The DS1302Z is a trickle-charge timekeeping chip contains a real-time clock/calendar and 31 bytes of static RAM. It communicates with a microprocessor via a simple serial interface IC SOP-8 Pins Package.
The TIP42C is a base island technology PNP power transistor in TO-220 plastic package that make this device suitable for audio, power linear and switching applications. The complementary NPN type is TIP41C.
The 2N5551 TO-92 NPN High Voltage Transistor 160V 0.6A. NPN high-voltage transistor in a TO-92; SOT54 plastic package. PNP complements: 2N5400 and 2N5401.