Back to the Thing optoboard this evening. I re-attached it to its connector (having used electrical tape to simulate an open Opto 1 switch) and turned the machine on and tested the switches. Sure enough the “left-outlane\/Thing-up opto-switch” problem was still evident. However, now that the board was “free” I noticed that by simply moving the board I could get the opto switch to switch temporarily. Maybe this was related to the underlying problem?<\/p>\n
I tried to identify which component on the board or wire leading to the board was causing this switching, but couldn’t locate it. Whenever I thought I had, it turned out it wasn’t in fact there. How frustrating! However, I then noticed that the 1N4004 diode on the board was uncomfortably hot! This definitely shouldn’t be the case. This diode (according to its spec) can take 1 Amp. On the board were two 470 ohm resistors, so even though I didn’t have the circuit diagram, I assume (although I may be wrong here) that the maximum current flow through the diode should be 12V\/470ohm = 25mA. This shouldn’t cause a diode to overheat. I measured both resistors in situ and measured 470 ohm +\/- 5%.<\/p>\n
So I desoldered the diode from the board (burning my finger in the process) and measured its resistance in both directions. It seems to be OK, but this overheating is something I don’t like.<\/p>\n
So I’ve now ordered some new diodes from Conrad and have tried to get a circuit diagramme of the optoboard from the forum flippertreff.de – but without any success to-date.<\/p>\n","protected":false},"excerpt":{"rendered":"
Back to the Thing optoboard this evening. I re-attached it to its connector (having used electrical tape to simulate an open Opto 1 switch) and turned the machine on and tested the switches. Sure enough the “left-outlane\/Thing-up opto-switch” problem was still evident. However, now that the board was “free” I noticed that by simply moving […]<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-137","post","type-post","status-publish","format-standard","hentry","category-taf"],"_links":{"self":[{"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/posts\/137","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/users\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=137"}],"version-history":[{"count":5,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/posts\/137\/revisions"}],"predecessor-version":[{"id":1757,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=\/wp\/v2\/posts\/137\/revisions\/1757"}],"wp:attachment":[{"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=137"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=137"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/taf.gozzled.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=137"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}