I found this data on the eleccircuit.com web site. There does not seem to be a name associated with the design. In a nut shell it will drop 12vdc to 5 vdc @ 3 amps output. Fail safe circuitry is in place for short and overload. I have built and tested this with the pi and it works very well. The only issue is to be sure to use a 1/2 watt or higher for R5. 1/4 got quite warm but ran ok when 2 were used in parallel. I'm also using a 10 watt for R4. I added 2 green leds to indicate power out is on. On short or overload green led goes out and red led turns on indicating a fault condition.