ECE 323L Basic Electronic Circuits Laboratory

Lab 4

 

 

Names:

 

 

 

Do the following exercises. Report your results by editing this Word document and submitting it in WebCT.

 

 

  1. Build another “night light” circuit, this time with a transistor. Use a resistance substitution box from the lab to help choose the resistance R1.   Demonstrate your circuit to the instructor or teaching assistant.

 

 

Measure the resistance of R1 and the voltage VBB at which the transistor begins to turn on (LED begins to glow).

 

 

Resistance

 

VBB

 

 

 

 

  1. Replace the LED with your electric motor and demonstrate that you can control the speed of the motor by the amount of light falling on the photo cell.

 

 

 

 

 

maintained by John Loomis, updated 25 January 2008