5-19: Maximum Power

Today prof Mason  showd us how to determine the power that delivered by AC source.

For this picture,  Professor Mason used  the same voltage for AC power and DC power. The bulb powered by AC source is dimmer than the bulb powered by DC source. 

When professor Mason turns the voltage for AC to about 1.4 times of the DC power, they seems the same bright. The Peak voltage of AC source is about 1.4 which is roughly square root of 2 times the voltage of DC source,

5-28:Signal with Multiple Frequency Component

Today we thought about what happens to circuit elements as the frequency increases.

The graphs show what happens to the impedance of those circuit elements as the frequency is increased.

 The goal of the experiment was to calculate the gain, so the voltage across the resistor was divided by the input signal, and we were left with our formula for our voltage divider. This formula came to be realized as shown below. 

This picture show that the  the gain in the output signal decreases as the frequency increases

The input voltage is a sinusoidal sweep from 100Hz to 10 Khz in 20 msec:

For this lab, we learn about the frequency response of a circuit is determined by the variation in its behavior with change in signal frequency.

5-26: Apparent Power and Power factor

This lab is about power and power factor to quantity the AC power delivered to a load and power dissipated by the process of transmitting this power

This the formula for the power factor. The apparent power is denoted S and it is the product of V rms and I rms. We can also describe the average power as the product of the power factor and the apparent power.

Pre-lab, we used the R2 at different value to get the theoretical values.

Follow the handout, the circuit we build for this lab

The oscilloscope screen with 10 ohm resistor

The oscilloscope screen with 47 ohm resistor.

The oscilloscope screen with 100 ohm resistor

the oscilloscope screen with 10 ohm resistor with a capacitor

the oscilloscope screen with 47 ohm resistor with a capacitor

the oscilloscope screen with 100 ohm resistor with a capacitor

when we add a capacitor in series with resistor. 

For this lab, we learned about apparent power and power factor. and we can  add a capacitor to reduce the phase shift  it could increase the apparent power.