[SOLVED] zener diode as a voltage regulator

[jeffrey samuel]

hi all
when zener diode is used as a voltage regulator how does the output voltage retained as constant across the diode

do explain it to me

 

[tpetar]

Zener Diodes can be used to produce a stabilised voltage output with low ripple under varying load current conditions. By passing a small current through the diode from a voltage source, via a suitable current limiting resistor (RS), the zener diode will conduct sufficient current to maintain a voltage drop of Vout. DC output voltage from the half or full-wave rectifiers contains ripple superimposed onto the DC voltage and that as the load value changes so to does the average output voltage.

All you need :

https://www.electronics-tutorials.ws/diode/diode_7.html

**broken link removed**

 

[sky_123]

At a semiconductor level? You'd need to check some physics or electronics textbook (not really possible to describe in a few sentences). But the I-V characteristic (e.g. see Wikipedia page on Zener diodes) should show you why at an electronic level; it is because the I-V curve is rather flat at a certain voltage in the reverse direction, regardless of current drawn. The page also tells you that a zener effect and an avalanche effect cause the I-V curve characteristic; probably a textbook or at a pinch Wikipedia will have more info on these.

 

[jeffrey samuel]

thank u but does the regulated voltage from the zener diode has a time delay or is it instantaneous that is what is the time difference between the point of change in voltage across the load to the reaction to the change by the zener diode

 

[sky_123]

Good question! I'm not sure, maybe others know. The avalanche effect is pretty fast!

 

[tpetar]

I think that this data we should check in manufacturer datasheet of particular zener. There is ultra fast zeners and general purpose zeners. Maybe you should read some material about ESD protection, that is linked with this.

You can see some material about ESD protection :

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[jeffrey samuel]

thanks all
for all your help

 

[tpetar]

No problems we help each others.

;-)