TRANSISTOR SWITCHING

In this experiment we begin to discover how a transistor works. To begin we will begin by assembling a circuit like this.

 

 

 

 

 

 

after turning the led on, we then begin to remove the led and rebuild the circuit but this time with a potentiometer and two ammeters in order to measure the current of the base and the I of the emitter.

 

 

 

 

 

 

 

here is a table of our measurements, our measurements  are not exactly how the experiment required due to the range of our potentiometer. this small range of our potentiometer resulted in a deficiency of not being able to find saturation of the transistor.

 

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Milliamps passing through A1 Base current	Milliamps passing through A2
0.131	0.777
0.151	0.916
0.171	1.045
0.191	1.181
0.211	1.32
0.231	1.482
0.251	1.585
0.272	1.727
0.294	1.879

 Here is a graph of the measurements  with the rages that we could measure

 

 Here is a calculation of the Beta (gain) of the transistor. which is the slope of our graph shown above.

 

 

 

 

In conclusion we have found out that the transistor acts as a variable resistor and amplifier. the transistor acts as a variable resistor because as you add current trough the base there is less resistance and therefore the current through the emitter increases. the transistor also acts a an amplifier because even when putting our finger in the circuit, the led still had enough current to be turned on.