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Electronics => Electronics => Topic started by: karmax on December 21, 2008, 12:37:08 AM

Title: how to make 12v supply at 8 amp
Post by: karmax on December 21, 2008, 12:37:08 AM
hi guys.. i have 24 v battery  and i want 12v for giving power to my SBC(single board computer) . it takes 8A current so i cant use 7812. so give me any good idea. and tell me also for 10A.
Title: Re: how to make 12v supply at 8 amp
Post by: cosminprund on December 21, 2008, 02:22:12 AM
An linear power regulator would drop 12V from that battery. 12 Volts x 8Amps = 96W  ::) That's huge (try to put your hand on a 100W lite bulb). Get a switching power regulator OR get a different battery.
Title: Re: how to make 12v supply at 8 amp
Post by: Admin on January 14, 2009, 11:26:34 AM
sounds like you need a PC power supply . . . there aren't any regulator ICs that can handle 8A!
Title: Re: how to make 12v supply at 8 amp
Post by: want2learn on January 14, 2009, 01:40:47 PM
Try to find a part like this one:

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1042,C1116,P10090,D7197

I'm not going to say this is the one you need but the datasheet tells you everything you need to know to build a circuit with this chip (it even tells you how to select the transistors you need for your current output).

I prefer regulators like this because I can select the chip with the features I want then select the output I want (way easier than trying to find one chip with everything :) )
Title: Re: how to make 12v supply at 8 amp
Post by: Admin on January 14, 2009, 09:03:36 PM
Try to find a part like this one:

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1042,C1116,P10090,D7197

That chip does peak 3A . . .

Another option would be to put several voltage regulators in parallel.
Title: Re: how to make 12v supply at 8 amp
Post by: want2learn on January 14, 2009, 11:50:12 PM

That chip does peak 3A . . .


Yes Admin the chip does peak at 3A, BUT thats only the supply to the switching transistors, which can switch any maximum current rating you desire.
As long as the gate supply doesn't need more than 700mA each and you can match the transistors charachteristics to the ones you will calculate further down in the datasheet.

There are many switching regulator I.C.s that use external transistors, that was just one of them  :)