aksnis

Hello everyone, I was studying a tl494 based half bridge smps I came across the current sense section opamp pin 15 & pin16 Now pin16 is connected directly to the ground But there is some arrangment made to pin 15 I have drawn a part of it Please can anyone help me what is a purpose of “103 trimpot” and why does the transistor “ 2n2222a” is also used which Is connected to microcontroller pic18f452

Hello I am trying to repair a smps power supply based on UC3825A Problem is the resistor R49 & R34 get burst as soon as i start the smps I am not able to find out the issue SYS_ECON is a 0-5v given from MCU desired by user to control 0-180v smps output