appears across the transistor collector-emitter terminals. The BJT is "saturated" if IC reaches its maximum value along the load line (IB > 100 μA). Therefore, the transistor can be operated as an OFF switch with IB = 0 μA and as an ON switch with IB = 100 μA. To operate the BJT as an amplifier, it is necessary to set the operating point in the Every modern piece of audio circuitry has transistors at its heart amplifying signals. A transistor will act linearly if the base-emitter current is within a specified range (depending on the model of transistor). That means that the collector-emitter current will be some multiple of the base-emitter current. Experiment 3 The Transistor Objectives 1. Measure the characteristics of an emitter follower circuit. 2. Construct and analyze a voltage regulator circuit for a solar panel. Equipment 1. 1 2N2222 NPN bipolar transistor 3. Multimeter 4. Topward power supply 5. 2 - 2.2 k and 1 - 1 k resistors 6. Breadboard 7. 12 volt - 5-Watt zener diode 8. behind a transistor allows it to act as an amplifier of electronic signals or as a switch for signals and electrical power (Mims, 1990). Take note that both operational purposes of a transistor, specifically as an amplifier and as a switch, were originally reserved only for electron vacuum tubes. A transistor operates better than vacuum This is called TRANSISTOR ACTION and is the single most outstanding property of transistors. The above argument makes it intuitively clear that the emitter current is greater than the base current (also see equation #3 below). A property of transistors is that the ratio b = Ic Ib is always a constant regardless of the size of Icor Ib.