The circuit relatively simple circuit adapter (DC-DC converter), which increases the voltage-board vehicle network to 19V, needed to supply the laptop. And maintain this voltage stable. The adapter is based on chip LM3524, which is a high-frequency switching DC-DC converter with pumped inductance and output current up to 200mA, the output current which, in this scheme, will increased to 3.5-4A using a powerful transistor switch (on transistors VT1 and VT2).
