Summing Amplifier

Summing Amplifier

In this lab, we calculate the three resistors and set up a Summing Amplifier Circuit in order to record the amount of Vout. This output voltage will be measured by adjusting Va. 

From the picture below, we calculated that the three resistors will have the same resistance of 2.2KΩ. 

Then after measuring the three resistors, we got the actual amount of resistance and then we set up the circuit as shown below: 

Once the circuit is set up, we then adjust the Va voltage to find the output voltage. As shown below, Vb is a constant 1: 

Inverting Voltage Amplifier

Inverting Voltage Amplifier

In this lab, we designed an inverting Voltage Amplifier circuit using two resistors and an OP 27. This circuit is designed to provide a gain of 2.2 with an input resistor of approximately 2.2 KΩ. To obtain the resistance of R2, it is calculated using the equation:

Gain = R2/R1. Then, we get that the resistance of R2 should be 4.7KΩ. 

In this picture, the actual schematic of the circuit is shown with the actual measurements of the resistance. 

Once the circuit has been set up, we measure the gain from the amplifier of the OP27 and saw that it has close to the gain of 2.2. Then, we measure the amount of output voltage given depending on how much input voltage we put in as shown on the picture below: 

From the fact that our actual gain is very close to the expected gain, there might only be a very small amount of saturation. 

During lecture, we learned about how to calculate gain from the circuit. Then, we also discussed about how to draw the output voltage graph as shown below: 

Summary

For this lecture, we learned about calculating gain and making the output voltage graph. In lab, we design an inverting voltage amplifier and calculate the resistance needed to obtain a gain of 2.2. What we got from making the circuit was a gain of 2.19 after calculating the resistance of the second resistor. 

Superposition

Superposition

In the lecture, we talk about super position and how this method can be better used over mesh analysis. As shown in the picture below, one circuit is solved using mesh analysis and the other is solved using superposition.  

Circuit solved using mesh analysis

 Solved using Superposition

For the lab, we predict the voltage of the circuit shown:

Then we record the actual resistance of the resistors we got and made the schematic for it: 

Next, we set up the circuit and record the resulting voltage across the 6.8k resistors: 

With only the 3V source:

 With only the 5V source:

With both sources:

Using the data above, we calculate the percent difference between the calculated sum of voltages of the independent 5V and 3V source and compared it to the measured one: 

[(2.685-2.69)/2.69]*100% = 0.19% difference. 

Here is the table of the analysis and experimental results: 

Summary:

We learn about a new method called the superposition where it's a method used for the circuits. It can be shown to be better to use than the mesh analysis. In the lab, we use superposition to find the voltage across the 6.8 KΩ.

Mesh Analysis 2 and Time Varying Signals

Mesh Analysis 2

In this lab, we predict what the current I₁ and V₁ for what this circuit will be.

And doing the calculations as shown below:

 We get that:

I₁= -3.2mA

V₁= 5.0184V

After predicting the current and voltage, we collect the resistors and record the actual resistance as shown below:

Thus, taken from the picture, (Except for the 10KΩ is exactly as measured), the circuit for the actual resistors are drawn as shown below: 

After measuring the current I₁ and voltage V₁ and V₂  we get the data below:

Current I₁

% error:  0.9375%

:

 voltage V2

 Voltage V1

% error: 0.964%

For the lecture, mesh analysis is used here in order to find I_B,I_C, and V_o. Thus, by doing the calculations below: 

We get that:

I_B:  .165mA

I_C: 8.25 mA

V_o: 5.175

After the lecture, we went test the response of the circuits by having images of the input and output voltage sketches: 

Summary

In conclusion, we use mesh analysis to find the hidden current and voltage and apply those calculations onto the lecture and the lab. We record the actual measurements and then measured the voltage and current to get the % error between the predicted data and the actual data. Then we also did mesh analysis to find the currents and voltage involving a transistor current. Afterwards, we use the waveform programs to see varying oscillation responses from the circuit. 

Nodal and Mesh Analysis

Nodal and Mesh Analysis 

In this lab, we use the breadboard to set up the circuit and then we calculate V1 and V2 as shown in the picture below:

Using nodal analysis, we find from the picture above, we find the voltage of the node along with V1 and V2 {Voltages of the 22kΩ and 6.8kΩ resistor}. 

Once we calculated V1 and V2, we then proceed to set up the circuit and then record and measure V1 and V2 as shown below: 

Then calculating the % error for V1 and V2: 

The reason the recording shows positive is because we placed the red and black alligator clips at the opposite ends of the sides. The difference for V2 seems quite large. This may be because the voltage provided is not as much as we calculated.

For the lecture, we learned about mesh analysis and how it's applied to circuits: 

In the picture above, we find out what are the currents i1 and i2. To do so, we use mesh analysis which involves the equation around the first loop and second loop using the sum and difference of the voltages of the resistor or the battery supply. For the 20Ω resistor, we use i1-i2 for the first loop and i2-i1 for the second loop as current for the 20Ω resistor. 

This picture involves the same thing as the previous picture. The equation was set up based around the three loops. With this, we may use matlab to find the currents of the first, second, and third loop. 

Summary

In the lab, we use node analysis to calculate the voltage. Then in lab, we set up the circuit and record the voltage. Afterwards in lecture, the professor taught us mesh analysis which involves finding either current, resistance, or voltage. 

Temperature Measurement System

Temperature Measurement System

In the lab, we design a temperature measurement system with a termistor, a resistor, Vout Voltage, and the 5V power supply. Before doing the lab, we determine Vout as a function of Rth and R. 

From this Picture, Vout is calculated. Then we verify if the Vout temperature increases as temperature increases and by using the quadratic formula in the picture above, it is confirmed that it does. 

When the circuit was set up. We check to see the resistance at room temperature and watch what happens as temperature increases:

From the picture it is shown that as temperature increases (As I touch the Thermistor) the resistance Rth decreases. 

Now we record the voltage of the circuit from when it is at room temperature and from when I touch the thermistor. 

From the picture shown, Voltage increases as temperature increases. when I was taking the picture as I'm touching the thermistor, the Voltage kept increasing. 

From the calculated Voltage: 

10.95kΩ would be calculated to 2.39 V

6.39 kΩ woudl be calculated as 3.05V. 

Doing the % error: 

1.3% error for the 10.95kΩ

and

2.3% error for the 6.39kΩ

At the lecture, we learn about the nodal analysis and how the method was used.

On this problem, we need to calculate the node voltage on the circuit: 

Using KCL and Ohm's law, we get that: 

V1 = 13.33V

and

V2 = 20V

Summary

In the lab, we record the voltage of the thermistor.  After recording the voltage which is at room temperature, we touch the thermistor to record the voltage. When we touch the thermistor, it increases temperature which also increases the voltage. This is because as temperature increases, the resistance decreases.