lightbulbs
Jerry Natowitz
Couple of questions on light bulbs for you folks out there:
1) What is the spectrum (at least as filtered by the bulb) of the
blue flash that a dying light bulb (or the filament thereof) produces?
As a child I used to think that the bulbs gave off X-rays when they
died (I have no idea where that belief came from).
2) I use Bulbsavers on some of my light bulbs. Bulbsavers are stick-on
thermisters, a device that changes from a high electrical resistance
to a very low resistance when they heat up.
The theory (well proven by my experience) is that the bulbs last longer
because the thermister reduces thermal shock to the filament caused by
the rush of current that normally occurs when turning on a light.
I have read that the light output of "thermistered" bulbs is decreased
even at normal operating temperature and have noticed a "yellow shift"
in the spectrum.
My question is: how much of a decrease in light output do these things
cause and what change in the light spectrum does occur?
BTW, it takes a few seconds for a thermistered bulb to light up. It's
quite funny to see the puzzled reaction of people used to instant light
when they turn one of these suckers on.
--
Yours in hair,
Bear
ihnp4!houxm!hropus!jin
Andrew Koenig
the way, are not thermistors but diodes) are not worth the money.
Reason: light bulbs are less efficient at lower temperatures.
If instead of using a diode you replace the light bulb with one of
lower wattage that gives the same amount of light, the extra efficiency
will save you enough electricity to pay for the light bulb by the
time it burns out.
Bruce T. Lowerre
> thermisters, a device that changes from a high electrical resistance
> to a very low resistance when they heat up.
> The theory (well proven by my experience) is that the bulbs last longer
> because the thermister reduces thermal shock to the filament caused by
> the rush of current that normally occurs when turning on a light.
> I have read that the light output of "thermistered" bulbs is decreased
> even at normal operating temperature and have noticed a "yellow shift"
> in the spectrum.
>
> My question is: how much of a decrease in light output do these things
> cause and what change in the light spectrum does occur?
>
> BTW, it takes a few seconds for a thermistered bulb to light up. It's
> quite funny to see the puzzled reaction of people used to instant light
> when they turn one of these suckers on.
It's not the sudden rush of current that is hard on the filament but the
AC current. I've seen slow motion movies of filaments warming up when
being lit. The alternating magnetic field plus the softening of the
filament as it warms up causes it to do a lot of "break dancing" (excuse
the pun).
Mohan Venkatachalapathy
While we are on lightbulbs - are there any fluoroscent(sp?) lamps that
produce light in almost the same spectral range (that warm yellow glow)
as incandescent bulbs?
Larry Lippman
>
> 1) What is the spectrum (at least as filtered by the bulb) of the
> blue flash that a dying light bulb (or the filament thereof) produces?
> As a child I used to think that the bulbs gave off X-rays when they
> died (I have no idea where that belief came from).
The blue flash from a "dying" lightbulb is actually the momentary
ionization of the argon in the nitrogen-argon fill gas mixture. When the
filament fails, a momentary arc is struck as the pieces fall apart; this
arc results in the ionization. No significant ionization takes place in
a conventional incandescent lamp during normal operation.
There could be a slight grain of truth to the x-ray story. X-rays
are given off when electrons strike a HARD target material - like the
tungsten lamp filament. Most x-ray tubes use anodes (i.e., the target)
which are made of tungsten. It is quite possible that a momentary, miniscule
amount of very _soft_ x-rays would be given off during the brief ionization
which accompanies an incandescent lamp failure. I cannot overemphasize how
brief and miniscule such x-ray emanation might be. Without doing some
calculations, I am not certain if in fact there is enough energy in a 120
volt lamp to create x-rays all - but I would guess there is. Such x-ray
radiation would be modulated at 60 Hz, and chances are only a few cycles would
exist.
> 2) I use Bulbsavers on some of my light bulbs. Bulbsavers are stick-on
> thermisters, a device that changes from a high electrical resistance
> to a very low resistance when they heat up.
> The theory (well proven by my experience) is that the bulbs last longer
> because the thermister reduces thermal shock to the filament caused by
> the rush of current that normally occurs when turning on a light.
> I have read that the light output of "thermistered" bulbs is decreased
> even at normal operating temperature and have noticed a "yellow shift"
> in the spectrum.
>
> My question is: how much of a decrease in light output do these things
> cause and what change in the light spectrum does occur?
There is always some resistance to the thermistor - even when hot -
so the lamp will never see the full line voltage. If you have noticed a
"yellow shift", then the lamps must be operating at a REALLY LOW voltage.
An incandescent lamp behaves like a black body, and hence lamp energy is
measured as "color temperature" - the temperature of an equivalent black
body in degrees Kelvin. Normal household incandescent lamps have color
temperature ratings of 2700 to 3100 degrees K. Lamp operating current
determines color temperature (of a given lamp). It might surprise you to
learn that while operating a _given_ lamp from 2700 to 3100 degrees K.
(by varying current) causes a change in OVERALL radiated energy of almost
50%, the spectral distribution change in the VISIBLE portion (400 to 700
nanometers) is almost nil. Notice that I have not said what happens when
an incandescent lamp is run much below 2700 degrees K.; below that value,
an incandescent lamp becomes extremely inefficient, and will, of course,
show a spectral shift toward red.
In very rough terms - for small values of less than 20% from the
rated value of the lamp - a change in lamp current results in an exact
corresponding change in lamp energy output; i.e., decreasing lamp current by
10% results in roughly 10% less lamp energy (watts). Also for small values
of less than 20%, a change in lamp current results in TWICE the amount of
visible light output; i.e., decreasing lamp current by 10% results in 20%
less visible light output (lumens).
Also, notice that I have been referring to lamp current rather
than lamp voltage. While decreasing lamp voltage decreases lamp current,
it is a non-linear function, and the current is really the parameter which
determines energy output.
==> Larry Lippman @ Recognition Research Corp., Clarence, New York
==> UUCP {bbncca|decvax|rocksanne|rocksvax|watmath}!sunybcs!kitty!larry
==> VOICE 716/688-1231 {rice|shell}!baylor!/
==> FAX 716/741-9635 {G1, G2, G3 modes} seismo!/
==> "Have you hugged your cat today?" ihnp4!/
Larry Lippman
Standard lightbulbs are available in a 130 volt rating, as opposed
to the normal 120 volt rating. Operating a 130 volt lamp at 120 volts does
not appreciably lower the light output, but seems to appreciably increase
lamp life (as compared to 120 volt lamps).
I have used 130 volt lamps in outdoor lights around my house and in
vapor-tight fixtures in my barn for a number of years with excellent results.
These lamps seem to take the thermal shock much better than a 120 volt lamp
(like when an outdoor lamp is turned on at 0 degrees F.). I have also tried
lamps rated as "rough service" lamps, but have had much better luck with
the 130 volt variety for outdoor use. Believe it or not, I have 130 volt
lamps in my barn which are over six years old. I specifically chose the
130 volt lamps for use in guarded, vapor-tight fixtures, because it is a
pain in the you-know-what to change lamps in that type of fixture.
You can get 130 volt lamps from any wholesale electrical supply firm
(which will generally sell to anyone over-the-counter on a cash basis). The
price is about the same as for regular 120 volt lamps.
gor...@cae780.uucp
> Standard lightbulbs are available in a 130 volt rating, as opposed
>to the normal 120 volt rating. Operating a 130 volt lamp at 120 volts does
>not appreciably lower the light output, but seems to appreciably increase
>lamp life (as compared to 120 volt lamps).
> ... I have also tried
>lamps rated as "rough service" lamps, but have had much better luck with
I heartily second the 130v suggestion. The "rough service" bulbs are very
useful too, but not because of longer life in normal service -- they survive
much better in things like garage/workshop extension lights where vibration
and rough handling usually kill the bulbs long before they can burn out.
FROM: Brian G. Gordon, CAE Systems Division of Tektronix, Inc.
UUCP: tektronix!cae780!gordon
{ihnp4, decvax!decwrl}!amdcad!cae780!gordon
{hplabs, resonex, qubix, leadsv}!cae780!gordon
USNAIL: 5302 Betsy Ross Drive/#58137, Santa Clara, CA 95052-8137
AT&T: (408)748-4817 [direct] (408)727-1234 [switchboard]
timo...@tekigm2.uucp
About lightbulbs - Has anyone else besides me measured their line voltage that
comes into their house? I measured mine after several of my lights blew, were
replaced then blew again in what seemed an abnormally short period of time. My
measurment turned up a nominal voltage of 127.5 volts RMS (with a true RMS DVM
made by Beckman). I called the power company, Portland General Electric, and I
got the reponse "This is the normal voltage we set the lines to, to avoid the
chance of brown-outs in the winter time."
I just had to ask myself if PGE's motives were more pocketbook oriented. Quick
calculations say that power usage will increase as the square of the voltage.
What this means is that a lamp rated at 120 volts (when a common line voltage
used to be 117 volts RMS) is being run at 127 volts, thereby reducing its life
expectantcy to approximately 65 to 76 percent of normal (That's right folks, a
5 percent increase in lamp voltage results in 20 percent increase in light out
put and a 30 percent decrease in lamp life).
In lamps, the voltage increase only amounts to about a 2 to 4 percent increase
in current draw, but this increase combined with refridgerators, stoves, Tv's,
and most other appliances, amounts to a * VERY * large increase in overall use
of electricity.
In general, a 5 percent increase in current, with a 5 percent increase in line
voltage will result in a 10 percent increase of wattage.
In simple terms: A lamp running at 120 volts, 1.00 amps = 120 watts
A lamp running at 127 volts, 1.05 amps = 133 watts
OR A 10.8 PERCENT INCREASE IN POWER USAGE !
Not a bad way at all for the utility companies to bolster a shrinking consumer
power usage market. And 99 percent of the people out there (you), are not even
aware that you've been had.
I tried to get PGE to lower the line back to 117 volts, but they refused to do
so because I was also tied to four other houses. When I mentioned the problem
to my neighbors, they all were totally unknowlegeable about AC theory and they
refused to complain along with me, although one did complain about higher than
normal electric bills. The moral - you can't fight PGE !
Oh well, any comments or suggestions are more than welcome.
--
Tim Margeson (206)253-5240
tektronix!tekigm2!timothym @@ 'Who said that?'
PO Box 3500 d/s C1-937
Vancouver, WA. 98665
Paul M Koloc
>In article <10...@kitty.UUCP> la...@kitty.UUCP (Larry Lippman) writes:
>>a 130 volt lamp at 120 volts does not appreciably lower the light output,
>>but seems to appreciably increase lamp life (as compared to 120 volt lamps).
>>variety for outdoor use. ...
>
>I heartily second the 130v suggestion. The "rough service" bulbs are very
Operating the lamps at lower temperatures prevents "excessive
embrittlement and evaporation (burn-out)". But the lower the
temperature the less the light output and luminous efficiency.
Since AC current drives the lamps in such a way that the temperature
spikes at 120 times per second during 60 hertz operation it would be
better to operate them at a very much higher frequency or by
regulated DC. Direct current desk lamps were a kind of fad a
five or six years ago, but they were over driven and used small
auto "tail-light" bulbs. It would seem to me a compact and
EFFICIENT Direct Current device could be made to drive even 120
volt variety bulbs with MORE radiant efficiency and cooler peak
and maybe even average temperatures.
+---------------------------------------------------------+--------+
| Paul M. Koloc, President: (301) 445-1075 | FUSION |
| Prometheus II, Ltd.; College Park, MD 20740-0222 | this |
| {umcp-cs | seismo}!prometheus!pmk; p...@prometheus.UUCP | decade |
+---------------------------------------------------------+--------+
sei...@hammer.uucp
my house, and in my SO's apt. Mine measured 125.6, my SO's measured
122.3. (I used a Fluke model 77 multimeter, not "true" RMS, but
should be accurate, since line voltage is supposed to be sinusoidal.
Hmmm... maybe I should drag a 'scope home and check that too?)
I'm not as worried about the electric bills as what it's doing to
my equipment. Since moving into this house, I've had problems
with my power amplifier and my phone answering machine. (I have
MOVs protecting them from spikes)
PGE is getting a phone call from me later this morning.
Anyone for a class-action suit?
Snoopy
tektronix!tekecs!doghouse.TEK!snoopy
ki...@kestrel.uucp
From: timo...@tekigm2.UUCP (Timothy D Margeson) Newsgroups:
net.consumers,net.sci Date: 22 May 86 19:40:27 GMT Reply-To:
timo...@tekigm2.UUCP (Timothy D Margeson)
Hi,
About lightbulbs - Has anyone else besides me measured their line
voltage that comes into their house? I measured mine after several
of my lights blew, were replaced then blew again in what seemed an
abnormally short period of time. My measurment turned up a nominal
voltage of 127.5 volts RMS (with a true RMS DVM made by Beckman). I
called the power company, Portland General Electric, and I got the
reponse "This is the normal voltage we set the lines to, to avoid
the chance of brown-outs in the winter time."
I just had to ask myself if PGE's motives were more pocketbook
oriented. Quick calculations say that power usage will increase as
the square of the voltage. What this means is that a lamp rated at
120 volts (when a common line voltage used to be 117 volts RMS) is
being run at 127 volts, thereby reducing its life expectantcy to
approximately 65 to 76 percent of normal (That's right folks, a 5
percent increase in lamp voltage results in 20 percent increase in
light out put and a 30 percent decrease in lamp life).
Suspicion is often healthy, but I think misplaced in this case. An
increase in house voltage will not increase power consumption
significantly in the long run. Induction motors usually consume no
more power at a slightly higher voltage than at their nominal (the
power factor decreases) and if they do, they are undersized and they
put out more power than with the nominal voltage, making (eg.) your
refrigerator turn off sooner. Thermostatically controlled heating
devices consume no more power at the higher voltage. Flourescant
light bulbs consume no more power (again, the power factor decreases).
Even incandescant light bulbs will consume no more power at the higher
voltage, because PG&E's customers will find themselves installing
smaller bulbs. Consumers will run non-thermostatic heating devices
such as broilers for a shorter time.
Electronic devices might consume a bit more power depending on power
supply design.
George Robbins
>After reading the previous article, I measured the line voltage in
>my house, and in my SO's apt. Mine measured 125.6, my SO's measured
>122.3. (I used a Fluke model 77 multimeter, not "true" RMS, but
>should be accurate, since line voltage is supposed to be sinusoidal.
>Hmmm... maybe I should drag a 'scope home and check that too?)
>
>Anyone for a class-action suit?
>
>Snoopy tektronix!tekecs!doghouse.TEK!snoopy
Sorry, but the normal tolerance for line voltage is 110-130V, with anything
in 110,115,117,120 thrown in as the nominal value. What you get basically
depends on the cascaded transformer/line losses between your location and
wherever they care to regulate the voltage.
Also, note that while high voltage is very rough on light bulbs (buy those
130V types!), low voltages are rough on motors like those in your refrigerator
and air-conditioner.
If you really think you have a problem, borrow a recording voltmeter and
leave it across the line for a few days. If you have a lot of variation or
nasty spikes, look for a surplus SOLA type ferroresonant regulator to supply
your critical items. Of course you have to put up with the noise and heat
(read effiency < 100% = $$$)...
Amusing Note:
A friend tells me that an electric utility in the Chicago area still
supplies light bulbs as part of it's service. I wonder if they are the same
quality as the kind you buy in the stores...
--
George Robbins - now working with, uucp: {ihnp4|seismo|caip}!cbmvax!grr
but no way officially representing arpa: cbmvax!g...@seismo.css.GOV
Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
Kevin Szabo
This voltage seems okay to me, but we had a problem with low voltage at
our home some time ago (not a brown-out). My father measured the
voltage at 107 - 100 v through the supper hour and complained to the
utilities. They were slow to act but eventually they grudgingly placed
a chart-recorder on our line. After seeing the problem they replaced
our neighbourhood distribution transformer with a big auto-regulating
beast. Unfortunately the voltage stayed low and we had to call the
utility again. They were even slower to act, but after the
line-monitoring and subsequent checking they found that the
auto-regulating transformer had welded itself stuck on its lowest tap
voltage.
Through this we had hoped that our neighbours had also complained but
most didn't realize there was a problem. They had noticed that their
bulbs were dim (replaced them with higher wattages) and their T.V.
picture was too small (called the T.V. repairman) but they didn't make
the connection. As a result the utility often told us that we were the
only ones who were noticing a problem ... the implication being that
there was no problem.
Kevin
--
Kevin Szabo' ihnp4!watmath!watvlsi!ksbszabo (VLSI Group,U of Waterloo,Ont,Can)
Glenn S. Tenney
>If you really think you have a problem, borrow a recording voltmeter and
>leave it across the line for a few days.
I had a similar problem and put a special meter on the line that remembered
low and hi voltages which showed out-of-acceptable readings. When PGE put
a recording meter on the line (before the meter) they found nothing wrong
even though my meter (in the house) still showed a problem. They just said
they're only responsible up to the meter. I guess their recording meter
is so damped that any voltage would look right.
>
>Amusing Note:
>
> A friend tells me that an electric utility in the Chicago area still
>supplies light bulbs as part of it's service. I wonder if they are the same
>quality as the kind you buy in the stores...
Although it has been a long time since I lived in Evanston, I remember
hearing that as recently as a year ago light bulbs were free based on
the amount of your bill.
>--
>George Robbins - now working with, uucp: {ihnp4|seismo|caip}!cbmvax!grr
>but no way officially representing arpa: cbmvax!g...@seismo.css.GOV
>Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
-- Glenn Tenney
UUCP: {hplabs,glacier,lll-crg,ihnp4!ptsfa}!well!tenney
ARPA: well!ten...@LLL-CRG.ARPA Delphi and MCI Mail: TENNEY
As Alphonso Bodoya would say... (tnx boulton)
Disclaimers? DISCLAIMERS!? I don' gotta show you no stinking DISCLAIMERS!
j...@calmasd.uucp
> [line voltage discussion omitted]
> Amusing Note:
>
> A friend tells me that an electric utility in the Chicago area still
> supplies light bulbs as part of it's service. I wonder if they are the same
> quality as the kind you buy in the stores...
It's true. Commonwealth Edison will give you a new bulb for each one you bring
in (replacement policy). They are good bulbs and seem to last at least as
long as you would expect any bulb to last. They are, as I remember, though
in "funny" denominations - i.e. 52W, 70W, etc.
--
These opinions are solely mine and in no way reflect those of my employer.
...{ucbvax|decvax}!sdcsvax!calmasd!jnp John M. Pantone @ GE/Calma San Diego
Eric Black
>In article <2...@cbmvax.cbmvax.cbm.UUCP> g...@cbmvax.UUCP (George Robbins) writes:
>>If you really think you have a problem, borrow a recording voltmeter and
>>leave it across the line for a few days.
>
>I had a similar problem and put a special meter on the line that remembered
>low and hi voltages which showed out-of-acceptable readings. When PGE put
>a recording meter on the line (before the meter) they found nothing wrong
>even though my meter (in the house) still showed a problem. They just said
>they're only responsible up to the meter. I guess their recording meter
>is so damped that any voltage would look right.
I was having problems with high-voltage spikes which were killing the
computer at work near San Jose. A Franklin Electric monitor showed
spikes exceeding 10,000 volts of a few microseconds duration (no wonder
we were frying components -- I'm not talking just crashes here!),
probably caused by starting and stopping of BIG electric motors in some
of the factories nearby. PG&E brought out *their* monitor, not
trusting ours. It was a pen recorder, one of those jobs with the
rotating circular chart. Funny how that pen wouldn't move fast enough
to show any spikes. Their (PG&E's) attitude was that their power was
good enough for all their other customers, their monitor didn't show
any problem, so it was just too bad. We ended up installing a moby
isolation transformer to get rid of common-mode spikes, and an UPS just
as a line filter. We still had occasional unexplained crashes...
--
Eric Black "Garbage In, Gospel Out"
UUCP: {sun,pyramid,hplabs,amdcad}!chronon!eric
Chuck Forsberg WA7KGX
>I had a similar problem and put a special meter on the line that remembered
>low and hi voltages which showed out-of-acceptable readings. When PGE put
>a recording meter on the line (before the meter) they found nothing wrong
>even though my meter (in the house) still showed a problem. They just said
>they're only responsible up to the meter. I guess their recording meter
>is so damped that any voltage would look right.
Possibly you have a bad connection on the neutral wire. If this is the
case, a heavy load on one side of the 220 volt feed will cause the voltage
on the other side to increase. It's really strange to turn on a heater
and see the lights get brighter.
Chuck Forsberg WA7KGX ...!tektronix!reed!omen!caf CIS:70715,131
Author of Professional-YAM communications Tools for PCDOS and Unix
Omen Technology Inc 17505-V NW Sauvie Island Road Portland OR 97231
Voice: 503-621-3406 TeleGodzilla: 621-3746 300/1200 L.sys entry for omen:
omen Any ACU 1200 1-503-621-3746 se:--se: link ord: Giznoid in:--in: uucp
omen!/usr/spool/uucppublic/FILES lists all uucp-able files, updated hourly
Daniel R. Levy
>In article <2...@cbmvax.cbmvax.cbm.UUCP>, g...@cbmvax.cbm.UUCP (George Robbins) writes:
>> A friend tells me that an electric utility in the Chicago area still
>> supplies light bulbs as part of it's service. I wonder if they are the same
>> quality as the kind you buy in the stores...
>It's true. Commonwealth Edison will give you a new bulb for each one you bring
>in (replacement policy). They are good bulbs and seem to last at least as
>long as you would expect any bulb to last. They are, as I remember, though
>in "funny" denominations - i.e. 52W, 70W, etc.
>...{ucbvax|decvax}!sdcsvax!calmasd!jnp John M. Pantone @ GE/Calma San Diego
Note: you have to pay an extra fee per month to get the bulb service; they
aren't free. Also you have to bring your bill in, in person, to get the bulbs;
you can't get the bulbs by mail or delivered by the meter-reader. Thus I have
never signed up for the bulb service (I'm kind of big on fluorescents, anyway,
having replaced the bathroom and kitchen ceiling lamp bulbs in my apartment
with GE Circline(TM) screw-in fluorescent lamps which have proved very good so
far; I'd replace more if they weren't so awkward to put in shade-type lamps and
small wall lamps).
My personal surmise about the odd-wattage bulbs is that they are "high-
efficiency" versions which are supposed to put out as much light as their
standard cousins--like the 52W bulb would be as bright as a 60W standard,
and the 70W bulb would be as bright as a 75W standard, etc. (I've seen
similar wattages sold in supermarkets as "Miser" (sp? tm?) bulbs. Their
average life according to the package is not as great as that for a standard
bulb--I guess because of a hotter filament which puts out more radiation in
the visible spectrum for a given electrical input than a standard bulb does.)
--
------------------------------- Disclaimer: The views contained herein are
| dan levy | yvel nad | my own and are not at all those of my em-
| an engihacker @ | ployer or the administrator of any computer
| at&t computer systems division | upon which I may hack.
| skokie, illinois |
-------------------------------- Path: ..!{akgua,homxb,ihnp4,ltuxa,mvuxa,
vax135}!ttrdc!levy
we...@sdics.uucp
> [ . . . ]
> Their (PG&E's) attitude was that their power was
> good enough for all their other customers, their monitor didn't show
> any problem, so it was just too bad. We ended up installing a moby
> isolation transformer to get rid of common-mode spikes, and an UPS just
> as a line filter. We still had occasional unexplained crashes...
I don't understand. The Uninterruptable Power Supply we
had at the last place I worked (it's still there) effectively
and completely isolated our power sinks from the SDG$E line
power. Never had a problem with power after that -- after
all, we were drawing our power from about 15 car batteries,
which were constantly being recharged from SDG$E power. I
was present at over ten power-outages (including a few
lightning-related ones) and our equipment never even
hiccupped. Our line-monitoring equipment never saw
anything evil on the line, either (though we didn't have
it connected all the time).
So my question is, how can you claim that it must be
PG&E power [which I'm sure is as dirty as you say] when
you have isolated yourself from it with a UPS and you
still have the crashes?
--
Larry West, we...@ucsd.edu
CRASH
WHAT???
I've lived in the Chicago area all my life and never heard of this!
Comm Ed. has what is called 'light bulb service'. For a monthly charge
of around $0.75 you are entitled to four bulbs when you pay your bill
at one of their bill payment centers (usually a hardware store).
Bob
Scott R. Anderson
>> In article <2...@cbmvax.cbmvax.cbm.UUCP>, g...@cbmvax.cbm.UUCP (George Robbins) writes:
>> > A friend tells me that an electric utility in the Chicago area still
>> > supplies light bulbs as part of it's service. I wonder if they are the same
>> > quality as the kind you buy in the stores...
>> It's true. Commonwealth Edison will give you a new bulb for each one you bring
>> in (replacement policy). They are good bulbs and seem to last at least as
>> long as you would expect any bulb to last. They are, as I remember, though
>> in "funny" denominations - i.e. 52W, 70W, etc.
>I've lived in the Chicago area all my life and never heard of this!
>Comm Ed. has what is called 'light bulb service'. For a monthly charge
>of around $0.75 you are entitled to four bulbs when you pay your bill
>at one of their bill payment centers (usually a hardware store).
I haven't heard of any replacement policy either (new bulbs for burnt-out
ones? What a deal!), although we have tried their light bulb service
as described above. My impression was that we went through their bulbs
pretty quickly.
--
Scott Anderson
ihnp4!oddjob!kaos!sra
Eric Black
>In article <2...@chronon.chronon.UUCP> er...@chronon.UUCP (Eric Black) writes:
>> [ . . . ]
>> isolation transformer to get rid of common-mode spikes, and an UPS just
>> as a line filter. We still had occasional unexplained crashes...
>
>I don't understand. The Uninterruptable Power Supply we
>had at the last place I worked (it's still there) effectively
>and completely isolated our power sinks from the SDG$E line
>power. Never had a problem with power after that -- after
>all, we were drawing our power from about 15 car batteries,
>which were constantly being recharged from SDG$E power. I
>So my question is, how can you claim that it must be
>PG&E power [which I'm sure is as dirty as you say] when
>you have isolated yourself from it with a UPS and you
>still have the crashes?
>
Would have been nice...
It was a case of bureaucratic management refusing to approve the
purchase of an UPS ("we don't need to keep running if the power goes
down, you're an R&D shop, not a production environment"). An
obvious case of poor economy, since they spent as much or more on
lost time & productivity, not to mention actually fried hardware.
We did get them to approve a "power line filter". What that turned
out to be was two-thirds of an UPS, i.e. the AC->DC converter, and
the DC->AC inverter. That's not an UPS, as far as they were concerned.
I added one car battery, basically to act as a capacitor or extremely
small temporary energy storage, but they didn't know that.
I would expect that a real UPS would do the job. Sometimes it's a case
of changing the name to protect the innocent... Of course, the batteries
can add up to quite a bit of $$ if you want to be able to do more
than a quick sync and spin down the disks, if you've got nothing but
big washing machines for disks (those mini-Winchesters are sure nice!).
Joseph S. D. Yao
> ... It would seem to me a compact and
>volt variety bulbs with MORE radiant efficiency and cooler peak
>and maybe even average temperatures.
Is this an old message spat back by another machine, or is this
really coming around again? These devices exist. They're called
diodes. Simple (not full-wave) diodes packaged in discs to go at
the bases of light bulbs are available from almost all cheap mail
order catalogues, or at your corner electric hardware store. The
mail order calls them "Light Savers" and charges ~ $2.50 per.
[Yes, diodes still spike @ 60/sec; but they do save the bulb life.
Maybe the "Light Saver II" has a full-wave rectifier or an LC
smoother in it. I've never cracked one; I was told a long time
ago what was sposed to be in it.]
--
Joe Yao hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}
js...@hadron.COM (not yet domainised)