Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > alt.folklore.computers > #154802 > unrolled thread

History--did relay logic (e.g. crossbar switch) need air conditioning?

Back to article view | Back to alt.folklore.computers

Contents

  History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-04 19:44 -0800
    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Quadibloc <jsavard@ecn.ab.ca> - 2015-12-04 22:19 -0800
    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Jon Elson <elson@pico-systems.com> - 2015-12-05 13:27 -0600
    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? jhhaynes@earthlink.net - 2015-12-07 13:41 -0800
      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-07 17:58 -0800
        Re: History--did relay logic (e.g. crossbar switch) need air conditioning? JimP <solosam90@gmail.com> - 2015-12-07 21:31 -0600
          Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Dave Garland <dave.garland@wizinfo.com> - 2015-12-07 23:27 -0600
            Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-07 22:12 -0800
              Re: History--did relay logic (e.g. crossbar switch) need air conditioning? "Osmium" <r124c4u102@comcast.net> - 2015-12-08 07:24 -0600
                Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-08 14:01 +0000
              Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-08 20:21 +0000
                Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-08 12:40 -0800
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Lawrence Statton <lawrence@senguio.mx> - 2015-12-08 15:31 -0600
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-09 01:04 +0000
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Dave Garland <dave.garland@wizinfo.com> - 2015-12-08 21:23 -0600
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Joy Beeson <jbeeson@invalid.net.invalid> - 2015-12-08 22:40 -0400
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Dave Garland <dave.garland@wizinfo.com> - 2015-12-09 00:46 -0600
                        Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Andrew Swallow <am.swallow@btinternet.com> - 2015-12-09 07:04 +0000
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-09 09:15 +0000
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-09 18:27 +0000
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? "Ranger" <r5432@gmail.com> - 2015-12-10 15:39 +1100
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? "Rod Speed" <rod.speed.aaa@gmail.com> - 2015-12-10 15:35 +1100
                Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Andrew Swallow <am.swallow@btinternet.com> - 2015-12-09 06:59 +0000
                Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Bernd Felsche <berfel@innovative.iinet.net.au> - 2015-12-09 23:47 +0800
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-09 17:20 +0000
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Michael LeVine <mlevinespmfltr@redshift.com> - 2015-12-09 10:14 -0800
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-09 10:21 -0800
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-09 18:47 +0000
                        Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Morten Reistad <first@last.name.invalid> - 2015-12-09 21:33 +0100
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Jon Elson <jmelson@wustl.edu> - 2015-12-11 16:56 -0600
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-09 18:27 +0000
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? mausg@mail.com - 2015-12-09 20:47 +0000
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? "Osmium" <r124c4u102@comcast.net> - 2015-12-09 17:01 -0600
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? mausg@mail.com - 2015-12-10 10:48 +0000
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Bernd Felsche <berfel@innovative.iinet.net.au> - 2015-12-10 10:52 +0800
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? scott@slp53.sl.home (Scott Lurndal) - 2015-12-10 14:15 +0000
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Anne & Lynn Wheeler <lynn@garlic.com> - 2015-12-10 10:02 -0800
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-10 10:17 -0800
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? hancock4@bbs.cpcn.com - 2015-12-09 13:10 -0800
                    Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Bernd Felsche <berfel@innovative.iinet.net.au> - 2015-12-10 11:22 +0800
                      Re: History--did relay logic (e.g. crossbar switch) need air conditioning? mausg@mail.com - 2015-12-10 10:53 +0000
                        Re: History--did relay logic (e.g. crossbar switch) need air conditioning? JimP <solosam90@gmail.com> - 2015-12-10 17:54 -0600
                  Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Lawrence Statton <lawrence@senguio.mx> - 2015-12-09 17:17 -0600
            Re: History--did relay logic (e.g. crossbar switch) need air conditioning? JimP <solosam90@gmail.com> - 2015-12-08 10:03 -0600
              Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-08 20:21 +0000
                Re: History--did relay logic (e.g. crossbar switch) need air conditioning? "J. Clarke" <j.clarke.873638@gmail.com> - 2016-01-02 15:32 -0500
        Re: History--did relay logic (e.g. crossbar switch) need air conditioning? Lon <lon.stowell@comcast.net> - 2015-12-13 12:58 -0700

Page 1 of 3  [1] 2 3  Next page →

#154802 — History--did relay logic (e.g. crossbar switch) need air conditioning?

A writeup of a Bell No. 5 crossbar central office installation of 
1960 states that a/c was included "to maintain cleanliness and 
humdity control as required for the crossbar equipment".

Would anyone know if air conditioning was required for postwar 
relay logic installations?

The Bell crossbar switch was developed and first deployed in the
1930s (No. 1 crossbar, crossbar-tandem).  I don't think central
offices in the 1930s had a/c.  No. 5 crossbar came out after WW II.

Before crossbar, other Bell switching systems dating to the 1920s
had extensive relay logic, but I strongly doubt there was any
air conditioning--it would be too expensive and a/c was too new.

Indeed, I thought the first use of a/c in a telco exchange was
for electronic switching, where the tubes and circuits kicked off
a lot of heat.

Also, railroad switching towers after the 1930s widely used relay
logic, some of it rather sophisticated, and I don't think the towers
or outdoor huts had a/c.

[public replies, please]

[toc] | [next] | [standalone]

#154803

Vacuum tubes produced a lot of heat, but they were also fairly tolerant of heat.

Relays have coils, and the long wires in them would have had resistance, so 
they would produce some heat as well. But again, they would be pretty tolerant 
of heat, it would take a very hot environment before the heat would make them 
cease to function properly.

It's transistors, as we know, that are very easily damaged by too much heat.

Cleanliness, though, would include removing dust from the air. This would 
prevent open circuits. And excessive humidity could lead to short circuits. So 
"cleanliness and humidity control" sound like legitimate considerations for 
relay equipment - particularly if it happens to be designed to tight tolerances.

Early relay equipment in telegraph offices wouldn't be like that. But crossbar 
switches likely did stretch relay technology to its limits, so I don't see the 
article as being too odd, even if the use of air conditioning for relays was 
novel.

John Savard

[toc] | [prev] | [next] | [standalone]

#154811

hancock4@bbs.cpcn.com wrote:

> A writeup of a Bell No. 5 crossbar central office installation of
> 1960 states that a/c was included "to maintain cleanliness and
> humdity control as required for the crossbar equipment".
> 
> Would anyone know if air conditioning was required for postwar
> relay logic installations?
I believe that they were surprised by the dust sensitivity of the crossbar 
swtching system.  The older rotary selector switches were self-wiping, and 
didn't need much attention in that department.  As the crossbar did much 
less of the wiping action, they tended to get noisy contacts.  You could 
always tell when you were on a crossbar switch, as there were these bell-
like "bonging" noises when the crossbar was switching other circuits in the 
same frame.  Eventually they had to go in and clean the contacts.

Jon

[toc] | [prev] | [next] | [standalone]

#154849

I spent some of my childhood hanging around a step-by-step office.  As I recall
it was not air-conditioned at first, but air conditioning was added later.  This
was in the South where it gets hot in the summer.  But I doubt air conditioning
was used in electromechanical offices until maybe the late 1950s when it became
used a lot more in all kinds of buildings in the area. 

At first there was a procedure where they would curtain off an aisle of
switches, attach a big vacuum blower with a dirt bag on the output at one
end.  Then go in with a compressed air gun and blow the dirt off the bank
contacts.  Later this was discontinued - I think they learned that blowing
all that dust around caused more problems than it solved.  There were manual
bank cleaning tools, a set of curved fingers with cloth sleeving fitted over
them.

Quite possibly air conditioning did help to stabilize the atmosphere in the
switch room, besides making it more comfortable in summer.

[toc] | [prev] | [next] | [standalone]

#154853

On Monday, December 7, 2015 at 4:42:00 PM UTC-5, jhha...@earthlink.net wrote:

> Quite possibly air conditioning did help to stabilize the atmosphere in the
> switch room, besides making it more comfortable in summer.

Step-by-step switchgear was very durable and did not require a/c.
But the mfr did suggest sealing the unit in dirty or humid
conditions.

While air conditioning was developed about 100 years ago, I think 
it become practical and cost-effective to use in commercial 
buildings after WW II. (Before that it was mostly used in 
specialized situations; though I think the White House, 
State Dept, and Pentagon got a/c during WW II.  In 1939, a luxury
housing development had it.)

Anyway, I suspect most initial a/c installations were done for the
equipment in a room, not for the people.

[toc] | [prev] | [next] | [standalone]

#154854

On Mon, 7 Dec 2015 17:58:39 -0800 (PST), hancock4@bbs.cpcn.com wrote:
>On Monday, December 7, 2015 at 4:42:00 PM UTC-5, jhha...@earthlink.net wrote:
>
>> Quite possibly air conditioning did help to stabilize the atmosphere in the
>> switch room, besides making it more comfortable in summer.
>
>Step-by-step switchgear was very durable and did not require a/c.
>But the mfr did suggest sealing the unit in dirty or humid
>conditions.
>
>While air conditioning was developed about 100 years ago, I think 
>it become practical and cost-effective to use in commercial 
>buildings after WW II. (Before that it was mostly used in 
>specialized situations; though I think the White House, 
>State Dept, and Pentagon got a/c during WW II.  In 1939, a luxury
>housing development had it.)
>
>Anyway, I suspect most initial a/c installations were done for the
>equipment in a room, not for the people.

First ones I saw about 1952 were in movie theaters and one church.
-- 
JimP.

[toc] | [prev] | [next] | [standalone]

#154856

On 12/7/2015 9:31 PM, JimP wrote:
> On Mon, 7 Dec 2015 17:58:39 -0800 (PST), hancock4@bbs.cpcn.com wrote:
>> On Monday, December 7, 2015 at 4:42:00 PM UTC-5, jhha...@earthlink.net wrote:
>>
>>> Quite possibly air conditioning did help to stabilize the atmosphere in the
>>> switch room, besides making it more comfortable in summer.
>>
>> Step-by-step switchgear was very durable and did not require a/c.
>> But the mfr did suggest sealing the unit in dirty or humid
>> conditions.
>>
>> While air conditioning was developed about 100 years ago, I think 
>> it become practical and cost-effective to use in commercial 
>> buildings after WW II. (Before that it was mostly used in 
>> specialized situations; though I think the White House, 
>> State Dept, and Pentagon got a/c during WW II.  In 1939, a luxury
>> housing development had it.)
>>
>> Anyway, I suspect most initial a/c installations were done for the
>> equipment in a room, not for the people.
> 
> First ones I saw about 1952 were in movie theaters and one church.
> 
The banners said "Come On In, It's Cool Inside!"

[toc] | [prev] | [next] | [standalone]

#154857

On Tuesday, December 8, 2015 at 12:28:11 AM UTC-5, Dave Garland wrote:

> The banners said "Come On In, It's Cool Inside!"

I think movie theatres got a/c pretty early, as a way to attract 
customers.  Also, it made practical sense as windows were impractical
in a movie house.

Some buildings used crude a/c systems, such as blocks of ice and 
fans.  Trains used ice blocks for many years, both passenger and 
refrigerated freight.  Station crews would load fresh ice into
hatches.  Of ourse, people had "ice boxes" in their
homes before electric refrigerators.

I think the old methods had merit until modern refrigerants came 
along.  Before Freon, I think they had to use noxious chemicals 
(ammonia?) in machine refrigeration.

I don't know the technology, but steam and natural gas can somehow
be used to create cooling.  In the 1960s, I remember the gas works 
pushing people to get gas air conditioners.

In the 1960s, apparently the price of a window a/c unit came 
down enough that lots of people and small stores got them.  
But often house wiring had to be upgraded 'cause those things 
used a lot of power.

[toc] | [prev] | [next] | [standalone]

#154861

<hancock4@bbs.cpcn.com> wrote:

> Some buildings used crude a/c systems, such as blocks of ice and
> fans.  Trains used ice blocks for many years, both passenger and
> refrigerated freight.  Station crews would load fresh ice into
> hatches.  Of ourse, people had "ice boxes" in their
> homes before electric refrigerators.
>
> I think the old methods had merit until modern refrigerants came
> along.  Before Freon, I think they had to use noxious chemicals
> (ammonia?) in machine refrigeration.

Before Freon, home refrigerators used sulphur dioxide and methyl chloride. I 
believe ammonia was used for commercial installations such as grocery 
stores.

Sulphur dioxide was also used as a fumigant to kill insects, nasty stuff.  I 
don't know what other properties methyl chloride has.

On my first trip to the UK, in the late 60's, one thing I noticed was the 
relative lack of air conditioning compared to the US. In general I thought 
London was like a time machine. 

[toc] | [prev] | [next] | [standalone]

#154865

On Tue, 8 Dec 2015 07:24:36 -0600
"Osmium" <r124c4u102@comcast.net> wrote:

> On my first trip to the UK, in the late 60's, one thing I noticed was the 
> relative lack of air conditioning compared to the US. In general I
> thought London was like a time machine. 

	Air conditioning is still quite rare in the UK - with the climate
round here there's little point. Good insulation and efficient heating are
far more useful.

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
C:>WIN                                      | A better way to focus the sun
The computer obeys and wins.                |    licences available see
You lose and Bill collects.                 |    http://www.sohara.org/

[toc] | [prev] | [next] | [standalone]

#154877

On 2015-12-08, hancock4@bbs.cpcn.com <hancock4@bbs.cpcn.com> wrote:

> I think the old methods had merit until modern refrigerants came 
> along.  Before Freon, I think they had to use noxious chemicals 
> (ammonia?) in machine refrigeration.

Ironically, Freon is now considered a noxious chemical as well.

> I don't know the technology, but steam and natural gas can somehow
> be used to create cooling.  In the 1960s, I remember the gas works 
> pushing people to get gas air conditioners.

Propane fridges were popular for trailers and RVs (and might still
be for all I know).  I still find this paradoxical.

> In the 1960s, apparently the price of a window a/c unit came 
> down enough that lots of people and small stores got them.  
> But often house wiring had to be upgraded 'cause those things 
> used a lot of power.

And that became a whole new problem...

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  HTML will DEFINITELY be ignored.  Join the ASCII ribbon campaign!

[toc] | [prev] | [next] | [standalone]

#154878

On Tuesday, December 8, 2015 at 3:22:10 PM UTC-5, Charlie Gibbs wrote:
 
> Propane fridges were popular for trailers and RVs (and might still
> be for all I know).  I still find this paradoxical.

I don't know the technology, but trailers used to haul refrigerated
goods now have a self-powered unit on them to provide cooling.
Maybe it's a tiny gas turbine to run the a/c compressor, but I'm
not sure.


> > In the 1960s, apparently the price of a window a/c unit came 
> > down enough that lots of people and small stores got them.  
> > But often house wiring had to be upgraded 'cause those things 
> > used a lot of power.
> 
> And that became a whole new problem...

IIRC, the houses on our block had only 60 amp service when built
(stove, water, heat, dryer were all gas).  Without a/c, that
was adequate for lighting, some appliances, TV, etc.  Each room
had one 15 amp outlet, on circuits shared with other rooms.
there was no dishwasher or disposal.

The ktichen light was three 20 watt fluorescent lamps.

The dining room chandiler was quite bright, with five lamps.
I think we put in 40W bulbs, that was plenty.  (Or, we
might have used 3 60W bulbs and left two dark.)

When people got an early a/c, it was 110V and 15 amp, so nothing
else could be used on that particular circuit, and things
like toasters couldn't be used.

Later a/c units ran on 220V, but that required a 220V outlet,
which had to be installed.

The power company pushed people to upgrade to "100 amp" service,
and many did.  It was nicer in that fuses didn't have to be
purchased and replaced and people could run their a/c as they
needed, but it was pretty expensive. Today it would be a must have, 
as people would probably have more than one window unit, 
plus a computer, more TV sets, more appliances, etc.

Heck, one 15 amp outlet per room probably would be inadequate
today and the whole house would need rewiring.  Also, 60 year
old wiring probably has bad insulation, though I think back
then they used the cables with the metal cladding.

[toc] | [prev] | [next] | [standalone]

#154880

hancock4@bbs.cpcn.com writes:
> I don't know the technology, but trailers used to haul refrigerated
> goods now have a self-powered unit on them to provide cooling.
> Maybe it's a tiny gas turbine to run the a/c compressor, but I'm
> not sure.

Little diesel engines ... "The Usual Suspects" are Isuzu, Kubota, and
Mitsubishi.  

[toc] | [prev] | [next] | [standalone]

#154883

On 2015-12-08, hancock4@bbs.cpcn.com <hancock4@bbs.cpcn.com> wrote:

> IIRC, the houses on our block had only 60 amp service when built
> (stove, water, heat, dryer were all gas).

Our house, which was built in 1958, had 60-amp service.  When we
renovated we upgraded - partly because it was good to have the
extra juice, but also because our insurance company refused to
renew us unless we did.  All the wiring was being redone anyway,
so it was no big deal.  In fact, when we checked with Hydro we
found that it was only another $300 to upgrade to 200-amp service,
so we went whole hog.

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  HTML will DEFINITELY be ignored.  Join the ASCII ribbon campaign!

[toc] | [prev] | [next] | [standalone]

#154885

On 12/8/2015 2:40 PM, hancock4@bbs.cpcn.com wrote:
> On Tuesday, December 8, 2015 at 3:22:10 PM UTC-5, Charlie Gibbs wrote:
>  
>> Propane fridges were popular for trailers and RVs (and might still
>> be for all I know).  I still find this paradoxical.
> 
> I don't know the technology, but trailers used to haul refrigerated
> goods now have a self-powered unit on them to provide cooling.
> Maybe it's a tiny gas turbine to run the a/c compressor, but I'm
> not sure.
> 
> 
>>> In the 1960s, apparently the price of a window a/c unit came 
>>> down enough that lots of people and small stores got them.  
>>> But often house wiring had to be upgraded 'cause those things 
>>> used a lot of power.
>>
>> And that became a whole new problem...
> 
> IIRC, the houses on our block had only 60 amp service when built
> (stove, water, heat, dryer were all gas).  Without a/c, that
> was adequate for lighting, some appliances, TV, etc.  Each room
> had one 15 amp outlet, on circuits shared with other rooms.
> there was no dishwasher or disposal.
> 
> The ktichen light was three 20 watt fluorescent lamps.
> 
> The dining room chandiler was quite bright, with five lamps.
> I think we put in 40W bulbs, that was plenty.  (Or, we
> might have used 3 60W bulbs and left two dark.)
> 
> When people got an early a/c, it was 110V and 15 amp, so nothing
> else could be used on that particular circuit, and things
> like toasters couldn't be used.
> 
> Later a/c units ran on 220V, but that required a 220V outlet,
> which had to be installed.
> 
> The power company pushed people to upgrade to "100 amp" service,
> and many did.  It was nicer in that fuses didn't have to be
> purchased and replaced and people could run their a/c as they
> needed, but it was pretty expensive. Today it would be a must have, 
> as people would probably have more than one window unit, 
> plus a computer, more TV sets, more appliances, etc.
> 
> Heck, one 15 amp outlet per room probably would be inadequate
> today and the whole house would need rewiring.  Also, 60 year
> old wiring probably has bad insulation, though I think back
> then they used the cables with the metal cladding.

60 years ago was 1955. They had Romex wiring, IIRC plastic insulation
on the wires, some sort of composite fibrous (paper?) cable sleeve.
I'm not sure what you're thinking about with the "metal cladding",
though conduit was (and still is) used where mechanical protection is
required, and there is flexible conduit made out of helical metal
("greenfield" or "armored cable").

My house was built before electricity (there are gas jets in the walls
for lamps). The wiring was probably done in the 1920s or 1930s, and
the remaining original parts is individual lengths of wire (no cable)
insulated with some sort of impregnated fabric (and now very brittle)
material and fabric sleeves, soldered splices wrapped with friction
tape. Not knob & tube (wires run between ceramic insulators, and with
ceramic tubes where they went through surfaces), another old technique.

But frankly, other than the kitchen (fridge and sometimes one electric
cooking device) and pantry (microwave, toaster, coffeemaker, toaster
oven, rice cooker, don't use more than one at a time), there's no room
that would need 15 amps (the furnace blower and the washing machine
would be the only large consumers). I didn't choose to live in a
climate that required A/C (I have a window unit, but often don't get
around to putting it in), and today's computers and TVs don't pull
very much power. Most of the lighting is CFL or LED, aside from places
where the light might only be "on" for 2 minutes (and LEDs are getting
cheap enough for those) or where actual dimming (or other triac
control, like photocell or solid-state timer) might be important (IMHO
neither "dimmable" CFLs nor LEDs work very well).

I need (and have) more than one outlet per room, but that's what power
strips are for. All those wall warts don't add up to a lot of amps,
though.

[toc] | [prev] | [next] | [standalone]

#154886

On Tue, 8 Dec 2015 21:23:52 -0600, Dave Garland
<dave.garland@wizinfo.com> wrote:

> (IMHO
> neither "dimmable" CFLs nor LEDs work very well).

I have a dimmable LED light on my sewing machine that works very well.
It has eight LEDs and you can turn on two, four, or all eight.  But
I've never seen this feature on mains-power lights.  Pity; if you had
enough LEDs that size to illuminate a room, you'd have reasonably-fine
control over the brightness.

-- 
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

[toc] | [prev] | [next] | [standalone]

#154889

On 12/8/2015 8:40 PM, Joy Beeson wrote:
> On Tue, 8 Dec 2015 21:23:52 -0600, Dave Garland
> <dave.garland@wizinfo.com> wrote:
> 
>> (IMHO
>> neither "dimmable" CFLs nor LEDs work very well).
> 
> I have a dimmable LED light on my sewing machine that works very well.
> It has eight LEDs and you can turn on two, four, or all eight.  But
> I've never seen this feature on mains-power lights.  Pity; if you had
> enough LEDs that size to illuminate a room, you'd have reasonably-fine
> control over the brightness.
> 
I suspect the answer is that the triac-type dimmers used in houses
(which operate by chopping AC to reduce the total power available)
aren't compatible with the physics of how LEDs or CFLs work. The
incandescent bulb is a quintessentially analog device, if you throttle
the power it will dim in proportion. Your sewing machine probably
actually switches how many LEDs are powered. We need a solution that
doesn't require rewiring houses.

Maybe that could be done with room lights by having the switching
controlled in the LED bulb by RMS(?) voltage. (CFLs are a more
intransigent case.) But AFAIK nobody produces those bulbs yet.

[toc] | [prev] | [next] | [standalone]

#154891

On 09/12/2015 06:46, Dave Garland wrote:
> On 12/8/2015 8:40 PM, Joy Beeson wrote:
>> On Tue, 8 Dec 2015 21:23:52 -0600, Dave Garland
>> <dave.garland@wizinfo.com> wrote:
>>
>>> (IMHO
>>> neither "dimmable" CFLs nor LEDs work very well).
>>
>> I have a dimmable LED light on my sewing machine that works very well.
>> It has eight LEDs and you can turn on two, four, or all eight.  But
>> I've never seen this feature on mains-power lights.  Pity; if you had
>> enough LEDs that size to illuminate a room, you'd have reasonably-fine
>> control over the brightness.
>>
> I suspect the answer is that the triac-type dimmers used in houses
> (which operate by chopping AC to reduce the total power available)
> aren't compatible with the physics of how LEDs or CFLs work. The
> incandescent bulb is a quintessentially analog device, if you throttle
> the power it will dim in proportion. Your sewing machine probably
> actually switches how many LEDs are powered. We need a solution that
> doesn't require rewiring houses.
>
> Maybe that could be done with room lights by having the switching
> controlled in the LED bulb by RMS(?) voltage. (CFLs are a more
> intransigent case.) But AFAIK nobody produces those bulbs yet.
>
Alternatively just have a data link between the lamp switch and the LED 
lamp. I have seen wifi used to control LED dimers but that is expensive.

[toc] | [prev] | [next] | [standalone]

#154893

On Tue, 08 Dec 2015 22:40:38 -0400
Joy Beeson <jbeeson@invalid.net.invalid> wrote:

> On Tue, 8 Dec 2015 21:23:52 -0600, Dave Garland
> <dave.garland@wizinfo.com> wrote:
> 
> > (IMHO
> > neither "dimmable" CFLs nor LEDs work very well).
> 
> I have a dimmable LED light on my sewing machine that works very well.
> It has eight LEDs and you can turn on two, four, or all eight.  But

	That's neat.

> I've never seen this feature on mains-power lights.  Pity; if you had
> enough LEDs that size to illuminate a room, you'd have reasonably-fine
> control over the brightness.

	My entire house is lit with 5050 LED strips (I have a 12V system
and flush tracks with the strips held on magnetically) - there are 225
individual LEDs in this room (about 60W it's quite a big room and I like it
bright). But there's no way to control the LEDs individually. They could be
switched in sets of three but the wiring would be horrendous.

	I have a PWM dimmer coming for one room, it will be interesting to
see how well it works and how much RFI it generates.

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
C:>WIN                                      | A better way to focus the sun
The computer obeys and wins.                |    licences available see
You lose and Bill collects.                 |    http://www.sohara.org/

[toc] | [prev] | [next] | [standalone]

#154908

On 2015-12-09, Dave Garland <dave.garland@wizinfo.com> wrote:

> (IMHO neither "dimmable" CFLs nor LEDs work very well).

Recently I went to a lighting supplier for some other things,
and while there I played with one of their LED dimmer demo units.
I managed to get it to flicker.  Looks like I'll be staying with
my halogens for a while longer, at least on dimmed circuits.

I am replacing our ubiquitous PAR20 halogens with LEDs on non-dimmed
circuits.  Even more beneficial than the reduction of per-fixture
power from 50 watts to 7 is the fact that the LEDs run cool; the
halogens run so hot that they've melted plastic parts in some of
the fixtures, and occasionally one will unsolder its internal wiring.

CFLs are a non-starter.  I have a couple but have relegated them to
outdoor use; I find their light to be too dreadful to use indoors.

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  HTML will DEFINITELY be ignored.  Join the ASCII ribbon campaign!

[toc] | [prev] | [next] | [standalone]

Page 1 of 3  [1] 2 3  Next page →

Back to top | Article view | alt.folklore.computers

csiph-web