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How can I tell whether I have a magnetic ballast or an electronic ballast?

While commercial test equipment is available for determining whether a magnetic ballast is in place, there is an inexpensive do-it-yourself test that can be done with your cell phone!

Just point your cell phone camera at the lamp, and take a picture.  If the image displays dark bands or stripes, your fluorescent lamp is driven by a magnetic ballast.  A modern, electronic ballast drives the lamp at a much higher frequency, and a picture of these lamps will be clearly different, without such bands.

The image below shows a T12 fluorescent lamp with the tell-tale bands generated by a magnetic ballast:

The image below shows a T8 fluorescent lamp with a steady glow indicating that it’s driven by a modern electronic ballast.

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