Contents
What is the purpose of a BJT connected as a diode?
The purpose of this activity is to investigate the reverse break down voltage characteristics of the emitter base junction of a bipolar junction transistor (BJT) connected as a diode.
What are the components of a BJT transistor?
The basic construction diagram and symbol of PNP and NPN transistors are as shown in the below figure. The BJT consists of two PN junctions, three layers, and three terminals. Three terminals are Emitter, Base, and Collector. An emitter is used to supply the charge carriers.
Who is the inventor of the bipolar junction transistor?
Hence, a device formed with two junctions, three-layer that is known as Bipolar Junction Transistor or BJT. The BJT was invented by William Shockley in 1948. The bipolar junction transistor allows current to flow by both charge carriers (electrons and holes).
What is the breakdown voltage of a BJT base junction?
In the configuration shown voltages between 0 volts and 10 volts ( W1 peak to peak swing ) can be measured. Capture the scope waveforms and export them into a spreadsheet program such as Excel. For the 2N3906 PNP used in the example, the breakdown voltage of the emitter base junction is around 8.5 volts.
What is the purpose of a fly back diode?
The basic idea behind the use of a Flyback Diode is to provide an alternative path for the inductor for its current to flow. The above image shows the same inductor circuit but with additionally a Flyback Diode. It is important to note that the diode is connected in reverse bias when the switch is closed.
Do You need A flyback diode for a solid state relay?
In any case, there is nothing inductive there, so no inductive kickback to protect against. If the relay is on the same board as whatever is driving it, then no inductive kickback diode is needed. It’s no different than driving any other on-board LED. However, there can be inductance in the circuit from other than the relay.
What happens when a diode is forward biased?
The resistance of the diode, when it is forward biased, is very less and hence the voltage drop across the diode will be significantly less for the current to flow. This prevents arc at the switching device and as a result protects the switching device from damage.