Joule Thief

[TheNOP]

If I go to the shop and buy a light fitting, say for example a 100Watt light bulb, it will consume "more" wattage/current to produce the 100 watts of light, so it can give the stated output?

BUT,,,,will the same   100 watt light bulb take more current to run, 
if it is a bulb rated at 240v at 50Hz or
                             120v at 60Hz?

Remember, as the voltage is lowered, the current go's up to compensate for the lower voltage.

jim

i just had a flash and think i understand what you really meant.

to understand what is happening, you need to know how those bulbs are working.
basicly: An electric current passes through a filament, heating it to a point is produce light.

the key factors of the quantity of light are :
- the filament's total surface area.
- how bright it glow(the resistance control the watts that make it glow).

assuming a 240volts bulb is made from the same materials as a 120volts bulb.
the only thing that can make a difference are the 2 things above.
in order to allow the same wattage at 240 and 120 volts, you need a filament of different resistance for each one.
the 240volts filament will be thinner and longer.
the 120volts that will be thicker and shorter.
you should end up with about the same surface area for both,
and with same wattage, you will get the same amount of light.
one is using more current, yes.
but, with the same materials and different resistance, they use the same quantity of energy to make the same quantity of light.

you can try to connect a 120volts bulb to a 12volts 600 amps car battery, you won't be able to make the required amps to flow through the filament to reach 100 watts because of its resistance.

[stprue]

Neve mind the order of the pic's is correct

I forgot to mention for those of you that don't know my power supply is set to 1.5vdc@.5amps  The set up above uses about .43 I think

[stprue]

i just had a flash and think i understand what you really meant.

to understand what is happening, you need to know how those bulbs are working.
basicly: An electric current passes through a filament, heating it to a point is produce light.

the key factors of the quantity of light are :
- the filament's total surface area.
- how bright it glow(the resistance control the watts that make it glow).

assuming a 240volts bulb is made from the same materials as a 120volts bulb.
the only thing that can make a difference are the 2 things above.
in order to allow the same wattage at 240 and 120 volts, you need a filament of different resistance for each one.
the 240volts filament will be thinner and longer.
the 120volts that will be thicker and shorter.
you should end up with about the same surface area for both,
and with same wattage, you will get the same amount of light.
one is using more current, yes.
but, with the same materials and different resistance, they use the same quantity of energy to make the same quantity of light.

you can try to connect a 120volts bulb to a 12volts 600 amps car battery, you won't be able to make the required amps to flow through the filament to reach 100 watts because of its resistance.

That's right and the 240 stuff will also last longer!  Well not sure if the last sentence is correct!

[TheNOP]

thaelin i believe its the amps thats the killer, more specifically down to 0.01 amps can stop a heart. anything lower than that and you will live. it will hurt, possibly burn, but you will live.

it depend on a lots of factors.
mainly, your body resistance and the travelling path of the current through the body.

taser are said to output less amps then what is said can kill.
still, peoples have died because a taser was use on them...

don't fool with high voltage, it won't be forgiving.

[gadgetmall]

Artic_Knight

I agree   that  RF interference  could be a problem

If I was trying to  covertly  stop  JTs from  being used I would probably  talk  with the FCC .
I think we  should be careful .......especially  when  we start   using higher power .

JTs might  be transmitting more power than expected .

I was reading a magazine ( Popular  Mechanics I think )
I  read about  a new idea for  a radar antenna  for  stealth  fighters .
I guess  a problem with  stealth  fighters is  their  antennas  are visable  to  radar . 
This antenna was different . ......it was a glass tube filled with a gas .....argon if I remember right .
The  antenna is  invisable  to radar because  it  is  non conductive .   
When they want to use the radar  they  apply enough  voltage  to  ionize the
the  gas ,creating a good  conductor   .

Now .......if  an argon  filled tube can be used as an antenna .....  wouldn't it make sense that  a floro tube  would also tend to act as an antenna if the  frequency   was high enough ?

gary

I'm A licensed Amateur radio operator and can transmit all frequency's in the ham band including hf vhf uhf microwave , radar etc.. so let em try and stop me !! Yes they are all transmitters but i doubt they go out the confinements of our houses ,yards ecs .. Now the SEC that's a different story on the distance . can't wait for My Sec parts !! The Argon tube radar reminds me of the gigaplexer i played with 15 years ago . you can also pick up those signals on an old radar detector . I have had Jet fly over and My detector go full strength and then diminish after the jet went by ..Cool .  if wort come to worst a jt can be caged and shielded and stray rf probably can be minimized with ferrite beads on the leads of the parts ETC and tuning to rid the offending harmonic .. I might try this on My Tv disruptor  or i might just sell it as a Tv disruptor

Al