- #1

- 1,097

- 3

## Homework Statement

See first figure for lab attachment

## Homework Equations

## The Attempt at a Solution

Hello all,

I recently did a lab on buck converters and I have a couple a questions.

*See the figures attached for lab and my work.*

For

__Experiment 1:__**The measured quantities for part b) were,**

[tex]I_{ave} = 0.2A \quad I_{min} = 0.09A \quad I_{max} = 0.28A \quad Ripple_{pp} = 0.19A[/tex]

These values differ slightly from my theoretical calculated values, did I make any mistakes or are there any discrepancies?

Also, the Imin I calculated was negative, is this a problem? Also, I'm not sure if I am correctly the average current correctly, can someone verify?

**The new switching frequency we measured for part c) was,**

[tex]f_{swnew} = 300Hz[/tex]

The theoretical frequency I calculated was 240Hz. Is this a large discrepency? Did I make any mistakes in the calculation?

For

__Experiment 2:__

**For part a),**

**The measured quantities for 500 rpm are,**

[tex]V_{t} = 32.8V \quad I_{a} = 0.82A \quad \text{Duty cycle }= 32.8\%[/tex]

**The measured quantities for 1000 rpm are,**

[tex]V_{t} = 59.81V \quad I_{a} = 0.89A \quad \text{Duty cycle}= 59.81\%[/tex]

**The measured quantities for part c) are,**

[tex]I_{ripple,p-p} = 1.27A \quad I_{ripple,avg} = 0.79A \quad f = 292.51Hz \quad \text{Duty cycle }=32.09%[/tex]

When we preformed this we did not observe any oscillations on the shaft speed but I'm not quite sure why.Is it simply because the switching frequency was high enough such that the motor wouldn't have time to react to any of the sudden changes in voltage?

Can someone clarify why that would be the case?

Thanks again!