The OP-AMP (the upside one ) output will be trought a shotky diode then to fb pin of a buck comverter I.C . in my case XL4015 . this VOLTAGE to the fb pin will command the I.C to lower the voltage of his output when the current adjusted by potentiometer in the inverting input , this circuit will give 3.3V on the fb i.c that will force him to lower the voltage , THAT'S HAPENING OVER AND OVER AGAIN ( in Khz ) , until the output current it-s stabilizet to what you chosen by INVERTING pin of 1nd OP AMP . that-s how it works . about 2nd OP-AMP ...IT's just for indicate over current and not-over-current .
THIS WORK PRINCIPLES IT'S BASED ON DROP VOLTAGE OF POWER RESISTANCE (up side one )
AT left leg of power R will be the output of BUCK I.C and left leg to the LOAD .
IT'S A CHEAP AND EASY CURRENT LIMITING CIRCUIT
SO MANY PEOPLES TOLD ME TO EXPLAIN THE CIRCUIT , NOT JUST POST IT .
SO , I APOLOGISE MY ENGLISH GRAMMATICAL - I'M ROMANIAN .
By Allexandru Prroca
