View Full Version : Zener Diod 1N4733A

Jorge P
08-20-2011, 05:39 PM
I bought a few of these zener diodes (1N4733A) and have never used them. Can I use them to replace a few shottkey diodes as in this circuit?


The solar panels I am using are two 6V cells in series, the battery pack is 8 NiMh AA's. I don't have any Schotkey diodes on hand.

I will place a regular diode between the cells to prevent reverse voltage? the voltage to the board has an input voltage rating greater than what the cells can put out which is ~18V no load.

I've never used schottkey diodes either so sorry if this sounds like a dumb question.

The data sheet for this Zener Diode is http://www.alldatasheet.com/view.jsp?Searchword=1N4733A

Thanks for your help with this.

08-20-2011, 05:50 PM
No. They are quite different from Schottky diodes.

PJ Allen
08-20-2011, 05:53 PM
A schottky is like any rectifier diode, basically, it just has a lower forward voltage drop.

A zener has a forward voltage drop like any rectifier diode. It is different in that it will hold off current when reverse biased until the zener breakdown voltage is met where it will begin to conduct. And, they're leakier, too.

So, Schottky diodes aren't zener diodes only with different funny names.

I wouldn't do what you suggest. Someone may come along and tell you, "It's OK."

Jorge P
08-20-2011, 06:32 PM
Thanks for the quick replies, I'll just wait till I get some shottkys, and I knew they were not the same, just thought I'd ask to see if I could use what I had on hand. That's what I get for not writing down my parts list when I went to the store last time, picked up the wrong diodes.

08-20-2011, 10:50 PM
Zeners can be tricky. I use 3.6v zeners to build
USB circuitry for Tiny85 uc's. I discovered that
for some reason the 1amp versions were cranky
and the 500ma lower rated parts worked much better.

PJ Allen
08-20-2011, 11:15 PM
You can always count on low-voltage zeners to be "cranky".
Never bet the farm on them, get a TL431 or similar.