A Cure for Hot Snubbers (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 15 Oct 2004 07:23:58 +0930
From: Matthew Smith <matt@xxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: A Cure for Hot Snubbers

Hi All

I'm working on some very low powered (NiMH battery supply) high voltage circuits.

One thing that concerns me is snubbers getting hot.  I'm using an integrated 
switcher which current limits itself, so at least I've got rid of the heat 
(wasted energy) there.

Now, am I getting this right?
* The snubber exists to prevent the switching device from getting cooked.
* All energy that isn't transferred to the secondary goes through the snubber.
* All I really want to cut is voltages greater than the switch can handle.

So...

If I use a fast diode in opposition to another (Zener?) diode as I have seen in 
some circuits that will only pass voltages over a little below the switch's 
maximum voltage, there will be considerably less energy wasted.

Is this correct or am I barking up the wrong tree?

Cheers

M

-- 
Matthew Smith
Kadina Business Consultancy
South Australia

Outside temperature:  18.2 degrees Celcius.
Wind due WNW,  6.1km/hr gusting to  8.0km/hr
Temperatures today (avg/max/min):   7.8/ 20.5/  5.2 degrees Celcius.
Max wind speed today  8.0km/hr at 07:05
Precipitation today: 0.000mm