2 Zeners versus 1 zener- inconsistent with actual theory?

  • #1

Main Question or Discussion Point

So when I have two zeners connected, I should get less voltage than if I had one, but this is NOT the case!!! Why?
I don't understand- two zeners of say 1000 V each- say we have a power source than provides 2500 volts- then we should get only 500 V. With one of these zeners, we should get 1500 V. But it's almost reversed, and I don't get why..
Thanks!!!
 

Answers and Replies

  • #2
247
1
wushumaster,

You should probably include some details like how the zeners are connected. Next you should explain why on earth you are attempting to use zeners with a 2500V supply. You should probably include some details about your supply voltage, at the very least confirm that it is a DC supply.

Fish
 
  • #3
berkeman
Mentor
57,263
7,247
So when I have two zeners connected, I should get less voltage than if I had one, but this is NOT the case!!! Why?
I don't understand- two zeners of say 1000 V each- say we have a power source than provides 2500 volts- then we should get only 500 V. With one of these zeners, we should get 1500 V. But it's almost reversed, and I don't get why..
Thanks!!!
When you connect two zeners in series, the overall voltage drop is the sum of the two zener voltages.

When you connect two equal-value zener diodes in parallel and drive them with a current source, the voltage drop is slightly less than when you have just the one zener diode. That is because the two parallel zener diodes are splitting the available current, so each diode voltage is a little less since it's running at a lower current.

http://en.wikipedia.org/wiki/Zener_diode

.
 
Last edited:

Related Threads on 2 Zeners versus 1 zener- inconsistent with actual theory?

  • Last Post
Replies
4
Views
3K
  • Last Post
Replies
3
Views
711
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
13
Views
2K
  • Last Post
Replies
8
Views
11K
  • Last Post
Replies
2
Views
8K
  • Last Post
Replies
2
Views
5K
  • Last Post
Replies
1
Views
13K
  • Last Post
Replies
1
Views
6K
Top