{"id":9283,"date":"2020-06-14T17:21:45","date_gmt":"2020-06-14T17:21:45","guid":{"rendered":"https:\/\/stevepedwards.today\/stevepedwards.com\/ElectronicsStuff\/?p=9283"},"modified":"2020-06-14T17:21:45","modified_gmt":"2020-06-14T17:21:45","slug":"op-amp-test-transfer-characteristics-by-xy-mode","status":"publish","type":"post","link":"https:\/\/stevepedwards.today\/ElectronicsStuff\/op-amp-test-transfer-characteristics-by-xy-mode\/","title":{"rendered":"Op Amp Test &#8211; Transfer Characteristics by XY Mode"},"content":{"rendered":"<p>I spent ages - as usual for me! - arsing about and getting nowhere with this circuit (and my crappy Hantek DSO 5102P scope and it's usual lockup and odd behaviour type hassle, hopefully improved after a firmware update!) from page 109 of GC Loveday's Electronic Testing book - should have been straight forward right - as easy as a circuit gets?!:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9462 size-large\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/p109-e1592154661644-576x1024.jpg\" alt=\"\" width=\"576\" height=\"1024\" \/><br \/>\nThere is no Y component from this circuit as pin 1 out is grounded by the pull up resistor so has no amplitude no? I'm wondering if the +\/- invert signs are error switched - though the output pin 1 is fixed the same as the inverting pin 2, with the input at non-inverting pin 3 should still work eh?But, I only got a flat line in XY mode at a 20Hz ramp so don't know why this doesn't work - even at 10Hz or 1kHz sine\/ramp\/triangle...nothing?<br \/>\nDo you have to have the sig gen gain cranked up more...as I found I was doing below for the working versions??<br \/>\nI finally made some progress with the simplest way possible to view the op amp's-\u00a0 output, from this guy, by using the inverting input instead with the non inverting input at ground:<br \/>\n<iframe loading=\"lazy\" title=\"Transfer characteristics\" width=\"1333\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/o1IAiYtUzb8?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><br \/>\nThis shows NO components required - just a 1-2Vpp sine wave (2kHz worked best for me) in and out (pins 2-; 1 out; 3+ to ground of a +\/- 15.7V supply) to give the clearest view of the slope at my scope's settings).<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9463\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/IMG_20200614_175720499_HDR-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\nThis gave me the same as him at least - digital scopes are crap in XY mode display, at best - and after trying different wave forms at different cycles\/sec I found 2kHz best:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9464\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/IMG_20200614_175810158-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\nThis output is from the M5219P tone amp from the Technics V1X - total symmetry as you'd expect.<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9465\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/IMG_20200614_175836282-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9466\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/IMG_20200614_175853745-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\nThis method can be used to test an op amp quickly on a bread board without building a circuit board - if you lost your tester you already built..?<br \/>\nLM358s at 20Hz looks like:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9471\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/lm358-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><br \/>\nAfter changing Vcc to pin 7 and output to pin 6, the 741 op amp at 20Hz looks like:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-9470\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2020\/06\/IMG_20200614_190046649-1024x576.jpg\" alt=\"\" width=\"840\" height=\"473\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I spent ages - as usual for me! - arsing about and getting nowhere with this circuit (and my crappy Hantek DSO 5102P scope and it's usual lockup and odd behaviour type hassle, hopefully improved after a firmware update!) from page 109 of GC Loveday's Electronic Testing book - should have been straight forward right <a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/op-amp-test-transfer-characteristics-by-xy-mode\/\" class=\"more-link\">...<span class=\"screen-reader-text\">  Op Amp Test &#8211; Transfer Characteristics by XY Mode<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-9283","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9283","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/comments?post=9283"}],"version-history":[{"count":0,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9283\/revisions"}],"wp:attachment":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/media?parent=9283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/categories?post=9283"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/tags?post=9283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}