Four foot fluorescent fixtures were all preheat (blinky blink) until the late 50's, when RAPID start was introduced. Preheat 40 watt fixtures are pretty scarce these days, as most of them got junked, or converted to rapid start. Preheat 20 watt fixtures are still fairly commonplace, as TRIGGER start (two foot version of RAPID start) did not get here until a little later. Nowadays, rapid start 40 watt fixtures are being junked in favor of newer 32 watt INSTANT start fixtures with electronic ballasts, whereas the older equipment had magnetic iron core ballasts.
I'm an expert on industrial lighting. Before TVs, I was a hard-core collector of vintage fluorescent and HID lighting.
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"If you wish to make an apple pie from scratch, you must first invent the universe." -Carl Sagan
Last edited by TUD1; 10-11-2017 at 12:13 AM.
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