Does anyone know a simple way to build a high efficiency 12v to 5v converter? I built a power supply using a radio shack voltage regulator but the heat was too much for my application. From my internet search it appears that what I need is a switch mode power supply but as a relative newbee I don't know how to build one. Does anybody have a simple schematic of one? Thanks!

 

Why don't you tell us what your load current requirement is?

 

You can buy them. They're called car USB power supplies. Most use the MC34063A IC and are built like the step-down converter shown on page 8 of the data sheet.

http://focus.ti.com/lit/ds/symlink/mc34063a.pdf

 

Sorry, brand new to this site. Thought I posted in the right area. Guess not!

 

Sorry, brand new to this site. Thought I posted in the right area. Guess not!

Huh? What makes you think this isn't the right place for your question? Because you were asked to supply a basic specification, to define what you need? We can't read your mind.

 

Usually, we need such parameters such as input voltage range, output voltage (range), and a range of load current. Without these parameters, we could spend some time coming up with a solution that would not be appropriate for you.

The MC34063 is a pretty nifty IC, but it has a limited output current range.