Author Topic: DC to DC Buck converter- I need to know where can I get quality one  (Read 2706 times)

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Offline eevblogfanTopic starter

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Hey

I 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 ~0.7A
winker mode : ~0.5A

input voltage:~36V ( up to 42V sometimes when charged )
circuit demands : 12V

so 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 : Israel
budget . I should be told this evening , but for now . lets say 10~20$ per card just for good results
 
preferably 5$ on 100 of quantity

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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 here

if I may , Aldo some good DPDT toggle quality switch won't hurt

specs :
1A or so
on/off/on
brake before make

Budget: 1~5$ ( depends ) - 100 of quantity

« Last Edit: December 28, 2013, 05:54:39 am by eevblogfan »
 

Offline mariush

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Re: DC to DC Buck converter- I need to know where can I get quality one
« Reply #1 on: December 28, 2013, 07:28:06 am »
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/1652387

1-1.5$ 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)

 

Offline eevblogfanTopic starter

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Re: DC to DC Buck converter- I need to know where can I get quality one
« Reply #2 on: December 28, 2013, 01:33:19 pm »
MTBF is simply why ...

this is not one of project of mine ... it's one of job ...
 

Offline AlanR

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« Last Edit: December 28, 2013, 01:49:24 pm by AlanR »
 

Offline ovnr

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Re: DC to DC Buck converter- I need to know where can I get quality one
« Reply #4 on: December 28, 2013, 02:37:59 pm »
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=25


There you go. Has a MTBF rating of 1 million hours also.

A bit expensive, isn't it? You can find a cheaper solution, like this 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.
 

Offline AlanR

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Re: DC to DC Buck converter- I need to know where can I get quality one
« Reply #5 on: December 28, 2013, 03:06:03 pm »
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=25


There you go. Has a MTBF rating of 1 million hours also.

A bit expensive, isn't it? You can find a cheaper solution, like this 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.


sigh... 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.  |O
 


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