# 8.5: Procedure


## 1.5.1: RL Circuit

1. Using Figure 1.4.1 with E = 10 V, R = 47 k$$\Omega$$, and L = 10 mH, calculate the time constant and record it in Table 1.6.1. Also, calculate and record the expected steady state inductor voltage in Table 1.6.2.

2. Set the power supply to 10 V but do not hook it up to the remainder of the circuit. After connecting the resistor and inductor, connect the DMM across the inductor set to read DC voltage (20 volt scale).

3. Connect the power supply to the circuit. The circuit should reach steady state very quickly, in much less than one second. Record the experimental inductor voltage in Table 1.6.2. Also, compute and record the percent deviation between experimental and theory in Table 1.6.2.

## 1.5.2: RC Circuit

4. Using Figure 1.4.2 with E = 10 V, R1 = 47 k$$\Omega$$, R2 = 10k and C = 1 $$\mu$$F, calculate the time constant and record it in Table 1.6.3. Also, calculate and record the expected steady state capacitor voltage in Table 1.6.4.

5. Set the power supply to 10 V but do not hook it up to the remainder of the circuit. After connecting the resistors and capacitor, connect the DMM across the capacitor set to read DC voltage (20 volt scale).

6. Connect the power supply to the circuit. The circuit should reach steady state quickly, in under one second. Record the experimental capacitor voltage in Table 1.6.4. Also, compute and record the percent deviation between experimental and theory in Table 1.6.4.

## 1.5.3: RC Circuit (long time constant)

7. Using Figure 1.4.2 with E = 10 V, R1 = 47k, R2 = 10 k$$\Omega$$ and C = 470 $$\mu$$F, calculate the time constants and record them in Table 1.6.5. Also, calculate and record the expected steady state capacitor voltage (charge phase) in Table 1.6.5.

8. Set the power supply to standby, and after waiting a moment for the capacitor to discharge, remove the capacitor and replace it with the 470 $$\mu$$F. Connect the DMM across the capacitor set to read DC voltage (20 volt scale).

9. Energize the circuit and record the capacitor voltage every 10 seconds as shown in Table 1.6.6. This is the charge phase.

10. Disconnect the power supply from the circuit and record the capacitor voltage every 10 seconds as shown in Table 1.6.7. This is the discharge phase.

11. Using the data from Tables 1.6.6 and 1.6.7, create two plots of capacitor voltage versus time and compare them to the theoretical plots found in the text.

8.5: Procedure is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by James M. Fiore.