# Zener Diode with LC circuit

1. ## Zener Diode with LC circuit

Hi guys,

I've been wanting to ask if there's any way to place an LC circuit with the reverse-biased operation of a Zener diode. Would it be possible to have that in a reverse-biased condition? Everything I've searched on was in forward-biased operation.

Also, can you give me tips on how to design an L and C values? Thank you!

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2. ## Re: Zener Diode with LC circuit

It’s not clear what you’re asking for. I have no idea what you mean by “an LC circuit with the reverse-biased...” could you maybe draw a schematic or describe what you are trying to do? How do you expect anyone to give you “tips” on L and C values when we don’t know what you’re doing?

3. ## Re: Zener Diode with LC circuit

Hi,

I agree.

L and C have frequency dependent impedance. So how can you expect that anyone can give values, while you don't give any input like, frequency, voltage, current?
And you are posting in the "Power Electronics" section, thus I assume this is neither "logic level voltage" nir current in the microamperes.

Without additional information the whole thread is considered useless and may be deleted.

Klaus

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4. ## Re: Zener Diode with LC circuit

Originally Posted by barry
ItÂ’s not clear what youÂ’re asking for. I have no idea what you mean by Â“an LC circuit with the reverse-biased...Â” could you maybe draw a schematic or describe what you are trying to do? How do you expect anyone to give you Â“tipsÂ” on L and C values when we donÂ’t know what youÂ’re doing?
Sorry, I wasn't clear. I am actually doing overvoltage protection circuit using the commonly used Zener diode (going to use it in Reverse-Bias Operation). During reverse-bias configuration below breakdown voltage, there's ideally no current passing in the diode. But when it reaches the voltage breakdown, the current would start to flow.

I am trying to find a way to kind of harvest that excess current to the inductor for a little time and store it to a capacitor. Something like this picture but add a reverse biased diode after the supply and in parallel with LC.

I have actually tried to simulate it and at first, it's okay. But after the capacitor's reached its stable voltage, the vout started to be similar with the input's value (it isn't protecting anymore).

Please let me know what you think. Thank you.

5. ## Re: Zener Diode with LC circuit

Sounds like you are inventing the SMPS concept again!
A Zener only works as a clamp in reverse biased direction, in forward mode it works like a normal diode.

Brian.

6. ## Re: Zener Diode with LC circuit

Originally Posted by sylviii
Sorry, I wasn't clear. I am actually doing overvoltage protection circuit using the commonly used Zener diode (going to use it in Reverse-Bias Operation). During reverse-bias configuration below breakdown voltage, there's ideally no current passing in the diode. But when it reaches the voltage breakdown, the current would start to flow.

I am trying to find a way to kind of harvest that excess current to the inductor for a little time and store it to a capacitor. Something like this picture but add a reverse biased diode after the supply and in parallel with LC.

I have actually tried to simulate it and at first, it's okay. But after the capacitor's reached its stable voltage, the vout started to be similar with the input's value (it isn't protecting anymore).

Please let me know what you think. Thank you.
Um, where’s the zener? This is making less and less sense. If you actually did have a zener in parallel with the LC, it would just conduct unlimited current when the input voltage exceeds the zener voltage.

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7. ## Re: Zener Diode with LC circuit

Um, where’s the zener? This is making less and less sense.
Also, to test an overvoltage protection circuit, we would expect a pulse voltage source, a switched voltage or something similar. Not a battery.

I'd appreciate an elaborated problem specification.

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