![\"null\"](\"http:\/\/micro-trike.co.uk\/images\/weedmicro_01.jpg\")
<\/a><\/p>\nThe components were quite inexpensive. All of the inline components came in multi-packs (mostly 20s and 50s but just 5 for things like the transistor and diode) and as I bought two of the Arduino microprocessors, the second when I realised that the first one that I’d ordered was going to take weeks to come direct from China, I only had to order a second integrated circuit when it arrived to be able to make a second complete unit.<\/p>\n
It occurred to me that this was quite a good idea. 28AAD, my French Weedhopper, uses G-MYRO’s old instrument panel which incorporates an hour meter that runs in the old-fashioned way from the charging circuit incorporating a very large capacitor, presumably so the meter only started running after a threshold voltage had been attained. You can see it in the following pic that I took way back when I was originally rebuilding MYRO.<\/p>\n
The problem was that the system has never worked correctly. When I initially got MYRO back in the air, the hour meter ran for a very short time and then stopped, never to go again. I didn’t bother finding out why and just recorded engine and airframe hours in the relevant log books from the figures that I took down at the time.<\/p>\n I thought that it was maybe down to just a bad connection, but now I don’t think that that was the reason, because exactly the same thing has happened again now that the panel is being used again in 28AAD. I suspect that the problem is down to the large capacitor deteriorating with age. It actually didn’t originally come from MYRO but instead from the AX3 whose panel I acquired to replace MYRO’s old one that was in a very bad state.<\/p>\n But in any case, it is now over 20 years old so is probably not working at all in the way that it is supposed to. So that gave me the idea that rather than waste the components for the second little microelectronic guizmo, I should instead use them to make a second unit to replace the capacitor in 28AAD’s hour meter circuit and get it working again, and that’s precisely what I’ve done.<\/p>\n Here’s a shot of the reverse of the unit showing the soldering – not very pretty maybe, but it works fine and won’t be visible and therefore won’t matter when the circuitry has been potted in clear silicone.<\/p>\n And here’s a shot of the unit with its connector in place.<\/p>\n My ‘Version 2’ is slightly shorter than my original because this time, on the advice of Sean in the UK who provided me with the circuit details and the programming, I’ve ‘hidden’ some components in the space under the Arduino microprocessor. Here are the details of the circuit and my layout.<\/p>\n As 28AAD has a Rotax 503 2-stroke engine that runs at higher revs than my Savannah’s 912S, I’ve programmed the microprocessor differently, for the hour meter to begin reading at 4000 rpm and to stop at 2000 rpm. This is because the 503 engine typically warms up at 3000 rpm and the revs only then fall to 2000 when its being switched off after taxying in. <\/p>\n I’ll be finishing the unit off tomorrow, probably, while the weather is still unsettled and I’m looking forward to seeing how it then performs when installed in 28AAD.<\/p>\n","protected":false},"excerpt":{"rendered":" Here’s the latest incarnation of the little microelectronic guizmo that I installed in my Savannah to control its hour meter. The components were quite inexpensive. All of the inline components came in multi-packs (mostly 20s and 50s but just 5 for things like the transistor and diode) and as I bought two of the Arduino … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-15242","post","type-post","status-publish","format-standard","hentry","category-main-blog"],"_links":{"self":[{"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/15242","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/comments?post=15242"}],"version-history":[{"count":10,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/15242\/revisions"}],"predecessor-version":[{"id":15252,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/posts\/15242\/revisions\/15252"}],"wp:attachment":[{"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/media?parent=15242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/categories?post=15242"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.micro-trike.co.uk\/wordpress\/wp-json\/wp\/v2\/tags?post=15242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n<\/a><\/p>\n