This post explains for the semiconductor STR-5412.
The Part Number is STR5412.
The function of this semiconductor is Switching Power Supply.
The package is ZIP 5 Pin Type
Preview images :
This is switching power supply for TV. We are going to analyze the work of a switching power supply, which makes use of the STR5412 hybrid circuit.
First of all, we will describe what this hybrid circuit consists of, whose equivalent diagram can be seen in figure 1. Its main concept can be defined as “a switch
of current in series configuration”, arranged between its pins 1 and 4; the switch is made up of a power transistor Q1. The base of Q1 is connected to pin 2 and through it the aforementioned element will be made to conduct.
In order to prevent Q1 from entering the conductive state, the circuit makes use of a second transistor Q3, the actuation of which allows the base bias of Q1 to be short-circuited.
In turn, the control of Q3 is governed by the presence of transistor Q2, which works configured as an error amplifier, whose emitter voltage is controlled by a zener diode – Dz – and its base circuit works by measuring or comparing the voltage output through a resistive type network.
1. TROUBLESHOOTING AND REPAIR
2. TV SWITCHING SOURCES
3. SWITCHING POWER SOURCE