This part is a kind of semiconductor called 78R12.
Function of this product has 1A Fixed 12V Low Dropout Voltage Regulator.
Manufacturers : Fairchild Semiconductor
Image and pinout :
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www.fairchildsemi.com KA78R12 Low Dropout Voltage Regulator Features • 1A / 12V Output low dropout voltage regulator • TO220 Full-Mold package (4PIN) • Overcurrent protection, Thermal shutdown • Overvoltage protection, Short-Circuit protection • With output disable function Description The KA78R12 is a low-dropout voltage regulator suitable for various electronic equipments. It provides constant voltage power source with TO-220 4 lead full mold package. Dropout voltage of KA78R12 is below 0.5V in full rated current(1A). This regulator has various function such as peak current protection, thermal shut down, overvoltage protection and output disable function. TO-220F-4L 1 1. Vin 2. Vo 3. GND 4. Vdis Internal Block Diagram Q1 Vin 1 2 Vo THERMAL SHUTDO [ ... ]