This is a small and light weight Battery Eliminator Circuits(BEC).The heart of this project are four very low dropout linear regulator L4941.The DPAK packages to be used in this project. L4941 Feature summary - Low dropout voltage (450mV typ. at 1A) - Very low quiescent current - Thermal shutdown - Short circuit protection - Reverse polarity protection Data sheet L4941 The data sheet in pdf format Because I need 4A output so I use L4941 x 4 connected in parallel on the single layer PCB.If you worry about the heat that dissipated by L4941 you should mount the small heat sink at the top of IC. but increase a litle weight. PCB for this project All PCB are pdf format included posistive, negative buttom and overlay.