ENGR 2255 - Lab #10

Title: 

RL Circuits

Objectives: 

• Design and test an RL circuit
• Gain further experience using the oscilliscope to analyze time varying circuits

Preparation: 

1. Calculate the time constant for the RL circuit below.
2. Use PSpice to perform a transient analysis of the circuit. Use Probe to plot Vo when Vi is:
   1. a 0 V to 10 V squarewave with a frequency of 100 Hz.
   2. a 0 V to 10 V squarewave with a frequency of 1 kHz.
   3. a 0 V to 10 V squarewave with a frequency of 10 kHz.

Equipment and Parts: 

• Prototyping board
• Signal Generator
• Oscilliscope
• Resistor: 200 Ω
• Inductor:  47 mH

Procedure: 

1. Create the RL circuit from the preparation on a proto board.  Record measured resistor value.
2. Observe Vo on the oscilliscope with a 0 V to 10 V squarewave input signal of 100 Hz.  Draw Vo versus Vi in your lab book.
3. Measure the time constant on the oscilliscope.
4. Calculate the inductance of the inductor from the time constant and resistance measurements.
5. Change the input signal frequency to 1 kHz.  Observe and record Vo.
6. Repeat for an input signal frequency of 10 kHz.

Conclusions: 

• Compare the observed/measured waveforms and time constants with the PSpice simulations.  Suggest possible reasons for any discrepancies.
• Discuss how well the objectives were met.