Re: T8s, instant start, and e-ballasts

>>3) And finally I heard someone mention that e-ballasts designed for a
>>4' tube shouldn't be used to drive 2' tubes even thought they might work.
>>Is this so, and why?
>For the same reason you wouldn't use a household extension cord to run
>heavy farm equipment. Current and voltage capacity are important.

Actually, it's OK to use a current regulated 4 foot electronic ballast to
drive 2 foot tubes. The ballast will output the same current, just at half
the voltage. The Magnetek I am using drives 2 foot or 4 foot tubes just
fine. However, rather than use that four foot ballast to drive a single two
foot bulb per output, you can drive two two-foot bulbs in series per
output. Electrically it will be the same load as a four foot bulb. These
ballasts don't use the starter filaments, rather they deliver very high
voltage on startup to get the bulbs going. Hence, there's no need to be
concerned with wiring for the preheating filaments.


Paul Nicholson               Electronic Imaging Systems, Inc.
TEL 805 532 1068             5148 Commerce Avenue, Unit F
FAX 805 532 1065             Moorpark, CA 93021 U.S.A.
paul at eisusa_com		     http://www.eisusa.com