7.6: Procedure


7.6.1: Series-Series Voltage-to-Current Transducer

1. The transconductance of the voltage-to-current transducer can be determined from $$R_i$$. Based on the $$R_i$$ values, calculate the expected $$I_{load}$$ for the circuit of Figure 7.5.1, and record them in Table 7.7.1.

2. Assemble the circuit of Figure 7.5.1 using $$R_i$$ = 1k $$\Omega$$ and $$R_{load}$$ = 100 $$\Omega$$.

3. Set the generator to a 100 Hz sine wave, 1 volt peak.

4. Apply the generator to the amplifier. Measure and record the load current in Table 7.7.1. Also, compute the resulting theoretical versus experimental deviation.

5. Repeat step 4 for the remaining $$R_i$$ values in Table 7.7.1.

6. Since the circuit behaves as a constant current source, the value of the load resistance should have no effect on the load current (within normal parameters). To verify this, change $$R_{load}$$ to 1k $$\Omega$$ and repeat steps 4 and 5, using Table 7.7.2.

7.6.2: Parallel-Series Current Amplifier

7. The gain of the current amplifier can be determined from $$R_i$$ and $$R_f$$. Based on these values, calculate the expected $$A_i$$ and $$I_{load}$$ for the circuit of Figure 7.5.2, and record them in Table 7.7.3.

8. Assemble the circuit of Figure 7.5.2 using 22k $$\Omega$$ for $$R_f$$.

9. Set the generator to a 100 Hz sine wave, 1 volt peak. Note that the 10k $$\Omega$$ resistor at the input serves to convert the voltage from the generator into a current. With the values specified, the input current should be approximately 100 microamps.

10. Apply the generator to the amplifier. Measure and record the load current in Table 7.7.3. Also, compute the resulting current deviation.

11. Repeat step 10 for the remaining $$R_f$$ values in Table 7.7.3.

7.6.3: Troubleshooting

12. Utilizing the circuit of Figure 7.5.2, suppose that all of the results found in Table 7.7.3 are approximately 10 times smaller than they should be. Consider and test at least two plausible causes for this scenario, and include the results in the technical report.

This page titled 7.6: Procedure is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James M. Fiore via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.