zener diode voltage regulation

[devil6600]

i have 5v 3amp supply and i want it to be regulate at 4.3v 3amp, how much watt zener diode do i require?
i tried with 4.3v zener diode but it got damaged.
i do not want to use adjustable voltage regulator

 

[AMSA84]

Have you thought put a "normal" diode, within the specifications of you power supply, in series with the output?

Regards.

 

[jeffrey samuel]

check the power rating of the diode which got destroyed and replace it with one of little higher wattage

and zener diode damaged for 5 V supply is really a strange issue never heard or seen check the supply also for some leakage that may have damaged the zener also try limiting the current through the circuit

 

[alexan_e]

If you are just using a resistor and a zener to get 4.3v/3A from 5v input then you need a 12.9W zener :!:

Alex

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and zener diode damaged for 5 V supply is really a strange issue never heard or seen

Why do you find it strange?

 

[devil6600]

Have you thought put a "normal" diode, within the specifications of you power supply, in series with the output?

Regards.

thanks for pointing, i already tried that but results were not constant. sometimes i got 4.4v or 4.5v
i would be using the same supply to power gsm module, it requires sudden current of 2amps, if i put diode in series will it be ok for gsm module?

 

[goldsmith]

Hi devil !
One of the best ways that you can use is an op amp + a potentiometer + a series pass element such as a darlington pair !. and some simple resistors ! or if you don't want this way , you can use a simple TL431 and then a darlington pair !
Best Wishes
Goldsmith