Diode strings - equalizing resistors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Richard W." <potluckutk-at-comcast-dot-net> 

Hi List,

I have a question concerning the use of equalizing resistors on diode strings.
I've heard it said the reason for the resistors is that if one diode turns 
off before the others then all voltage may be seen across that one diode. 
That makes sense if the diode turns off anywhere else but close to zero 
crossing. But the diode/s won't trun off until the voltage is near or at 
zero crossing. At that point there really shouldn't be enough voltage 
anywhere in the string to overwhelm the PIV spec of any one diode if the 
diodes are rated at 700 vrms or 1000PIV.

Is my thinking amiss?

Rick W.
Salt Lalke