# Lab 13: Diodes

Lab 13 will come from the published version of the lab manual.

## Suggested Pre-Lab Activities

Completing the following activities before attending lab will save you time during the lab session.

• none

## Lab Manual Errata

The following are known errors in the lab manual corresponding to lab 13.

• The circuit 4 schematic is incorrect, see the figure below for the updated schematic. The text should read: Pushbuttons A and B correspond to the inputs. The 100 ohm resistors are pull-down resistors. The 1 kohm resistor is part of the diode-resistor logic. The 220 ohm resistor limits the current through the output LED. Circuit diagram for circuit 4 (diode resistor logic gate) in lab 13.

## Lab Modifications

The following parts of lab 13 have been modified from the published version of the lab manual.

• After completing lab 13, you will complete an activity to prepare for lab 14.
• Download the data sets for each mystery box (posted on Blackboard) to open in LoggerPro.
• After opening the file(s) in LoggerPro, select the data set, then click on the button for curve fit. Select cosine A*cos(Bt+C)+D, then click on Try Fit, then click on OK. Complete these two steps for both the voltage and the current graph.
• Read the data from the curve equation off of the graph. This will provide you with the amplitude and phase of each wave. Convert the phase from radians to degrees. Record the current and voltage in your updated version of lab 14. (It will be different than what’s in the lab manual.)
• Now that you know voltage and current, you can calculate the impedance; the resistance is the real part and either inductance or capacitance can be calculated from the imaginary part. Record this in lab 14.
• Use the inventory of parts to determine which of the component values (resistor / capacitor / inductor) was likely used. You can assume the parasitic resistance of any inductor is approximately 50 Ohms.
• To save time before lab 14, you may want to calculate the compensation circuit required to increase the power factor of the circuit to one.
• Repeat the previous steps for both mystery boxes.
• The schematic below shows the mystery box arrangement. It is different than what’s printed in your lab manual. Circuit diagram of how the lab 14 mystery box circuits were measured to obtain voltage and current.

## Resources

Watch/read the following resources prior to attending this lab. This information will teach you how to use lab equipment and provide suggestions and technical tips for successfully completing the lab.