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Posted to alt.engineering.electrical,sci.electronics.repair,alt.sports.baseball.sd-padres
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Another fluorescent nightlight dissected
"Lynn" wrote in message
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"James Sweet" wrote in message
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http://picasaweb.google.com/lh/photo...eat=directlink
This cute little First Alert nightlight someone gave me a while back
lasted all of 6 hours before it failed. The lamp is a small U-shaped hot
cathode fluorescent made of tubing roughly 11mm diameter. R3 was burned
beyond recognition but measured around 32K which may or may not be close
to its original value and both cathodes in the lamp are open. All
resistors are 1/4W except for R2 which appears to be a 1/2W fusible type.
D1, D2, C1, and C2 form a half wave bridge voltage doubler. R1 and R5
discharge the capacitors when the unit is unplugged. R2 serves as the
ballast, limiting current in the tube, while R3 and R4 provide current to
heat the cathodes. Running the tube from DC can't be good for it under
the best of circumstances but I would hope these typically last longer
than this one did.
now you know why someone gave it to you
why don't you shut your ass up you ****ing ****?
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