This part is a kind of semiconductor called 1N5918.Function of this product has Diode Zener Single 5.1V 20% 1.5W 2-Pin DO-41. Manufacturers : New Jersey Semiconductor Image and pinout : Some of the text within the PDF file : [ ... ] 1N5918 PDF Datasheet Download Metablog 2017/10/27 20:19 2017/10/27 20:19