Originally posted by: funboy42
Bad wiring I wouldnt say because it will either work or not and if it didnt work he'd be poping circuit breakers then the bulbs. You only have 2 wires going to the bulb. Now the other two I can see and the vibration maybe but thaat thing it gonna have to be vibrating like mad.
Filaments are made chiefly from tungsten, an extremely hard and brittle metal with high melting point. Lots of vibration will weaken the filament especially in conventional bulbs not designated for "rough service".
Turning a tungsten lamp on is a terrible thing to do! Cold wolframite (filament) has an extremely low resistance - practically a short. This quick inrush current causes stress on the already weakened filament. This is why most tungsten lamps blow when energized. So called bulb savers - those little buttons that are placed beneath the socket on the lamp - use a thermistor and diode. This allows the bulb to run on half wave rectified DC and start slowly reducing the stress of a cold start.
Originally posted by: Shawn
The fan doesn't really vibrate at all, even at highest speed. Also I'm only using 60w bulbs.
Are you sure? Wobble that's readily apparent doesn't constitute vibration.