Lab 9: Transistors

I began this lab by first forking and then cloning the repository 2012-Physics-308L-Lab-8-Transistors from Dr. Koch. Within the downloaded repository one could find the PDF file for “Lab 4: Transistor Circuits” from Panitz.

Transistors as Diodes

Our first task was to measure the resistance of the different components of the 1N3904 Transistor. A diagram of one can be seen below.

 

 

 

 

 

 

 

 

 

B:C Junction – 2.812 kohm

B:E Junction- 2.957 k ohm

When the leads were reversed the current would not flow and this clearly demonstrated the behavior of transistors as two diodes in series.

Transistors as Switches

For the first day of this lab we simply followed the directions for the part 2 of the Panitz lab 4.

We constructed the following circuit.

 

 

 

 

 

 

 

 

 

 

 

 

An image of this from day one can be found here and an image of the circuit with the addition of the 10 kΩ resistor can be found here.

 

Daq board #121

Issues with several transistors left at station. When constructing the circuit the LED would fail to turn on

board # error

restarted LabView and error no longer occurred.

Initial setup

pic 2: w/ 10k ohm transistor

pic 3: off

pic 4: on

 

Readings

18.17 mA across LED while on (parallel) (incorrect)

10.63 mA ascross LEd while on series Correct

0 mA cross LED while off

current to base.

w/ 10 kohm resistor at A to ground .99 mA

w/ out 10 kohm resistor .50 mA (correct b/c did not need because DAQ board corrects itself)

 

 

 Bad Ass Part

From now on 10 kohm resistor is disconnected

given rise time 35 ns

moved resistor w/ purple 270  to end where emitter goes to ground

red wires channel 2 (e-c)

orange wires channel 1 (switch)

(green to DAQ)

56 ns (within order of magnitude)

270 (pic)

change probe to 1 x andcorresponding in osc

trigger menu

last pic

probe on channel 2 changed from 10x to 1x. Had to lower volts/div but reading that had similar level off was generated.

zoomed in and rise time was anout 36 ns