This part is a kind of semiconductor called DPC-817C.
Function of this product has PHOTOTRANSISTOR / PHOTOCOUPLER.
Manufacturers : KeepJump
Image and pinout :
Some of the text within the PDF file :
PHOTOTRANSISTOR / PHOTOCOUPLER DPC‐817C KeepJump International Technology Limited 1 http://www.keepjump.com.tw DPC‐817C KeepJump International Technology Limited 2 http://www.keepjump.com.tw DPC‐817C KeepJump International Technology Limited 3 http://www.keepjump.com.tw DPC‐817C KeepJump International Technology Limited 4 http://www.keepjump.com.tw DPC‐817C KeepJump International Technology Limited 5 http://www.keepjump.com.tw [ ... ]