This part is a kind of semiconductor called 57BYGH802.
Function of this product has HYBRID STEP MOTOR.
Manufacturers : MERCURY MOTOR
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Some of the text within the PDF file :
MERCURY MOTOR ST-57BYGH 1.8°HYBRID STEP MOTOR Dimensions (Unit: Millimeter) Step Agle Insultion Resistant Insultion Strength Ambient Temperature Temperature Rise Radial Play End Play 1.8°±5% 500V DC 100MΩ Min 50Hz 1Minute 500V Min -20℃~+50℃ 80℃ Max. 0.02mm Max. 0.1-0.3mm Electrical Specifications Phase Current Resistance Number (A) (Ω) 4 2 4 4 4 2 4 4 4 4 2 4 2 4 2 4 4 2 4 4 2 4 2 2 2 4 4 2 4 4 0.34 0.4 2 0.38 2.3 2.5 3 0.4 1.6 1.6 1 1 1 2.5 1.4 3 2.3 2 3 3 3 2.5 3.3 0.4 0.4 2.5 3 3 1.5 1.5 71 35.5 1.4 32 1.1 1.1 0.75 30 2.2 2.6 3.5 6.2 8.2 1.3 4.2 1 2.5 4.3 1.2 1 1.4 1.8 1 38 80 2.2 1.2 1.2 3.2 4.2 Inductance Max.Static torque (kg.cm) 4.4 5.6 4.2 6 8.2 9.8 9 8 8 9 9 9 10 8 15 13 16 24 15 13.5 18 18 18 18 16 18 21 21 9 15 Weight (kg) 0.42 0.42 0.42 0.65 0.65 0.65 0.65 0.7 0. [ ... ]