Re: VU1 ESL bulbs with HA dimmers?

[nobody@xxxxxxxxxxxx (Dave Houston)]

Like I said, it's been nearly 50 years since I learned about CRTs. In those
days electrostatic deflection was prevalent.

This page gives an explanation of the x-rays and of the high voltage. I
still am pretty sure that these new bulbs will not have such high voltages
nor emit x-rays.

     http://en.wikipedia.org/wiki/Cathode_ray_tube

Charles Sullivan <cwsulliv@xxxxxxxxxxxx> wrote:

>
>Hold on there...  The horizontal and vertical deflection of the electron
>beam in a TV CRT is normally accomplished magnetically with steering
>coils.
>  http://electronics.howstuffworks.com/tv5.htm
>
>On Thu, 24 Sep 2009 14:36:27 +0000, Dave Houston wrote:
>
>> Where did you get "voltage of the electron emitter beam"? Heating the
>> cathode of the electron gun causes it to emit electrons which are then
>> focused into a beam, accelerated and guided by other electrodes. The
>> amount of delection depends on the voltage on the deflection plates.
>> Only an area the (unchanging) diameter of the very thin beam "lights up"
>> as the beam traverses the screen. It's the kinetic energy of the beam
>> which causes this - not an electrical interaction.
>>
>>      http://electronics.howstuffworks.com/question694.htm
>>      http://www.scienceclarified.com/Ca-Ch/Cathode-Ray-Tube.html
>>
>> http://books.google.com/books?
>id=HCXaRo0vRdsC&pg=PA69&lpg=PA69&dq=electron+gun
>+deflection&source=bl&ots=m-
>rky1unrW&sig=nzfCqBZIZf0xGKnWah09MNvnN6M&hl=en&ei=8H-7SrmJKY-
>Ntgevr4XADQ&sa=X&oi=book_result&ct=result&resnum=6#v=onepage&q=electron%
>20gun%20deflection&f=false
>>
>> Electron guns are not limited to CRTs.
>>
>>      http://www2.slac.stanford.edu/vvc/accelerators/electrongun.html
>>      http://www.kimballphysics.com/electron_guns/egun_prod.htm
>>
>> "Joesepi" <JRM@xxxxxxxxxxxx> wrote:
>>
>>>I doubt voltage of the electron emitter  beam has anything to do with
>>>deflection but rather the amount of energy to light up the increased
>>>area of a larger screen in the same amount of time. The voltage on the
>>>deflection plates may need to be higher to change the angle amount.
>>>
>>>I would conclude to get 50, 100 or even 200W of light a fair bit of
>>>energy would be required and therefore a large voltage, also. What was
>>>the enrgy of light output from the ole' CRT screen. I always had about
>>>300W, in mind, for a larger TV set. but only based on rough hearsay from
>>>TV guys.
>>>
>>>
>>>"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
>>>news:4aba5e35.30488687@xxxxxxxxxxxxxxxx
>>>> Well, it's been nearly 50 years since I learned about CRTs but, as I
>>>> dimly recall, higher voltages are required for higher delection of the
>>>> beam so the
>>>> bigger the CRT the higher the voltage. Few B&W TVs had large screens
>>>> so they
>>>> had lower voltages. Since these folks are not deflecting a beam, the
>>>> voltage
>>>> is likely to be much less. And, even if they were deflecting a beam,
>>>> the "screen" size is much, much smaller than a TV.
>>>>
>>>> I asked Vu1 about the internal voltage and whether the bulbs emit
>>>> x-rays and
>>>> got the following (non)response.
>>>>
>>>> "Detail specifications will be made available after independent and UL
>>>> lab testing have completed.  Please refer to our website and blog site
>>>> for current updates."
>>>>
>>>> I do not know whether UL will test for x-rays.
>>>>
>>>> Ian Shef <invalid@xxxxxxxxxxxxx> wrote:
>>>>
>>>>>nobody@xxxxxxxxxxxx (Dave Houston) wrote in
>>>>>news:4ab843ef.65491421@xxxxxxxxxxxxx:
>>>>>
>>>>>> I think that was only for color TVs where the voltage is 32,000
>>>>>> volts. Radiation increases with the voltage. It's not likely that
>>>>>> these lights will have anywhere near that voltage - not if they are
>>>>>> going to fit existing fixtures.
>>>>>
>>>>>The TVs get the same line voltage that these bulbs get.  Also, high
>>>>>voltage
>>>>>supplies can be made quite tiny if the current is low and if the
>>>>>environment
>>>>>suppresses arcing.
>>>>>
>>>>>While I agree that these bulbs are likely to be safe, I think that the
>>>>>issue
>>>>>bears scrutiny.  Trust, but verify!
>>>>
>>>>