Nate Robinson
Professor Kinley
EET-115 Lab 4 Write Up
October 9, 2014

Part 1 In part 1 of the lab, I constructed this circuit on my protoboard.

Once I had the circuit set up correctly, I set up a truth table showing the inputs and output for the designated inputs. Shown here is the truth table: D | C | B | A | X | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 |

To figure out what the output would be (X) I had to Demorganize the circuit equation to make it simpler to work with. When I simplified the equation, I ended up with an equation the represented a 3-input OR gate. In order to test and make sure that this was valid, I checked the logic level of the output with my logic probe. Based on the truth table, we can conclude that as long as one of the inputs is a logic level 1, the output will also be a logic level 1.

Part 2

In part 2 of the lab, I constructed an additional circuit on my protoboard that looked like this:

Once this circuit was constructed, I Connected the Function Generator to input A, and Connect CH1 of the Oscilloscope to input A and CH2 to the Output. Then, I set the function generator for a 1KHz square wave. Once that was done, I proceeded to answer question one, which stated: Determine which edge (rising or falling) of the input A corresponds to an edge (rising or falling) of the Output. I said: The Rising edge of input A matches up with rising edge of output. For question 2, I was to measure any time delay between the two edges. I also was to answer the question of whether or not there should be any delay. Here is what I said:

The delay is 20 ns. There should be a bit of delay because it takes time for the chip to recognize a change from input/output.

Part 3

For part 3 of the lab, I was required to allow Mr. Kinley to put a fault in my circuit from Part 1. After closely examining my circuit, I found that there was no solid connection from my ground bus to my ground lead wire because the metal tip had been snipped off. Because of this fault, I was not getting the outputs that I had expected to get.