What is the advantages of voltage regulator over the Zener Diode ?

[nguitar12]

I saw many circuit are use voltage regulator 78lxx over the Zener Diode.
What is the advantages or disadvantages of both?

[Digital Larry]

Voltage regulator will usually give you:
Better regulation over a wider range of load currents and input voltages
Higher current capability

Zener will give you:
Less expensive implementation
Adequate regulation for some applications

[nguitar12]

Voltage regulator will usually give you:
Better regulation over a wider range of load currents and input voltages
Higher current capability

Zener will give you:
Less expensive implementation
Adequate regulation for some applications

Thanks. I will stick to the Voltage regulator then 

[antonis]

I will stick to the Voltage regulator then 

Excellent choice..

(but you can also try to bias a npn BJT's base with a Zener of 700mV higher than your desirable voltage - which also involves some degree of fun... )

[R.G.]

There's a fundamental point to be appreciated here.

Three-terminal regulators, including the 7800, 7900, and LM317 series, are series regulators. That is, they have some variable element in series with the incoming voltage/current, and only let through enough current to get the voltage to be correct.

Zeners and some reference ICs are shunt regulators. They critically must have some series current limiter between the active element and the incoming voltage/current. The series current limiter is nearly always a resistor, and the resistor is sized so that at the maximum possible current for the regulator's output, the resistor drops the difference between the incoming voltage and the outgoing voltage. The shunt regulator circuit is designed to shunt current to ground in an amount that always keeps the output voltage constant. With zero output load a shunt regulator has to "eat" all the current.

Series regulators generate the least heat when their loads have the least current; zero load is usually fine.  Shunt regulators get hottest when there is the least load on their output, as the regulator has to eat all of the maximum power that would otherwise go to a load.

Shunt regulators have special design problems in that you must anticipate all the possible variations in the incoming voltage and allow a low enough series resistance to let enough current through at maximum load but minimum input voltage, and at the same time design the shunt regulator itself to dissipate the maximum possible load current times the desired output voltage, while making the series resistor able to dissipate the maximum load current times the difference between the maximum input voltage and the output voltage.

Series regulators are easier to design with because you only have to design the regulator to dissipate the power at maximum load current and maximum input voltage.

Zeners are shunt regulators.

[amptramp]

What should be noted from R.G.'s description is that if efficiency is your primary concern, then series regulation is preferred.  If your primary concern is to minimize the noise current and current variation reflected back into the source then shunt regulation is preferred.  Take your choice.

[MrStab]

When i was trying to limit the input voltage of a charge-pumped boost a while back, i settled on a zener because my goal was more to limit the maximum voltage, and less to ensure a constant voltage (that sounds kinda stupid reading it back, but hopefully you know what i mean lol). That doesn't mean the same considerations and caveats don't apply (check your power ratings!), but i thought i'd just share what went through my mind. I weighed up my needs against board space and complexity. If I expected the input voltage to constantly exceed the desired amount, then i probably would've went with a regulator for peace of mind, but i just wanted any occasional overvoltage to be shunted.

...y'know, in case one of those people with that eye problem where the number 9 looks like the number 18 happens to use the pedal