amdx fired this volley in news:lrofd8$fme$1@dont-
email.me:

Here's a page that said they were made with a thermistor.
http://www.understandwebsites.com/bu...ernatives.html
Mikek

There may have been "soft-start" versions of them that were NTC
thermistors; that, alone would have lengthened the life of the bulb,
without dimming it much.

It's been a long time since I saw those, but the ones I remember dimmed
the light a LOT, which makes me think that some of them were diode-based.

The NTC thermistor makes more sense, though. It would have only
dissipated enough energy to keep itself hot.

Lloyd