Electronic Devices - Diode Applications - Discussion

Since R and RL are fixed resistors the maximum value for source voltage would be dependent on the Izmax.

Vsmax = (IRmax)(R) + Vz.

IRmax = IZM + IL; and since VZ, RL, IL, R is constant IRmax depends on the value of IZM and in turn the Vsmax would depend on the value of IZM.

Vs = Is * R + Vz.
Or.
Vs = Is * R + Izmax * Rz.

Zenar diode is used to maintain the constant output voltage. So to maintain the output voltage constant we should maitain Iz should be maximum.

Is = Iz + IL.

Here Iz should be maximum, when zenar diode operates in the Reverse break down region the current throgh the zenar diode will increases. (see zenar diode charecterstics).

So that the manimum IL can pass through the load then IL*RL will maintain canstant.

For this purpose Vs >= Is * R + Izmax * Rz.

So that, the source voltage mainly dependent on Iz (zenar diode curent) which sholud be maximum.

I'm not agree so that explain me.

I can't understand please explain in detail.

Izm dictates because Izm carries maximum current through zener diode very and small current passes through load.

Yes maximum amount of source always passes through the active elements.

The V across RL cannot exceed 20 v so the max current IL is 20/1.2K = 16.67 mA so max Is is 16.67+60 mA.

Vs max = 76.67 mA * 220ohm + 20V = 36.87V.

The max amount of source always should passes through the active elements.

Current across that potential voltage (vz) is low so that it is iz is to be max.

Can you tell in detail.