DC-DC Buck controller with LM 5115?

[domwild]

The LM5115 has been recommended by GoAhead as a solution to our varying input voltage problems with mills/hydros:

LM5115 <= 75 V input, 20 A, output to 13.5V

As GoAhead's request for a cicuit was at the end of SouthEast's request, it might have been ignored. My electronic knowledge is insufficient, so I cannot help but this LM5115 looks like a winner.

Have also contacted SiliconChip, our Aussie magazine with a request to come up with a circuit for us and I cannot remember, which chip I suggested. It was one from Linear Technology or National so we may see something from them perhaps.

Any takers to build us a circuit? I understand this could be a very tall order.

Regards,

[ghurd]

A problem?

What happens when the battery only needs 1A to maintain 13.5V,

But the windmill is trying to make 10A at 60V?

I think implementing the circuit will have some far reaching effects past the obvious.

G-

[Goahead]

Hi everyone

Thank you Domwild to bring this to discussion alive again.

My knowledge in power managment electronics is also low, but i dont understand what is the problem pointed here...

http://www.otherpower.com/images/scimages/8828/Windmill_Topology.JPG

With simple battery charger controller that we can find and build (that includes a relay for the dump load), we can change values of components so it to stop charging battery at 13 volts or near the 13,5 and start charging only when reaching +/- 11,8volt again... correct?

I now 13V is a bit low, and it should be 13,8volts for perfect charging but its not a problem at all. (battery will be charged at only 99% but it will not heat and burn with 60v 20A if we connect widmill direct to battery).

Main problem in batterys is that they dont like to be discharged in a long period or below 10volts..but what we are talking here is about not charging at 100% but only 99%.

Am i saying something stupid here? Like i said..im dont have experience in power management

http://www.otherpower.com/images/scimages/8828/Switching_V1.JPG

Help needed...

Check LM5115 datasheet and help me out in this..

Is circuit ok?

What values do i use for Resistors and capacitors?

What voltage should be privided in Vbias, RAMP,SS and CO pins?

Can i get that voltage from the final output?

Regards

Goahead

[Goahead]

Some ideas:

https://courses.ece.uiuc.edu/ece445/?g=Home&p=Projects

Look for DC-DC wind power...

There are several projects for DC step down converters...

Theres at least one with 83% efficient

Its not hard to make one from scratch

Goahead