{"id":18813,"date":"2026-10-10T17:05:14","date_gmt":"2026-10-10T09:05:14","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/"},"modified":"2026-10-10T17:05:14","modified_gmt":"2026-10-10T09:05:14","slug":"power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/","title":{"rendered":"Power Supply Ripple Measurement: Match Bandwidth, Probe Loop and Output Loading First"},"content":{"rendered":"<p class=\"quick-answer\">Power supply ripple measurement is comparable only when the measurement conditions are comparable. Before judging a trace against a datasheet value, document bandwidth, the probe\/reference arrangement, added termination components, output loading and the measurement location. A convincing screenshot with an undocumented setup is not an acceptance result.<\/p>\n<figure><img loading decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/01-application-a-3.png?quality=85&strip=all\" alt=\"Power Supply Ripple Measurement: Match Bandwidth, Probe Loop and Output Loading First  title=\" width=\"1536\" height=\"1024\" power supply ripple measurement: match probe loop and output first title =\"\"><figcaption>Rejected native bottle-capping control-panel correction candidate. Its exposed serial marking remains unverifiable against the authentic source. It is not an approved application image, a performed ripple test or a selected rating for an unknown machine load.<\/figcaption><\/figure>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u03a0\u03af\u03bd\u03b1\u03ba\u03b1\u03c2 \u03c0\u03b5\u03c1\u03b9\u03b5\u03c7\u03bf\u03bc\u03ad\u03bd\u03c9\u03bd<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">\u039c\u03c0\u03b1\u03c1\u03ad\u03c4\u03b1<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Read_the_note_that_defines_the_number\" >Read the note that defines the number<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Separate_three_observations_before_diagnosing_a_supply\" >Separate three observations before diagnosing a supply<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#A_useful_measurement_record\" >A useful measurement record<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Do_not_make_two_different_methods_look_identical\" >Do not make two different methods look identical<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#The_application_photo_should_not_invent_a_test_result\" >The application photo should not invent a test result<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#What_to_ask_when_acceptance_evidence_is_incomplete\" >What to ask when acceptance evidence is incomplete<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Frequently_asked_questions\" >Frequently asked questions<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Does_150mV_peak-to-peak_mean_every_oscilloscope_view_must_show_that_or_less\" >Does 150mV peak-to-peak mean every oscilloscope view must show that or less?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Can_an_article_image_prove_the_supply_passed_the_test\" >Can an article image prove the supply passed the test?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Does_the_approved_PDF_contain_the_complete_probe_note\" >Does the approved PDF contain the complete probe note?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.wehopower.com\/el\/news\/power-supply-ripple-measurement-match-bandwidth-probe-loop-and-output-loading-first\/#Sources_and_revision_boundary\" >Sources and revision boundary<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Read_the_note_that_defines_the_number\"><\/span>Read the note that defines the number<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The WEHO MDR-20 English product page lists 150mV peak-to-peak for the 24V model. Its ripple note specifies a 20MHz bandwidth, a 12-inch twisted pair and parallel 0.1\u00b5F and 47\u00b5F capacitors. The general measurement note identifies 230VAC input, rated load and 25\u00b0C ambient unless otherwise stated. Those conditions belong with the table entry; deleting them changes what the comparison means.<\/p>\n<p>The authentic MDR-20-24 photographs and approved sheet agree on a 24V1.0A nominal output. The full-model identification is on the real right-side plate, not a large invented front label. A procurement record should retain both the actual unit identity and the document note used for the test comparison.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Separate_three_observations_before_diagnosing_a_supply\"><\/span>Separate three observations before diagnosing a supply<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A source-output observation, a sensor-end observation and a probe setup\u2019s own pickup do not answer the same question. A field measurement at a distant terminal includes the wiring and connected equipment context. It should not automatically be called the supply\u2019s datasheet ripple measurement.<\/p>\n<p>First decide whether the task is to reproduce the manufacturer\u2019s specified method or to investigate the actual load\u2019s voltage quality. Both may be useful, but they need separately identified locations and conditions. Record which observation is being discussed before assigning a cause or changing the product.<\/p>\n<figure><img loading decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/04-engineering-context-7.png?quality=85&strip=all\" alt=\"Power Supply Ripple Measurement: Match Bandwidth, Probe Loop and Output Loading First  title=\" width=\"1536\" height=\"1024\" power supply ripple measurement: match probe loop and output first title =\"\"><figcaption>Source-note evidence map, not a probe wiring instruction or a simulated oscilloscope trace. The 150mV peak-to-peak value is a table limit, not a measured result.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"A_useful_measurement_record\"><\/span>A useful measurement record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<table>\n<thead>\n<tr>\n<th>Item to record<\/th>\n<th>Question it answers<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Full model\/revision and source note<\/td>\n<td>Which actual product and specified method are being compared?<\/td>\n<\/tr>\n<tr>\n<td>Input, output load and ambient<\/td>\n<td>Were conditions comparable to the adopted note?<\/td>\n<\/tr>\n<tr>\n<td>Measurement location<\/td>\n<td>Was the observation at the supply or at the equipment load?<\/td>\n<\/tr>\n<tr>\n<td>Instrument bandwidth and channel setup<\/td>\n<td>What observation range and signal handling were used?<\/td>\n<\/tr>\n<tr>\n<td>Probe\/reference connection and lead routing<\/td>\n<td>What was the actual measurement loop and pickup context?<\/td>\n<\/tr>\n<tr>\n<td>Termination network<\/td>\n<td>Were the cited added components present and documented?<\/td>\n<\/tr>\n<tr>\n<td>Trace scale, interval and repeat observations<\/td>\n<td>Can the image be interpreted and reproduced?<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Have qualified personnel establish the safe instrument and reference arrangement. This guide does not direct connection of an ordinary grounded probe to mains or an unknown node, and it is not authorization to open an energized supply. Follow equipment and instrument instructions; a photograph of a control panel cannot establish a safe probing point.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Do_not_make_two_different_methods_look_identical\"><\/span>Do not make two different methods look identical<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>If the local method does not reproduce the page\u2019s bandwidth or network, retain the actual setup and state the difference. A value recorded under another method may be useful diagnostic evidence, but it should not silently be relabeled as a passing manufacturer-condition result.<\/p>\n<p>Likewise, keep a peak-to-peak result distinct from a different statistical or frequency-domain quantity. Record the observation interval and state being measured rather than reducing a changing installation to a single context-free number. Avoid claiming that a capacitor added for a measurement proves the same behavior at every remote load in the machine.<\/p>\n<figure><img loading decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/02-application-b-3.png?quality=85&strip=all\" alt=\"Power Supply Ripple Measurement: Match Bandwidth, Probe Loop and Output Loading First  title=\" width=\"1536\" height=\"1024\" power supply ripple measurement: match probe loop and output first title =\"\"><figcaption>Rejected native auxiliary-control correction candidate beside a screw-driving assembly fixture. The exposed side-label frequency and serial text have not passed source-exact review; this image is not release-ready.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"The_application_photo_should_not_invent_a_test_result\"><\/span>The application photo should not invent a test result<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The MDR-20-24 is 22.5mm across its narrow front,90mm high and 100mm from front to rear. Its drawing shows the rear DIN-rail arrangement. Circular front openings provide screw access; rectangular end-face openings are the conductor entries. Routing a wire into the front screw access or a blue ventilation slot would be a wrong installation, regardless of whether the model label looked correct.<\/p>\n<p>The two scenes here depict protected dry control compartments and source-supported rear-rail relationships. They do not show live probing, a fabricated waveform, a calibration certificate or proof that a particular machine passed EMC. Exact controller and sensor compatibility must be confirmed from their own documentation.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_to_ask_when_acceptance_evidence_is_incomplete\"><\/span>What to ask when acceptance evidence is incomplete<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Ask the supplier to confirm the full-model revision, maximum value and method note, applicable input\/load conditions and any recommended interpretation of transient equipment states. Send the actual setup description with a trace rather than just the trace. If the source and measurement methods disagree, resolve that gap before concluding the supply is defective.<\/p>\n<figure><img loading decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/03-product-detail-3.png?quality=85&strip=all\" alt=\"Power Supply Ripple Measurement: Match Bandwidth, Probe Loop and Output Loading First  title=\" width=\"1536\" height=\"1024\" power supply ripple measurement: match probe loop and output first title =\"\"><figcaption>Authentic right-side source detail with the real MDR-20-24 model plate, upper terminal entry and blue vent pattern. The view comes from the approved close-up photograph; no label has been sharpened, replaced or moved.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Frequently_asked_questions\"><\/span>Frequently asked questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Does_150mV_peak-to-peak_mean_every_oscilloscope_view_must_show_that_or_less\"><\/span>Does 150mV peak-to-peak mean every oscilloscope view must show that or less?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The stated limit belongs with its documented conditions. An observation made elsewhere or with another setup cannot be treated as the same test without qualification.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_an_article_image_prove_the_supply_passed_the_test\"><\/span>Can an article image prove the supply passed the test?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. These are application illustrations. A test claim needs an actual trace and reproducible condition record tied to the unit.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Does_the_approved_PDF_contain_the_complete_probe_note\"><\/span>Does the approved PDF contain the complete probe note?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The adopted full sheet gives the model table and geometry; the detailed ripple-network note was obtained from the official English page. Both provenance paths are retained rather than pretending they are the same document.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Sources_and_revision_boundary\"><\/span>Sources and revision boundary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.wehopower.com\/el\/product\/100-guarantee-mdr-series-20w-5v-12v-24v-switching-power-supply\/\">WEHO MDR-20 English product page<\/a>, reviewed 8 October 2026; exact approved enterprise-drive MDR-20\/1.jpg,5.jpg and rear-mount source 3.jpg; complete MDR-20 electrical\/mechanical specification. Physical input 100\u2013240VAC0.55A is retained literally; the sheet\u2019s wider input-range language is not a rewritten nameplate. No performed test, system certification or remote-load guarantee is asserted.<\/p>","protected":false},"excerpt":{"rendered":"<p>Document the MDR20 measurement conditions before treating an oscilloscope trace as comparable ripple evidence.<\/p>","protected":false},"author":2,"featured_media":18809,"parent":0,"menu_order":19,"comment_status":"","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[149,284],"class_list":["post-18813","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-blog","news_category-product-articles","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news\/18813","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/comments?post=18813"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news\/18813\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/media\/18809"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/media?parent=18813"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/el\/wp-json\/wp\/v2\/news_category?post=18813"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}