HW3a: Power Supply LTspice Design a resistor/LED circuit such that the diode will be brightly let when Vout is 5 volts. Assume the diode has a forward voltage of 3.65V and a forward current of 20mA, when the diode is brightly emitting light. Note: You need to round your resistors to a whole number, as you cannot purchase non-whole numbers resistors. Include:     Show how you calculated R3 to meet specification. Show modified schematic of circuit showing your name and the R3 value you designed. (Include caption.) Show simulation results. (Include caption.) Explain why the theoretical results did not match the spice results. (Best to include a comparison table.) Guidelines/Hints: Demonstrate your results with LTspice. This assignment has to be done in a professional format. No handwritten notes. Do not use X,x,*,^ or such symbols for multiply or exponents. Plagiarism: Using a modified version of my LTspice file is not plagiarism. Cutting and pasting my figures or equations is. You can of course use: 𝑅 𝑉𝑜𝑢𝑡 = 𝑉𝑟𝑒𝑓 × (1 + 𝑅2 ) because it is from the data sheet, but you have to enter it in the word 1 processing program of your choice. Figure 1: 5 Volt regulated DC power supply powered by a 9V battery using a LT1086H, with an LED based power indication system. Here is a link to the spice file to get started. This is a practice for your final project report, so all the work must be documented in a word processing program like word. Equations must be done in equation editor for instance: 𝑅 300Ω 𝑉𝑜𝑢𝑡 = 𝑉𝑟𝑒𝑓 × (1 + 𝑅2 ) = 1.25𝑉 × (1 + 100Ω) = 5𝑉 (1) 1 is acceptable. 𝑅 300Ω 𝑉𝑜𝑢𝑡 = 1.25𝑉𝑥 (1 + 𝑅2 ) = 1.25𝑉 ∗ (1 + 100Ω) = 5𝑉 1 is not. You can start with the sample file provided. Results: Figure 2: : Results of .op spice simulation of the output voltage of an LDO 5 volt power supply and a LED brightly light with approximately 20mA current. This figure needs to be improved by highlighting the relevant measurements. Figure 3: : Results of .op spice simulation of the output voltage of an LDO 5 volt power supply and a LED brightly light with approximately 20mA current. OR Table 1: Results of .op spice simulation of the output voltage of an LDO 5 volt power supply and a LED brightly light with approximately 20mA current. V(out): I(D1): 4.98256 0.0199696 voltage device_current Analysis of results: Compare your hand calculations to LTspice. A table is best. LTspice Measured Vout (V) Theoretical Results 5 4.98 ID (mA) 20 19.96 Final Report Final Report Explain differences in theory vs. LTspice. Possible reasons:    R3 was rounded up or down to a whole number thus changing: 𝑉𝑜𝑢𝑡 − 𝑉𝐹 𝐼𝐷 = 𝑅3 Vout was not exactly 5V due to 50A leakage current into adjust pin. (See data sheet.) Vref is not exactly 1.25V. Vref does shift form device to device and with temperature. You can measure this in LTspice Subtract Vout from the adjust node and you will see it is not exactly 1.25V BTW: These differences are masked by the tolerances of the resistors you will use in the final circuit (10%.) HW3b: Diode Applications These problems need to be submitted as one pdf. Scanned handwritten notes are fine, but must be legible. You do not have to use equation editor. Question 1 (10pts): The circuit below does not give 5 volts on Vout as expected. Explain what I have done wrong. To find out what I have done wrong you have to read the data sheet and check to make sure I have se the circuit up properly. Of course the first thing to check in to see if R1 and R2 are correct. This kind of problem in which you have to de-bug a circuit that you have little experience with by reading the datasheet is a realistic exercise. To see if your solution to the problem is correct, down load the circuit in LTspice, fix the problem and run the simulation and see if the problem has been resolved. You do not have to include your LTspice results. No “fancy” documentation required. The data sheet can be found here: http://cds.linear.com/docs/en/datasheet/1086ffs.pdf The spice file is here. Question 2(10pts): A protection diode was added to the power supply circuit to prevent damage to the circuit if the battery was accidentally plugged in backwards. The circuit below does not give 5 volts on Vout as expected. Why? The data sheet can be found here: http://cds.linear.com/docs/en/datasheet/1086ffs.pdf To see if your solution to the problem is correct, down load the circuit in LTspice, fix the problem and run the simulation and see if the problem has been resolved. You do not have to include your LTspice results. No “fancy” documentation required. The spice file is here. Question 3(5pts): Draw the voltage of Node a2, and the current though R1 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Question 4(5pts): Draw the voltage of Node b2, and the current though R2 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Question 5(5pts): Draw the voltage of Node c2, and the current though R3 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Assume any diode model. Question 6(5pts): Draw the voltage of Node d2, and the current though R4 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Question 7(5pts): Draw the voltage of Node e2, and the current though R5 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Question 8(5pts): Draw the voltage of Node f2, and the current though R5 on the graph below. Assume any diode model. You can use LTspice to verify your results, but it not required. Show your calculations. Check your work!: The spice file is here. Question 9(10pts): Design V1 and R1 to bias the LED’s so that they are brightly lit. VF=3.4V and IF=10mA when the LEDs are brightly lit. There is only one equation but two unknowns. You have to choose a “reasonable” value of V1 to get a “reasonable” (R1>50Ω).