Re: [Phys-l] CFL's not such a hot idea

[Bernard Cleyet <bernardcleyet@redshift.com>]

Edmiston, Mike wrote:

> Like others stated, I don't typically get the advertised life from a
> CFL.  Part of that might be caused by turning them on and off too often.
> Some recommend CFLs last longest if left on for at least 3 hours at a
> time.  That's a real waste if you don't need them on that long.
>  

the rule I've heard is for TV (w/ kinescope was more true w/ vacuum 
tubes) leave on if watching again w/ in about 1/2 hr.  cycling "ages" 
the heater(s).
Since there are two pair leads to the Hg discharge tube, also heated 
electrodes.

> Although they are not labeled as "burn base down," 

Thought is correct at lest on the ones that have base down printed.  All 
have DRY location.   I just read several, all have:  not in totally 
enclosed fixture.

> I think they last
> longer when installed base-down.  When base-up the heat from the tube
> convects onto the electronics.  I have had CFLs base-up that have only
> lasted a few months.  The high-priced Osram bulbs that are considered
> "industrial" (and they plug into special fixtures) last quite a long
> time in our university buildings.  They are usually base-up, but the
> electronics are in the housing rather than the base of the bulb.  They
> can be on 24/7 and last a couple years.
>
> Overall, I have not found CFLs economical, although the price is coming
> down.  If the Osram bulbs and fixtures were less expensive I would
> consider them.
>
> One reason I've played with CFLs is just to check them out.  I also have
> a plan that my wife thinks is strange, but it makes good sense to me.
> In the fall and winter, if I replace a bulb, I use incandescent because
> there really isn't any wasted heat in the winter. 

so also says the conceptual Physics guy (Hewitt)  w/ a pic. of blazing 
lights in tower office buildgs.

> The light-bulb heat
> just helps heat my house.  If I had a heat pump it would be a different
> story; some heat pumps are getting coefficients of performance (COP)  of
> 3.5 (meaning 3.5 watts of heat for 1 watt of electricity). However, with
> resistive electric heat a watt is a watt.  Or, with natural gas and a
> furnace that is 85%, it was actually less expensive last year to heat
> with resistive electric heaters (or light bulbs).
>
> Then, in spring and summer (when I an running the air conditioner), if I
> replace a bulb I put in a CFL.  There's no need to have the AC and the
> lighting fighting each other any more than necessary.
>
> However, even though it is interesting to experiment, I don't think CFLs
> are going to solve much.  Also, Denker is correct that LEDs are the way
> to go, at least as far as I can see right now.  When LEDs for home
> lighting become convenient and affordable, that's what I will be doing.

As reported earlier our E bill in half by using CFLs only (one 
exception).  Since the gas bill is now about the same as the E bill, we 
reduced are energy cost about one third.

cut

bc, shocked no one has claimed to have dismantled one, thinks if were 
teaching assign exercise to reverse engineer.  A TPT article!

p.s. two TO92 pkg. high power switchers (DK51)


http://www.trktechnology.com/jsyzcn/product5e.html

A torroid and EI  transformer, lotsa caps, etc. on reverse 5 surface 
mounted resistors (I assume.)