3/16 Nodal Analysis Multiple Sources

        The purpose of this lab is to verify the node analysis. We need to find the theoretical value of current then compare to the actual current in the circuit. Then find the percent error.

1.In the space below, provide a schematic of the circuit, labeled with reference node and values for node voltages as determined in the pre-lab. Provide estimates for the voltages V1 and V2 , based on your node voltages.

Based on our calculation: V1 = 2.424V and V2 = 4.424V

2. In the space below, provide a schematic of the circuit being testing, including measure resistance values.

The test resistance is 1.66K

3. Provide your measured values for the voltages V1 and V2. Provide a percent error between the measured and expected values of V1 and V2. Comment on any significant differences between the measured and expected values.

Measured value: V1 = 2.37V, V2 = 4.34V

percemt error: V1 = 2.22%  V2 = 1.90%

Summary

      In today's class, we learned how to use the node analysis. In each node, the amount of current follow in and out have to be the same.

3/9 Temperature Measurement System

        The purpose of this lab is to observe the resistance change when the temperature changes.

1. Provide:
      a:

based on the calculation we did on the white board, the resistance should between 4367 and 17633. Therefor, we choose the medium value 10K.

     b.: according to those formula, when R = 10K the change of voltage should be 0.6337V.

     c: We except that when we increase the temperature, the voltage should also increase.

2. Rth at room temperature R = 9.9k

    Rth at 37, R = 5.9k

3. The actual value of R is 9.8K

4.Measurement: 

5.

     a. when we increase the temperature from room temperature to 37, the voltage increase from                     2.46V to 3.09V. Therefore, the output voltage increase as temperature increase.

     b. the change of voltage is 3.09V - 2.46V = 0.63V.

         the change of temperature is 37 - 25 = 12

         0.63/12 = 0.0525

         In this case, our design meet the design requirements.

Summary

       In today's class, we learned the basic concept of resistance. We learned that the resistance of thermistors will change if the temperature changes. Then, we did a experiment with the thermistors

3/7 Dusk-to-Dawn Light

                 The purpose of this lab to observe the behavior of photocell and learned the change of resistance due to the change of temperature.
1. Provide the calculated values of Vb for photocell resistance of 5K and 20K

2.Provide measured values of Vb for photocell resistance of 5k and 20 K and comparison with calculated values.

percent error for 5K = (1.67-1.67)/1.67 * 100% = 0%

percent error for 20K = (2.9-3.33)/3.33 * 100% = -12.91%

3. A video of the circuit operating:

Summary

          In today's class, we learned the concept of parallel and series resistance. We did some examples of how to calculate the equivalent resistance for the parallel and series resistance. The following photos are the examples we did during the lecture time.

     Also, we observed the phenomenon of the value of resistance changes with the temperature changes which is our experimental today.

                                                             

Summary

          In today's class, we learned the definition of a resistance. And the theoretical equation of how to calculate the resistance. Then, we learned a new types of resistance-photocell which is a resistance that the value will change response to the environment temperature.

3/2 Dependent Sources and MOSFETs

         The purpose of this lab is to observe how the dependent sources circuit work and determine what types of dependent sources is this.

1. Diagram of circuit:
    This photo shows that we measured the value of resistance.

This photo shows how we connect the entire circuit.

According to all the data we got from the measurement, we have this graph that shows the relationship between current and voltage.

Based on the graph, we found that the MOSFET threshold voltage is  around 0.68 V.

4. This is a dependent source because when we increase the value of voltage, the value of current also increases. Therefore, this is a depend source.

5.

According to this graph, the value of g is 0.8923.

Summary

      In today's class, we learned the concept of KCL and KVL circuit. The key point of KCL circuit is that the total current through one node have to be 0. The same as the KVL which is the total voltage through one node has to be 0. The following photos are some examples we did during the lecture time:

2/28 Solderless Breadboards, Open-circuits and Short-circuits

      The purpose of this lab is to observe how the breadboard works and have a better understand of actual circuit. Prepare for the future lab.

1. Provide the resistance you measured between two holes in same row. State whether these operate as open or closed circuit.

According to this photo. The value of DMM is 0.6 which means this is a closed circuit.

2. Provide the resistance you measured between two holes opposite sides of channel. Characterize as open or closed circuit.

According to this photo. The value on DMM is 1 which means this is a open circuit.

3. Provide the resistance you measured between two arbitrary holes in the breadboard. Characterize as open or closed circuit.

According to this photo. The value on DMM is 1 which means this is a open circuit.

4.Provide the resistance you measured between holes connected by a jumper wire. Characterize as open or closed circuit.

According to this photo. The value on DMM is 011 which means this is a closed circuit.

Summary

        In today's class we learned the basic ideas about the circuit: the open circuit and closed circuit. The basic requirement for a circuit to work properly. We also did some examples that how to calculate the resistance, voltage and current.