Transient Suppressor ratings

Mosaic

Well-Known Member

• Apr 13, 2015

• #1

Hi all:
I have an app that is popping paralleled TV 1.5KE33CA units.
I guess they are clamping at slightly different voltages and popping in sequence, one at a time.

As opposed to placing some .01 ohm current shunts to equalize loading, how about using some lower voltage units in series to share the load?

 

Cicero

Active Member

• Apr 14, 2015

• #2

What about putting a polyfuse in series beforehand? It'll kick in and shut it all down until the problem goes away.

EDIT: Do you have an idea of what kind of overload conditions are happening? Duration? Levels?

 

Last edited: Apr 14, 2015

Mosaic

Well-Known Member

• Apr 14, 2015

• #3

Looks like about 70A of kickback current over 5uSec

 

Cicero

Active Member

• Apr 14, 2015

• #4

Ah ok, polyfuse wont kick in quick enough then.

Sounds to me like you need a suitable snubber? Is there no kickback diode either?

 

Mosaic

Well-Known Member

• Apr 15, 2015

• #5

Got it working with a pair of 1.5KE36CA limited by 1 Ω resistors.
They run hot (92°C) without forced air cooling, but I'll add that.
They're each handling about 25A for 0.25%DC.
The kickback voltage has dropped to around 40V (from 55V) with less ringing, so the FET switch shouldn't avalanche.