1 files changed, 23 insertions, 0 deletions
diff --git a/147/CH7/EX7.21/Example7_21.sce b/147/CH7/EX7.21/Example7_21.sce
new file mode 100644
index 000000000..07ea5c088
--- /dev/null
+++ b/147/CH7/EX7.21/Example7_21.sce
@@ -0,0 +1,23 @@
+close();
+clear;
+clc;
+//reverse breakdown voltage 'Vz'
+Vz = 8.2; //V
+Rl = 9; //ohm
+vl = 8.2; //V
+Vb = 12; //V
+Vb_max = Vb + 0.1*Vb;
+Vb_min = Vb - 0.1*Vb;
+//75 mA <iz < 1 A
+iz_max = 1; //A
+iz_min = 0.075; //A
+//by ohm's law
+il = Vz/Rl; //A
+//Applying KVL
+Rs = (Vb_max-Vz)/(iz_max+il); //ohm
+//check to see if iz>75 mA at lowest value of Vb
+iz = (Vb_min-Vz)/Rs - il; //mA
+if(iz>iz_min) then 
+  vz = Vz; //V
+end
+mprintf("vz = %0.1f V",vz);
+\ No newline at end of file