CAPACITOR CHARGING/DISCHARGING

In this lab we will learn to control the rate at which energy is transferred!

When Vs>Vcap then the circuit is CHARGING

When DISCHARGING, the R(discharge) will absorb the energy.

In THEORY:

Let's build our circuit!

The experiment consisted of one power supply, two resistors, and a capacitor

Let's use our calculations to help us decide values for the devices:

To charge the network it was theoretically said to take 20 seconds

To discharge it was theoretically said to take only 2 seconds

Results

Charging time: 22.27s

Discharging time: 5.15s

Conclusion:

In order to have resulted with better values we should have used different resistors. Part of the error could also be due to old devices, improperly manufactured products, or possibly from human error. One noticeable mistake that occurred was caused by leakage resistance that passed through the capacitor, we ended up with less voltage that may have impacted our data.

IN-CLASS INSTRUCTOR LAB

Below are pictures taken in class while the professor was showing us how signals react when resistors, capacitors, and op-amps are applied.

 The yellow (cosine) curve is the integrated version of the red (sine) function

Frequency sensitivity shows that if the frequency is too low then the op-amp will end up saturating

This is called "damp-oscillation"

 INDUCTOR

A differentiator is not very useful in practice because it amplifies small noises

Use multiple integrators instead!

 CONDUCTOR

Notice the phase shift!

PRACTICAL SIGNAL CONDITIONING

Use temperature sensor LM35 to design an op-amp circuit that will produce

temperature readings in Farehnheit

NOTE: scale factor of 10mV/degree C

Use a scaling and level shifting circuit



A resistance ratio was found with the equation above in order to figure out what values of R1 and R2 were appropriate to use for this experiment:
R1=3kOhm
R2=2.4kOhm
We then continued on to find the reference voltage

(The black component below is an LM35 semiconductor)

NOTE: Because the breadboard that we were using only allowed for two voltage inputs we ended up using a resistance to compensate for the extra voltage that would go into the circuit.

 

We looked online to check if this was an acceptable value.
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Final Circuit (with op-amp):

Vf =  6.59 mV (65.9 degrees Fahrenheit)

Conclusion: To test how accurate our experimented was we calculated % error. It was only about 10% signifying that our results are 90% good.

This was a fun experiment.