LEARN MORE...

Week 6 Test

Content type

User Generated

Subject

Engineering

Type

Homework

Uploaded By

Ovfuynz R

Pages

Showing Page:

1/5



1.                   

 !

"###$



#

#%&#$



(  )              *  &  

%



%



+





            &  -  



+!.    #/



   #0.  

##/







#+2#0.3,%



#+2!.3,%



4*&+52#6/7.3%



+8%1

%



+52#6/7.3



,8

 #/



0.



*#80%#%09





2. 7(

5#%5

0(       4&&       

0##!#%

(-:+%

)



/

)

1



)



/:+6/#0+.





1

Showing Page:

2/5

+#/##0+7#.

&&#%&7#.)



551&*







+

)

%



+%

)

1

/



+2/3,2/3,;;,2/3+/





+/

      -%



 1



+%

       +%



/%+%

)

/%+6/#+<#        

+/



+/

)

      +2<#3=27#3/+87&+6&6



      <#(



                         





3. #>

<71(&5

15&15>

&91-

0

?&@



(+,)2A3



+#

,<02#

3



+688

Showing Page:

3/5

End of Preview - Want to read all 5 pages?

Access Now

Unformatted Attachment Preview

Week 6 Test 1. Reference the textbook problem 6.12. Design a system using the photoconductive cell in Figure 6.9 to measure and display light intensity. Make the design such that 20 to 100 mW/cm2?produces an output of 0.2 to 1.0 V. What is the readout error when the intensity is 60 mW/cm2? Ans Let ignore the nonlinearity of graph then equation between cell resistance and Vout Vout = mRc+Vo From the graph we find Rc=2.9k? at 20mW/cm2 and 0.5k? at 100mW/cm2, so 1.0=m(0.5k?) + Vo 0.2=m(2.9k?)+ Vo Solving these equations we have m=-(0.8/2.4 k?) and Vo=1.1667V, so Vout = - (0.8/2.4 k?)Rc+1.1667 From the graph for an intensity of 60mW/cm2 the resistance is 1.25k?.The above equation gives the result 0.75V but it should be 0.6V.The 25% error is due to strong nonlinearity of cell resistance versus intensity. 2. Reference the textbook problem 6.14. A single silicon photovoltaic cell is found to have an open-circuit voltage of 0.6 V and a short-circuit current of 15 mA in full sunlight. Show how a collection of these cells can be arranged to deliver 500mW at 9.0V into a load. Write a verbal description Ans We find the load resistance from P=VL2/RL, so RL=VL2/P=81/0.5=162? The cell internal resistance is found from open circuit voltage and short circuit current, so R=0.6/0.015=40? Then we model each cell with 0.6V source in series ...
Purchase document to see full attachment