1 files changed, 27 insertions, 0 deletions
diff --git a/281/CH11/EX11.6/example11_6.sce b/281/CH11/EX11.6/example11_6.sce
new file mode 100755
index 000000000..6242518b1
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+++ b/281/CH11/EX11.6/example11_6.sce
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+disp('chapter 11 ex11.6')
+disp('given')
+disp('design a third order active low-pass filter to have cutoff frequency 30kHz')
+fc=30000
+disp('-20dB per decade stage(first order)')
+disp('select C1=1000pF')
+C1=1000*10^(-12)
+disp('Xc1=R1 at fc/0.65')
+disp('R1=0.65/(2*%pi*fc*C1)')
+R1=0.65/(2*%pi*fc*C1)
+disp('ohms',R1)   //use 3.4kohm+or-1%standard value
+disp('R2=R1=3.4kohm')   //use 3.3kohm standard value
+disp('-40dB per decade stage(second order)')
+disp('select C3=1000pF')
+C3=1000*10^(-12)
+disp('Xc3=sqrt(2)*R4 at fc/0.8')
+disp('R4=0.8/(2*%pi*fc*sqrt(2)*C3)')
+R4=0.8/(2*%pi*fc*sqrt(2)*C3)
+disp('ohms',R4)    //use two 5.9kohm+or-1% parallel-connected
+disp('C2=2*C3')
+C2=2*C3    //standard value
+disp('farads',C2)
+disp('R3=R4=2.95kohm')
+R3=2950
+disp('R5=R4+R3')
+R5=R4+R3
+disp('ohms',R5)   //use 5.6kohm standard value
+\ No newline at end of file