Schottky diodes as voltage clamp

[mrmaxy]

I am looking to clamp the speaker return voltage on an amplifier by putting Schottky diodes across the main psu smoothing capacitors. The only ones I have available have on the data sheet 60-100v. I wasn't aware but this looks like minimum voltage of 60v.

Does this mean the diodes won't work with just a few volts across them ?

http://www.farnell.com/datasheets/468446.pdf

Thanks

 

[Mooly]

That voltage rating is the PIV or peak inverse voltage... the maximum it can stand reverse biased.

Two things 🙂
If you do fit diodes then they need to be rated to at least the voltage rating of the reservoir caps plus 50% or so for a good safety margin.

I'm dubious on the benefits tbh. Does anything in music (as opposed to custom designed test signals that exploit a particular speaker to get the "worst from it") ever generate any measurable transients at all ?

 

[WSJ]

That means the data sheet includes 4 diodes with different maximum voltages.
This type of diode does not have a minimum voltage.

 

[Mooly]

And some more info here,

http://www.diyaudio.com/forums/solid-state/95780-output-clamping-diodes-when-do-we-need-them.html

 

[Mooly]

That means the data sheet includes 4 diodes with different maximum voltages.
This type of diode does not have a minimum voltage.

The data sheet covers four devices of the same series. Forward biased and the device conducts, dropping whatever the forward voltage is for a power shottky (around 1 volt at its max current). Reverse biased and its non conducting all the way up to the voltage at which it fails. That's where the PIV rating comes in.

 

[mrmaxy]

Thanks Mooly, Wsj. Appreciated