DC to DC Buck converter- I need to know where can I get quality one - Page 1
Forum section: electronics / projects

author: eevblogfan
author_rank: Frequent Contributor
timestamp: December 28, 2013, 05:38:29 am
content: HeyI have got small project , I need to mode 100 electric bikes with winkers and proper reliability , so I am going to add on to the biggy battery ,specs :on mode : up to ~0.7Awinker mode : ~0.5Ainput voltage:~36V ( up to 42V sometimes when charged )circuit demands : 12Vso I thought to use one of the chickpeas cards on ebay . but their input ratings sucks , so I thought to add LM317 to the circuit and "regulate" 30V out , then those small cards should live fine ,so the next question is reliability of the system , sine those small cards are not High quality , I am doubted them ,so please , some one can tell me where is A good place high quality Buck converters ? , preferably 70V input ratings or so , I know budget and country are not mentioned , so here they are :country : Israelbudget . I should be told this evening , but for now . lets say 10~20$ per card just for good resultspreferably 5$ on 100 of quantity@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Update : Digikey didn't gave me sane result - so unless I missed it nor don't know how to fiend those small golden products hidden in the parametric search , I'd love one to correct me hereif I may , Aldo some good DPDT toggle quality switch won't hurtspecs :1A or soon/off/onbrake before makeBudget: 1~5$ ( depends ) - 100 of quantity

author: mariush
author_rank: Super Contributor
timestamp: December 28, 2013, 07:28:06 am
content: Why don't you make them from scratch?2-3$ a piece for a dc-dc switching regulator capable of at least 55v input :http://uk.farnell.com/texas-instruments/lm2575hvs-adj/ic-dc-dc-converter/dp/16523871-1.5$ capacitors, resistors, shottky diode, inductor etc<0.5$ pcb for pcb or 20-50$ per panel (and you can squeeze a lot of individual boards on each panel)

author: eevblogfan
author_rank: Frequent Contributor
timestamp: December 28, 2013, 01:33:19 pm
content: MTBF is simply why ...this is not one of project of mine ... it's one of job ...

author: AlanR
author_rank: Regular Contributor
timestamp: December 28, 2013, 01:46:29 pm
content: http://www.digikey.com/product-search/en?pv1120=225&FV=fff40042%2Cfff800df%2C8f40011%2C17d4002c&k=dc-dc&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25There you go. Has a MTBF rating of 1 million hours also.

author: ovnr
author_rank: Frequent Contributor
timestamp: December 28, 2013, 02:37:59 pm
content: Quote from: AlanR on December 28, 2013, 01:46:29 pmA bit expensive, isn't it? You can find a cheaper solution, likethis one- 18-75V to 12V @ 1.3A, MTBF >7M hours. $18 one-off, $16 in larger quantities.I'd personally probably build a custom solution though. Will be cheaper in the long run.

author: AlanR
author_rank: Regular Contributor
timestamp: December 28, 2013, 03:06:03 pm
content: Quote from: ovnr on December 28, 2013, 02:37:59 pmsigh... Digikey can be a confusing beast. There have been times that I have found aerospace grade or military grade parts be cheaper compared to the same parts in commercial grade. They should have a price search filter implemented ASAP.