April 14. Capacitor Voltage-current Relations

Prelab

n this lab we measure the relationship between the voltage and current across a capacitor. To get a better understanding of the relationship we will use three different time-varying signals: sine waves, triangle waves, and square waves as voltages applied to the capacitor. Due to the fact that our measurement tool (Analog Discovery) doesn't measure current we will use the formula:I(c)=C(dv/dt)

We predicted the resulting output based on each input signal below. 

we use a 1uF capacitor with a 100 Ohm resistor in the circuit drawn below.

Below is date for C1(top) A=1.032V across resistor,  C2(under)  A= 1.626V the voltage across the capacitor,  M1(mid)  the current through the resistor,  when f=1kHz, A=2V, and Offset=0V

Below is date for C1(top) A=1.452V the voltage across resistor,  C2(under) A=1.178V the voltage across the capacitor,  M1(mid)  the current through the resistor,  when f=2kHz, A=2V, and Offset=0V

Below is date for C1(top) the  the voltage across resistor,  C2(under)  the voltage across the capacitor,  M1(mid)  the current through the resistor,  when f=100Hz, A=4V, and Offset=0V

Lab Circuit

More practice with inductor. 

Summery
we seeing the relationship between the voltage and current across a capacitor in this lab. We were successful at our analysis that I(c)=C(dv/dt) holds true. We can see as frequency increase the voltage across the capacitor decrease, we will learn why that happens in the future i believe. We also got more experience using the Math Channel to analyze current using Analog Discovery. 
After that, we see the DEMO of inductor lab, unfortunately we don't have time to do it myself.