Transistor as as switch - replace BC547 with S8050

Collector-Base Voltage
BC547/550 50

Collector-Emitter Voltage
BC547/550 45

Emitter-Base Voltage
BC546/547 5

Collector Current (DC)
100 mA

Collector Power Dissipation
500 mW

DC Current Gain
VCE=5V, IC=2mA 110-800

http://media.nkcelectronics.com/datasheet/s8050.pdf

Collector-Base Voltage V
30

Collector-Emitter Voltage
20

Emitter-Base Voltage
5

Collector Dissipation(Ta=25°)
1 W

Collector Current
Ic 700 mA

DC Current Gain(note)
hFE 110-400

The BC547 is categorized as "designed for use as general purpose amplifiers and switches requiring collector currents to 300 mA."

The S8050 is categorized as "a low voltage high current small signal NPN transistor, designed for Class B push-pull audio amplifier and general purpose applications."