Hi, I'm new to the group and wonder if anyone can recommend a switch that will give me 12.6v output from 10-14v (12v lead acid battery). I would like 5A output and even up to 10A if possible, but may also accept only 3A for a simple solution. In going through some of the options on National, Microchip, etc, my greatest challenge seems to be finding a solution that makes current easy to vary (eg: with a pot or discrete resisters).
My application is a 3 cell lithium charger. The primary requirement is constant voltage while not exceeding current appropriate to the cells on charge (I have a variety of sizes to charge). I have a fairly solid understanding of lithium charging requirements and the risks associated with these cells. Although I can get help with SMT chips they must at least have leads! and I would prefer bigger stuff.
I have a successful LM2577 based design which takes the voltage up to about 16v and then I use an L200 to bring it down to 12.6v. The L200 also gives me control over output current with a resister array. This works well at lower currents but I now want higher currents and would prefer to avoid the step-up then -down design. I don't have the knowledge to design my own high output stages so am hoping that you folk can offer some advice. Thank you, David.