BD140 – 80V ,1.5A NPN power Transistor voltage regulator

BC547 is a general purpose BJT NPN transistor mostly used in electronics hobbyists and educational electronics projects. Besides these uses it can also be used in commercial circuits. It comes in TO-92 packaging and the maximum output current this transistor can handle is 100mA. The transistor is having very good DC current gain and low noise capabilities due to which it is ideal to use in signal amplification stages. The typical saturation voltage is only 90 millivolts which is also a good sign to use it as a switch.

BC548 is another general purpose widely used transistor that can be easily get from reputable electronic components store, this transistor also have bunch of good features on the basis of which one can use it in their electronic circuit, it can handle maximum current of 500mA which is enough to drive many other components such as ICS, other transistors, portion of a circuits, relays, LEDs etc. The max collector dissipation of the device is 625 miliWatt which is another good feature to use it as a small amplifier.