On Wed, 3 Sep 2003 03:31:59 -0700, Watson A.Name - "Watt Sun"
wrote:

The bulb savers that I used back in the '70s were varistors. They
slowed down the turn-on of the light. They were low resistance when
warm, and high when cold. There was no diode.

These were actually Metal Oxide NTC thermistors back then (not Metal
Oxide Varistors), since silicon diodes were at that time just a
curiosity in the "ELECTRICAL" world as opposed to the "ELECTROMICS"
world. The problem with the Diode or the NTC solution, is that it does
nothing to save the bulb from line transients.

I have seen actual VARISTORS being used for current regulation as
opposed to surge suppression (clipping), but only in old telephone
sets. I'm not shure of the principle behind this since a MOV is not a
temperature sensitive device, and am curious if anyone can explain.

A ballast based voltage drop, has better potential in that regard when
combined with a VARISTOR and fuse for surge suppression. So for an
extra $50.00 you get to keep your bulb longer. Hmm.

Stepan