The BS250 is a P Channel enhancement mode vertical D-MOS transistor manufactured in TO-92 package. The pin configuration of the transistor is as follows: The first pin is Source, second pin is Gate and the third pin is Drain.
The IRFI740G is an N-Channel MOSFET from International Rectifier. It has maximum VDSS rated at 10V and can handle continuous drain current up to 5.4A at 150C. The IRFI740G is a 400V 5.4A 40W TO220F Plastic Package 3Pins Power MOSFET.
The HW586 is maximum battery capacity range: 9999Ah (1Ah = 1000mAh) greater value by shifting the decimal point to switch, when the display is less than 10Ah X.XXX, as shown above to achieve 10Ah XX.XX, and so on.
The SI4450DY, SI4450, SI-4450,4 450 is a 60V 7.5A 2.5W This N-Channel MOSFET is produced using Fairchild Semiconductor's advanced Power Trench process that has been especially tailored to minimize on-state resistance & yet maintain superior switching
The C945 is an age old Japanese Bipolar audio frequency NPN transistor 60V 150mA TO-92 package. It has a decent gain value (hfe) of maximum 700 and is highly linear. Hence it was widely used in amplifier.