Hey !




i didn't solve problem with filer and regulator in conducted to each other before.
so i got a problem in solving this question
http://www.mypicx.com/uploadimg/1353517504_03202011_1.png
http://www.mypicx.com/uploadimg/1190819516_03202011_1.png


I tried to solve it and this is my attempt:

for the filter:

vp = vs - Vd = 14.3 v
Vo = vp - 0.5 vr = 13.8v

for the regulator:
vz = Vzo _ rz*iz => Vzo = 9.8 v

and here i don't know how to get R ! and the question is not clear to me

 

Your links don't work or are too far away to work or the server for them is asleep. So please post your schematics here instead of way over there.

 

i don't know what the problem is , but i uploaded them in the attachment now

 

If one assumes the 1V ripple is the filter capacitor voltage ripple then .........

The capacitor voltage would have a peak of 15-0.7=14.3V and a minimum of 13.3V [since ΔVcap=1]

The mean capacitor voltage would be ~(14.3+13.3)/2=13.8V

A mean zener current of 20mA [for nominal 10V zener voltage] would require a total series resistance

R+rz=(13.8-9.8)/20mA=200Ω

Hence R=190Ω [since rz=10]

Required capacitance....

The discharge time=asin(13.3/14.3)/ω+T/4=3.17ms+4.17ms=7.34ms

Hence C=I*Δt/ΔVcap=20e-3*7.34e-3/1=146.8uF

I have the unloaded zener ripple voltage as 50mV.

 

With the 22uF instead of 146.8uF the load ripple is obviously going to be larger. The problem in this case is that the linear capacitor discharge assumption breaks down and one must solve for the ripple in an iterative manner or by direct simulation.