As shown in the figure, it can only be seen that it is related to power control, but I don't know how to analyze the control principle.
Shay 게시 날짜 August 5, 2020
A very simple power MOS switch circuit, the MOS switch is driven by a transistor in the reverse direction.
Ellison 게시 날짜 August 5, 2020
Input low level, the triode does not conduct, PMOS tube VG=VS, VGS=0 PMOS tube does not conduct; input high level, three-level light conduction, VG<VS, VGS<VT, PMOS tube conduction, output Voltage 12V.
Collins 게시 날짜 August 5, 2020
The principle of this circuit is as follows: when Q2 1 pin inputs a high level, Q2 is turned on, so that the third pin of Q2 is low, so the first pin of Q1 is low, and the second pin of Q1 is high. When Q2 is turned on, the voltage of Vcc-Panel is 5V or 12V on the left. When Q2 1 pin inputs low level, Q2 is not turned on, then Q1 is not turned on, so Vcc-Panel is 0V.