MOV transient protection and electronic current limiting Acceleration: Adjustable from 0.5 to 4 seconds JYMC-220B-I Wiring & Schematic Overview
The accurate voltage regulation comes from an (IC2, PC817) and a TL431 programmable shunt regulator on the secondary side. The schematic routes the main output voltage through a resistor divider into the TL431's reference pin. If the voltage rises, the TL431 conducts more, pulling current through the optocoupler's LED, which dims the PWM on the primary side. jymc-220b-i schematic
The JYMC-220B-I is a dual-output, flyback topology SMPS. Its primary application is supplying a main voltage (typically 12V or 24V at 3-5A) and a standby voltage (5VSB at 0.5-1A). It is often paired with a separate LED backlight driver board, though some revisions include a basic backlight enable circuit. The JYMC-220B-I is a dual-output, flyback topology SMPS
The board uses a combination of main power terminals and smaller control pins for various functions: The board uses a combination of main power
R10 (sense resistor) opens, Q1 shorts, and IC1 dies. In this case, replace all three as a set.