Re: Electronic Ballast for Fluorescent Light [Hack] ?

In <14555-484A03EA-1129@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, C. Nick Kruzer wrote
in part:

TWO 20W ballasts in parallel WILL shorten the
life of the tube electrodes by applying too much
heating current, hence releasing mercury inside
the tube from the electrodes.

Mercury!!...I don't want to become the "Mad Hatter"! :-)

That was talking about evaporating mercury from the electrodes to the
inside of the tubing.

This is somewhat incorrect - in normal operation, the electrodes
are too hot to have any mercury at all on them.

Overheating the electrodes will merely shorten their life by
accelerating evaporation of the thermionically emissive material that
the electrodes are coated with.

In any case, the mercury stays inside the tube.

Combining ballasts is merely a *Big Bad Idea* for the other reasons
(edited out for space). You are unlikely to match the proper wattage and,
voltage, the electrodes have a fair chance of shortened life, and the
ballasts are independent high frequency AC generators that are unlikely to
synchronize with each other.

One more good reason - UL listing of electrical equipment (including
fluorescent lamp ballasts) is invalid when they are used other than as
directed. Your fire insurance company and your landlord may cause you
major grief if you burn up your apartment (and any other apartments) from
abused ballasts going KABLOOEY, as opposed to having a fire starting from
them despite using them as directed (which is presumably much more
unlikely).

- Don Klipstein (don@xxxxxxxxx)
.

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