Re: VU1 ESL bulbs with HA dimmers?

[nobody@xxxxxxxxxxxx (Dave Houston)]

This is getting interesting. Today's NYT has an article on a new 60W
equivalent LED bulb from Philips that has the same color as a 60W
incandescent. It doesn't say anything about heat, power factor or
compatibility with existing dimmers and, while it has no specific cost
numbers, indicates it _might_ eventually sell for $20-25. (That may be
wishful thinking.)

     http://www.nytimes.com/2009/09/25/technology/25bulb.html?hp

I especially liked this paragraph about the Energy Department...

"At first, the department set no standards for compact fluorescent bulbs and
inferior products flooded the market. Consumers rebelled against the bulbs?
shortcomings: the light output from compact fluorescent bulbs was cold and
unpleasant, their life was much shorter than claimed, many were large and
undimmable, they would not work in cold environments and they contained
polluting mercury."

They didn't note that many of the CFLs also put out about half as much light
as claimed, even when new. But, otherwise, they made most of the points that
I made here when the big push for CFLs first began. Of course, when they
outlaw CFLs, Wall Mart will make out yet again.

nobody@xxxxxxxxxxxx (Dave Houston) wrote:

>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!
>>>>>
>>>>>