{"id":670,"date":"2016-09-25T19:42:40","date_gmt":"2016-09-25T18:42:40","guid":{"rendered":"http:\/\/www.mb200d.nl\/wordpress\/?p=670"},"modified":"2016-10-11T21:45:23","modified_gmt":"2016-10-11T20:45:23","slug":"lm2576t-5-step-down-switching-regulator","status":"publish","type":"post","link":"http:\/\/www.mb200d.nl\/wordpress\/2016\/09\/lm2576t-5-step-down-switching-regulator\/","title":{"rendered":"LM2576T-5 step down switching regulator"},"content":{"rendered":"

First switching power supply working.<\/p>\n

I have an ARM board to be powered, which draws between 0.5 and 1.5 ampere’s on 5 volt. Tried using an standard 7805 (2 ampere spec), but the system would not boot. VOut dropped to 4.5 volts and 7805 was getting to hot with +\/- 24 volt VIn.<\/p>\n

So i made an circuit based on the LM2576T-5.<\/p>\n

Partslist:<\/p>\n\n\n\n\n\n\n\n\n\n
Part<\/strong><\/td>\nPrice<\/strong><\/td>\n<\/tr>\n
IC1: LM2576T-5<\/td>\n\u20ac 1,60<\/td>\n<\/tr>\n
L1: Inductor 100uH<\/td>\n\u20ac 1,45<\/td>\n<\/tr>\n
D1: SR504<\/td>\nRecoverd from PC PSU<\/td>\n5.0 Amps Schottky Barrier Rectifier<\/a><\/td>\n<\/tr>\n
C1: 470uF 35v<\/td>\nReused from other project<\/td>\n<\/tr>\n
C2: 3300uF 10v<\/td>\nAlso recovered from PC PSU<\/td>\n<\/tr>\n
F1: Fuse holder and 400mA<\/td>\nStock, price n\/a<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\"lm2576t-5-schema\"<\/a>Input voltage is an battery+solar power supply that varies between 23-24 to 29 volts.<\/p>\n

Working power supply (left) with active load.
\n\"img_20160925_184405_edit\"<\/a><\/p>\n

Bad output: (spikes)<\/b>
\nWhat happens if an normal (or to slow) diode is used:
\nYellow is regulator V-OUT.
\nBlue line represents voltage output for load (feedback signal).<\/p>\n

\"img_20160924_194739_edit\"<\/a><\/p>\n

Good output:<\/b>
\nNo load:<\/p>\n

\"noload\"<\/a><\/p>\n

100mA load<\/p>\n

\"100ma_load\"<\/a><\/p>\n

 <\/p>\n

Borrowed lm2576 library for Eagle PCB Design<\/a> from eaglecentral.ca | LM2576 circuit<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

First switching power supply working. I have an ARM board to be powered, which draws between 0.5 and 1.5 ampere’s on 5 volt. Tried using an standard 7805 (2 ampere spec), but the system would not boot. VOut dropped to 4.5 volts and 7805 was getting to hot with +\/- 24 volt VIn. So i […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[327,13,1,146],"tags":[329,330,332,331,333],"class_list":["post-670","post","type-post","status-publish","format-standard","hentry","category-electronics","category-english","category-robin","category-solar-energy","tag-lm2576","tag-lm2576t-5","tag-mini2440-arm-board","tag-psu","tag-smps"],"_links":{"self":[{"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/posts\/670","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/comments?post=670"}],"version-history":[{"count":5,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/posts\/670\/revisions"}],"predecessor-version":[{"id":682,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/posts\/670\/revisions\/682"}],"wp:attachment":[{"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/media?parent=670"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/categories?post=670"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.mb200d.nl\/wordpress\/wp-json\/wp\/v2\/tags?post=670"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}