# How to calculate Load Regulation

Discussion in 'Homework Help' started by jegues, Mar 17, 2011.

1. ### jegues Thread Starter Well-Known Member

Sep 13, 2010
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45
How would I go about calculating the Load Regulation in this circuit? Note that we don't know the value of RL.

After doing some wiki'ing, I have to find the Voltage(Full Load), where IL = 20mA, and Voltage(Min. Load), where IL = 0mA.

I have done this correctly?

Also if I calculate a load regulation of 84% does that mean that the output changes by 84% or that it regulates 84% of the output?

See figure attached for my attempt and question statement.

EDIT: Also, for part e), how do I calculate the maxmimum power dissipation if I've solved for the maximum current?

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Last edited: Mar 17, 2011
2. ### jegues Thread Starter Well-Known Member

Sep 13, 2010
735
45
I'm pretty what I've got in my OP is incorrect.

Here's my 2nd shot at it. Am I on the right track?

What would IL be for no load? Is it modeled as a short circuit or an open circuit? If I know this I can find IL.

Also, what do they mean by full load condition?

Thanks again!

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3. ### Jony130 AAC Fanatic!

Feb 17, 2009
4,203
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All current provides provided by R flow through Zener diode

R = (15V - 9.825V)/ ( 25mA ) - 7Ω = 200Ω

ΔVo = rz/(rz+R) * ΔVs = ± 169mV

Output impedance is equal

Rout = R||rz = 6.7632Ω ≈ 7Ω