This part is a kind of semiconductor called STR-W6750F.

Function of this product has Power IC.

Manufacturers : Sanken

Image and pinout :

Some of the text within the PDF file :

Power IC for Quasi-Resonant Type Switching Power Supply with High Efficiency and Low Noise in Full Load Range STR-W6750F ◆General description The STR-W6750F is power IC for quasi-resonant type switching power supply, incorporating a power MOSFET and a controller IC. The product achieves high efficiency and low noise power supply systems by the quasi-resonant operation. Sep. 2013 ◆Package Package name: TO-220F-6L (FM207) ◆Features  Quasi-resonant operation mode Achieves the optimal high efficiency and low noise power supply systems.  Current mode control  Built-in PWM oscillator The PWM operates with the minimum frequency of around 22kHz, until the quasi-resonant signal becomes valid, reduces the stress on components at startup and load-shorted.  Built-in soft start fu [ ... ]

STR-W6750F PDF Datasheet Download