Fluorescent Lights

[denderah]

I have some questions which may seem strange, but this is for part of a project I am working on.

 

1) How necessary is low pressure argon gas in the operation of a fluorescent light? Would a normal pressure argon work with less efficiency, or would it not work at all?

 

2) Can I power a fluorescent light from a Magnetron? Do you have any thoughts on what the best way would be to do this?

 

Thanks for your input

[Pleiades]

I’m no expert, but I’m pretty sure it has to be at fairly low pressures. As Mr. Wizard taught us, a fluorescent tube will light up if you put it in the microwave. So yes, a magnetron should do it.

[Apeofman]

I’m no expert, but I’m pretty sure it has to be at fairly low pressures. As Mr. Wizard taught us, a fluorescent tube will light up if you put it in the microwave. So yes, a magnetron should do it.

 

In a dark room, rub the tube with a woolen cloth. See what happens when you remove it.

 

Albert Einstein also said

[ed84c]

Walk under a high voltage power line with one, on a dark night (take a torch so you can see what you walking into ).

 

Which reminds me, if we are getting light energy from the tube when walking into a magnetic field (ocelating- (i cant spell)) where does the energy come from to power this flourecent light? Are you some how sapping the wires of voltage, and if (say) the wires had 0 resistance, some energy must be lost somewhere to allow for people wandering under power lines with light bulbs.

[flyboy]

its the magnetic field generated by the high voltage wires

[ed84c]

yeh but my point was if this magnetic field is producing light energy in my experiment, the conservation of energy means this light energy must come from somwhere, does this mean that there is a voltage drop relating to the production of magnetic fields?

[jdurg]

Yes, low pressures are required for the operation of a fluorescent light bulb as at normal pressures gases are simply too good of an insulator. You would need to apply a MASSIVELY high voltage in order to complete the circuit and that would be a huge waste of power and a VERY inefficient method. By using a reduced pressure gas, the electrons are able to move from one electrode to the other. In other words, at low pressures gases can conduct electricity at much lower voltages than are required at higher pressures.

 

In fluorescent bulbs they also have a miniscule amount of mercury metal in there. The low pressure causes the mercury to vaporize which allows it to pass a current much better and also creates ultraviolet light when a voltage is applied across the electrodes. This UV light strikes the phosphors on the inside of the bulb causing them to fluoresce, hence the name "fluorescent light".

[denderah]

Thanks for all the replies.

 

Also - I read on wikipedia that fluorescent lights flicker at a rate that depends on the driving voltage.

 

Is anyone able to describe what it would do to the flicker rate it the fluorescent light was being powered by a magnetron?