In the circuit consider that the current minimum for Z1 and Z2 operate in the zener is 5 mA range V = 0.7V amd PZ2 = 0.8 V
a) Calculate the values of R1 and R2 knowing that the current travels through the diode Z1 and 30 mA, and the current that runs trough Z2 is 15 mA
b) Determine the maximum voltage that is possible to use in Vsupply without damaging the Zener diodes
c) Determine the voltage to the extremes of the resistance of 5000 Ohm when Vsupply = 5 V
a)For this i have done the following meshes:
\(
25 V=R1*Iz1-10 V
R1=(35)/(30mA)
R1=1,16 kOhm \)
For determing R2
\(
25 V=R1*Iz1+(R2//1k)*Iz1+500(Iz1+Iz2)
25 V=1.2kohm*30mA+(R2//1k)*30mA+500(30mA+15mA)\)
This is giving me a negative value for the resistor R2,so i must be doing something wrong.
b)I know that Vz1=Vz2=0.8 W
\(
Pz1=Vz1*Iz1
0.8 W=10V*Iz1
Iz1max=80mA
Pz2=Vz2*Iz2
0.8 W=5 V*Iz2
Iz2max=160 mA
\)
\(
Vsupply=R1*Iz1max+R2+(R2//1k)*Iz1max+500(Iz1max+Iz2max)
\)
Is this the correct way to determine the maximum value for Vsupply?
Since i don't know R2 i can't determine this
c)When Vsupply=5 V
The zener Z2 will be inversely polarized and so V 500 Ohm=5 V
Is this correct?
Thanks
a) Calculate the values of R1 and R2 knowing that the current travels through the diode Z1 and 30 mA, and the current that runs trough Z2 is 15 mA
b) Determine the maximum voltage that is possible to use in Vsupply without damaging the Zener diodes
c) Determine the voltage to the extremes of the resistance of 5000 Ohm when Vsupply = 5 V
a)For this i have done the following meshes:
\(
25 V=R1*Iz1-10 V
R1=(35)/(30mA)
R1=1,16 kOhm \)
For determing R2
\(
25 V=R1*Iz1+(R2//1k)*Iz1+500(Iz1+Iz2)
25 V=1.2kohm*30mA+(R2//1k)*30mA+500(30mA+15mA)\)
This is giving me a negative value for the resistor R2,so i must be doing something wrong.
b)I know that Vz1=Vz2=0.8 W
\(
Pz1=Vz1*Iz1
0.8 W=10V*Iz1
Iz1max=80mA
Pz2=Vz2*Iz2
0.8 W=5 V*Iz2
Iz2max=160 mA
\)
\(
Vsupply=R1*Iz1max+R2+(R2//1k)*Iz1max+500(Iz1max+Iz2max)
\)
Is this the correct way to determine the maximum value for Vsupply?
Since i don't know R2 i can't determine this
c)When Vsupply=5 V
The zener Z2 will be inversely polarized and so V 500 Ohm=5 V
Is this correct?
Thanks
Last edited: