Author Topic: Zener in rectifier  (Read 1245 times)

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Offline KaratzinisTopic starter

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Zener in rectifier
« on: April 11, 2019, 10:55:54 pm »
Hi
Can I use a zener diode, e.g. Vz=43V, in a rectifier to suppress overvoltages while it is in blocking state (nominal blocking voltage is 30V). A diode of 40V sometimes is damaged from voltage spikes. Could a zener be a solution ? When using a zener it seems to supress the peak voltages but is there any danger for short circuit the output or break down ?

Thanks in advance.
 

Offline Hiemal

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Re: Zener in rectifier
« Reply #1 on: April 12, 2019, 12:43:49 am »
I don't think you're using the zener correctly here.



Is something more appropriate I think.
 

Offline ArthurDent

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Re: Zener in rectifier
« Reply #2 on: April 12, 2019, 12:44:37 am »
Just use a higher rated rectifier diode in the 100 to 600 volt range. If the ringing you show in your drawing is from a switching mode power supply, make sure you use a fast diode.
 

Offline David Hess

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Re: Zener in rectifier
« Reply #3 on: April 12, 2019, 04:58:50 pm »
If breakdown across the normal rectifier is damaging it, then using a zener may not help.  Also, zener diodes are slow and not suited for switching power applications.

An avalanche rated rectifier may be exactly what you need.  Like TVSes but not zeners, they use special processing so that reverse breakdown takes place uniformly across the junction instead of allowing hot spots to form.
 

Offline KaratzinisTopic starter

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Re: Zener in rectifier
« Reply #4 on: April 15, 2019, 05:52:57 pm »
Thank for the responses, I think I will just go for a higher rated typical diode. More general, even using TVSs I wonder if it's good practice to have a component in a rectifier that can partly "open" to suppress any voltage spikes that could appear.
 


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