How is a BJT used as an example?
Using a BJT as a Switch: An Example. Remember that the controlled current through a transistor must go between collector and emitter. Since it is the current through the lamp that we want to control, we must position the collector and emitter of our transistor where the two contacts of the switch were.
How does a BJT work in a bipolar junction transistor?
A BJT uses a small current at its base to control a much larger collector current. Before we go any further, it may be useful to define some important terms concerning the operation of a bipolar junction transistor.
How does a BJT work like a closed switch?
Figure 8. An npn BJT operating in the saturation region acts like a closed switch. For a BJT to operate in the saturation region, the base-emitter junction and base-collector junction should be forward-biased, and there should be a sufficient base current to produce the collector saturation current, I C (sat).
Why is the base of a BJT not connected to the base?
In the above figures, the base of either BJT is not connected to a suitable voltage, and no current is flowing through the base. Consequently, the transistor cannot turn on. Perhaps, the simplest thing to do would be to connect a switch between the base and collector wires of the transistor as in figure (a) below.
What are the two types of current gain in BJT?
There are two types of current gain in BJT i.e. α and β. In common base configuration, BJT is used as voltage gain amplifier, where the gain AV is the ratio of output voltage to input voltage: What is NPN Transistor? BJT Construction, Working & Applications
How is the emitter current calculated in BJT?
Construction, Working & Applications It is the ratio of output current i.e. the collector current IC to the input current i.e. the base current IB. The emitter current is the combination of collector & base current. It can be calculated using any of these equations. ICEO is the collector to emitter leakage current (Open base).