464\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6.jpg\" alt=\"LPG leakage detector prototype\" class=\"wp-image-18698\" style=\"width:571px;height:auto\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6.jpg 1080w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6-800x344.jpg 800w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6-696x299.jpg 696w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6-1068x459.jpg 1068w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-1-6-977x420.jpg 977w\" sizes=\"auto, (max-width: 1080px) 100vw, 1080px\" \/><figcaption class=\"wp-element-caption\">Fig. 1: Author\u2019s prototype of LPG Leakage Detector<\/figcaption><\/figure><\/div>\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Contents<\/h2><nav><ul><li><a href=\"#required-components\">Required Components<\/a><\/li><li><a href=\"#circuit-and-working-of-the-lpg-leakage-detector\">Circuit and Working of the LPG Leakage Detector<\/a><\/li><li><a href=\"#construction-placement-and-testing-of-the-detector\">LPG Leakage Detector PCB Design<\/a><\/li><li><a href=\"#testing\">Testing LPG Leakage Detector<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"required-components\"><strong>Required Components<\/strong><\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"547\" height=\"720\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/parts-list-1.jpg\" alt=\"Components required for LPG Leakage Detector\" class=\"wp-image-18702\" style=\"width:255px;height:auto\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/parts-list-1.jpg 547w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/parts-list-1-608x800.jpg 608w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/parts-list-1-319x420.jpg 319w\" sizes=\"auto, (max-width: 547px) 100vw, 547px\" \/><\/figure><\/div>\n\n\n<h2 class=\"wp-block-heading\" id=\"circuit-and-working-of-the-lpg-leakage-detector\"><strong>Circuit and Working of the LPG Leakage Detector<\/strong><\/h2>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"636\" height=\"375\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/test-points.jpg\" alt=\"test points\" class=\"wp-image-18703\" style=\"width:332px;height:auto\"\/><\/figure><\/div>\n\n<div class=\"wp-block-image wp-image-18699 size-full\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1080\" height=\"535\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6.jpg\" alt=\"LPG Leakage Detector Circuit Diagram\" class=\"wp-image-18699\" style=\"width:571px;height:auto\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6.jpg 1080w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6-800x397.jpg 800w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6-324x160.jpg 324w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6-696x345.jpg 696w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6-1068x530.jpg 1068w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-2-6-847x420.jpg 847w\" sizes=\"auto, (max-width: 1080px) 100vw, 1080px\" \/><figcaption class=\"wp-element-caption\">Fig. 2: Circuit diagram of the LPG detector<\/figcaption><\/figure><\/div>\n\n\n<p>Circuit diagram of the low-cost LPG detector is shown in Fig. 2. It is built around step-down transformer X1, two rectifier diodes <a href=\"https:\/\/www.diodes.com\/assets\/Datasheets\/ds28002.pdf\" target=\"_blank\" rel=\"noopener\">1N4007<\/a> (D1 and D2), a 1000\u00b5F capacitor (C1), <a href=\"https:\/\/www.electronicsforu.com\/resources\/learn-electronics\/7805-ic-voltage-regulator\" target=\"_blank\" rel=\"noopener\">7805<\/a> voltage regulator (IC1), MQ-6 LPG gas sensor (GS1), dual comparator LM393 (IC2), darlington transistor TIP122 (T2), 12V high-gain siren\/buzzer (PZ1) and a few other components.<\/p>\n\n\n\n<p>The mains supply is reduced by transformer X1, rectified by diodes D1 and D2 in a <a href=\"https:\/\/www.electronicsforu.com\/resources\/learn-electronics\/half-full-wave-rectifier-basics\" target=\"_blank\" rel=\"noopener\">full-wave rectifier<\/a> configuration, filtered by capacitor C1, and stabilized at 5V DC by voltage regulator 7805 (IC1), supplying the necessary power to the circuit<\/p>\n\n\n\n<p>At the heart of the circuit is dual comparator IC LM393 (IC2). It is used to compare two different voltages, namely, reference voltage and MQ-6 gas sensor output voltage.<\/p>\n\n\n\n<p>Reference voltage at non-inverting pin 3 of IC2 is set using potentiometer VR1 to adjust voltage levels based on sensitivity requirements. LPG sensor (MQ-6) output voltage is fed to inverting pin 2 of IC2.<\/p>\n\n\n\n<p>When the reference voltage at pin 3 of IC2 is lower than the sensor voltage at pin 2, the output goes low, indicating no LPG leakage. With low output, T1 remains cut-off and there is no current flow through the buzzer; it does not sound and remains in silence mode.<\/p>\n\n\n\n<p>If reference voltage is greater than sensor voltage, output goes high, which means there is LPG leakage. The high output switches on transistor T1 and the buzzer rings loudly to alert the people around.<\/p>\n\n\n\n<p>Detecting gas leaks becomes effortless with this circuit, as it leverages inexpensive components and offers adjustable sensitivity using the VR1 potentiometer to suit various environments.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"construction-placement-and-testing-of-the-detector\"><strong>LPG Leakage Detector PCB Design<\/strong><\/h2>\n\n\n\n<p>An PCB pattern of the LPG leakage detector is shown in Fig. 3 and its component layout in Fig. 4.<\/p>\n\n\n<div class=\"wp-block-image wp-image-18700\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"957\" height=\"590\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5.jpg\" alt=\"PCB pattern of the LPG leakage detector\" class=\"wp-image-18700\" style=\"width:495px;height:auto\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5.jpg 957w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5-800x493.jpg 800w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5-356x220.jpg 356w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5-696x429.jpg 696w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-3-5-681x420.jpg 681w\" sizes=\"auto, (max-width: 957px) 100vw, 957px\" \/><figcaption class=\"wp-element-caption\">Fig. 3: PCB pattern of the LPG leakage detector<\/figcaption><\/figure><\/div>\n\n<div class=\"wp-block-image wp-image-18701\">\n<figure class=\"aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"957\" height=\"587\" src=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-4-3.jpg\" alt=\"Component layout of the PCB for LPG gas leakage detector\" class=\"wp-image-18701\" style=\"width:495px;height:auto\" srcset=\"https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-4-3.jpg 957w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-4-3-800x491.jpg 800w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-4-3-696x427.jpg 696w, https:\/\/www.electronicsforu.com\/wp-contents\/uploads\/2016\/05\/Fig-4-3-685x420.jpg 685w\" sizes=\"auto, (max-width: 957px) 100vw, 957px\" \/><figcaption class=\"wp-element-caption\">Fig. 4: Component layout of the PCB<\/figcaption><\/figure><\/div>\n\n\n<p><strong>Download PCB and component layout PDFs:<\/strong> <a href=\"\/\/electronicsforu.com\/wp-contents\/uploads\/2016\/05\/lowcostlpgdetector.zip\">click here<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"testing\"><strong>Testing LPG Leakage Detector<\/strong><\/h2>\n\n\n\n<p>After assembling the circuit on a PCB, enclose it in a box with an opening for the gas to enter. Place the unit near the LPG cylinder or gas stove, within a distance of one meter. Vary preset VR1 to adjust sensitivity of the sensor.<\/p>\n\n\n\n<p>Verify the voltages are as per test points table before using the circuit. Now, spray the gas from the bottle (as shown on the left side of author\u2019s prototype) towards MQ-6 gas sensor and measure voltage at TP3; it should be high.<\/p>\n\n\n\n<p>If you do not have a gas-filled bottle, place the LPG leakage detector&nbsp;near the gas stove burner and turn it on for a few seconds without igniting. Then, turn the burner off and adjust VR1 until buzzer sounds.<\/p>\n\n\n\n<p><strong>Check other related Projects:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.electronicsforu.com\/electronics-projects\/lpg-gas-leakage-detection\">LPG Gas Leakage Detection using Arduino<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.electronicsforu.com\/electronics-projects\/hardware-diy\/gas-leakage-alarm\">Gas Leakage Alarm<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.electronicsforu.com\/electronics-projects\/hardware-diy\/smoke-alcohol-lpg-detection-alarm\">Smoke, Alcohol and LPG-Detection Alarm<\/a><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><em>Pamarthi Kanakaraja is associate professor (R&amp;D cell) in Usharama College of Engineering and Technology, Andhra Pradesh. He has been working in the field of embedded designing and programming concepts for the last six years.<\/em><\/p>\n\n\n\n<p>This article was first published on 5 September 2016 and recently updated in October 2024.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>While LPG leakage detectors are widely available, they are often costly and rely on microcontroller-based designs. Here, we present an affordable, easy-to-build LPG leakage detector that eliminates the need for expensive components.&nbsp; The primary function of this circuit is to detect LPG leaks efficiently. Figure 1 showcases the author\u2019s working prototype. Required Components Circuit and [&hellip;]<\/p>\n","protected":false},"author":13,"featured_media":18698,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,23,6071],"tags":[130,114,111,110,11087,113],"class_list":{"0":"post-18697","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-electronics-projects","8":"category-hardware-diy","9":"category-intermediate-projects","10":"tag-digital-electronics-projects","11":"tag-ece-projects","12":"tag-electrical-projects","13":"tag-electronics-projects","14":"tag-jan-2016","15":"tag-mini-projects"},"_links":{"self":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts\/18697","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/comments?post=18697"}],"version-history":[{"count":2,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts\/18697\/revisions"}],"predecessor-version":[{"id":153722,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/posts\/18697\/revisions\/153722"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/media\/18698"}],"wp:attachment":[{"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/media?parent=18697"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/categories?post=18697"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.electronicsforu.com\/wp-json\/wp\/v2\/tags?post=18697"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}