homework 4 - bme 302 2010

# homework 4 - bme 302 2010 - Homework 4: BME 302L, Spring...

This preview shows pages 1–3. Sign up to view the full content.

Homework 4: BME 302L, Spring 2010 Due: Tuesday March 23 Preview accepted Tuesday March 9 Problem 1 (10 points): Consider the circuit shown below. It uses a PNP transistor and the mode of bias identified as “voltage divider bias”. Three ammeters and one voltmeter are used to read the values of the transistor currents and the base voltage. 1. Calculate the base voltage V B as the voltage of the voltage divider formed by R 3 and R 4 , that is neglecting the base current of the transistor. 2. Use this value of V B to determine, V E , I E , I C , V C and I B for the circuit. 3. Build the circuit in Multisim and run the simulator. Read with the meters the three currents. Compare with the calculated values, that is determine the % relative error 100*(simulated value-calculated value)/simulated value Determine the transistor beta as I C /I B. Compare the simulated V B to the value calculated in 1. 4. Right click on the transistor. Select on the menu “Properties”, “Edit model” and change the parameter Bf from 180.7 to 300. Then select “Change part model”. Bf is the “ideal” beta parameter for the transistor which is now increased to 300. Run the simulation and compare the transistor currents for the increased Bf to those found for the original value of Bf. Which 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
current is most changed?. Repeat the steps above and lower the value of Bf to 30. Again, run
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/04/2010 for the course BME 302L taught by Professor Maarek during the Spring '08 term at USC.

### Page1 / 4

homework 4 - bme 302 2010 - Homework 4: BME 302L, Spring...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online