Thread: 12v regulator / conditioner circuit

we're all looking for something which can do something like this..

All the people who make their own dc-dc's would be very happy.

you could use a LM2587-12T from national semiconductor but this will give you only 1,2A Max (maybe for a short time it will handle 2A )

If you got an solutions to produce regulated 12v supply @ 5A please share it with us, 'cause we don't have anything like it.

Hope this helps you out...
Greetz

I don't understand why you people don't want to use MAX1771 regulator.This seems to be the easiest way to do it (since not all of us can get parts for LM2587). I'm using 2 of them,and I get a peak current of 4.5A (for about 10 sec),I think this should be enough for all applications...
We all want a simple solution, some chip that will take 8-16v as input and produce stable 12v output at 4-5A! There is no such part that can do it! So we have to integrate some parts together.
I'm working in telecom company,and we work a lot with power supplyes,but in different range.The range that we want, 8-16v, is quite problematic,because we need 12v.So I discussed a lot with engineers in my work about how should I build the 12v supply.Because we use voltages that are below or equal to 12v, the best and the most efficient way is to use flyback regulator,like Sproggy's design. But his supply can only supply 1.5 A for 12v because he use Q4339 transformer. I heard that someone,I think it was Fosgate,replaced this transformer with 1:1 transformer and managed to get more current.
The alternate way,as engeneers suggested,is to use MAX1771,in his bootstrapped mode (see its datasheet).This is less efficient and requires strong FET,but I prefer it because of easy-to-get parts.

Hi, could you post a pic of your circuit? I think we all would like to know how you use those 1771... I don't understand "bootstrap"....

cheers!

Yes,
Would be very nice to see it..
Doesn't matter if it isn't that efficient..
As long as it is more efficient than dc-ac-dc...

Greetz

right.. it is called 5A switchmode regulator
But it just can't provide this at 12v (it can at voltages like 5v or something, but not with the 12v)

And, if my memory serves me right, I think someone mentioned earlier that it has got something to do with the T6 coil. But I don't know for sure . (so don't blame me )

But maybe this max1771 could do the trick

Greetz

skinny boy: not right.

the whole LM2587-series is 5A max. the LM2587-5 delivers the 5A max, the LM2587-12 delivers 1.2A, on national's site there is a simulator somewhere which lets you type in your requerments.. I've been playing around with it and max 1.5A was absolute max you can get from it @ 12V..

So, I think it could supply a peak of 5amps at 12volts...

You shouldn't think too much...
Gives you headache's

Greetz