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Author Topic: Low pressure sodium lamps now hard to find.  (Read 877 times)
bobm
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« Reply #15 on: September 28, 2020, 08:26:40 pm »

Swindon currently is currently 6 months into an 18 month program to change all its lights. Not only the saving on electricity but in changing lamps.  When I was last involved in street lighting (ok so 40 years ago now but the SON was the modern technology then) lamps needed changing every 2 years. 

My area of Swindon was converted a couple of years ago.  There have been complaints they are too bright but, despite having one outside my bedroom window, I have not had a problem with them.
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stuving
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« Reply #16 on: September 28, 2020, 10:27:48 pm »

Swindon currently is currently 6 months into an 18 month program to change all its lights. Not only the saving on electricity but in changing lamps.  When I was last involved in street lighting (ok so 40 years ago now but the SON was the modern technology then) lamps needed changing every 2 years. 

My area of Swindon was converted a couple of years ago.  There have been complaints they are too bright but, despite having one outside my bedroom window, I have not had a problem with them.

I find that surprising. My impression (and other's comments) is that they are as bright close to, but leave unlit areas between them. The actual light source is bright if you look at it, but more directional, hence the narrower beam to keep direct light out of drivers' (and walkers') eyes. So you need more of them - which rather defeats part of the reason for putting them in. 
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« Reply #17 on: September 29, 2020, 07:24:00 am »

Swindon currently is currently 6 months into an 18 month program to change all its lights. Not only the saving on electricity but in changing lamps.  When I was last involved in street lighting (ok so 40 years ago now but the SON was the modern technology then) lamps needed changing every 2 years. 

My area of Swindon was converted a couple of years ago.  There have been complaints they are too bright but, despite having one outside my bedroom window, I have not had a problem with them.

Many local authorities use lamps that switch to a reduced Lux level over night (I think 23:30 to 06:00 or thereabouts).  Many stations use lamps that have PIR sensors on sections of the platforms where the lamps run at reduced Lux levels and switch to the higher level when movement is detected.

I feel its peoples perception that LED lights are brighter due to the LED colour temperature range between 4500oK and 6400oK (oK = degrees Kelvin) typically SON are 2000oK and MBFU 3200oK  Normal daylight is around 5000oK.   Also as  stuving has mentioned the LED street lights are a more focused light that that offered by a SON, MBFU or SOX fitting.

LED lights have drastically reduced the levels of light pollution, I can clearly see stars in the night sky without them being masked by a hideous orange glow
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bobm
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« Reply #18 on: September 29, 2020, 08:15:32 am »

Many stations use lamps that have PIR sensors on sections of the platforms where the lamps run at reduced Lux levels and switch to the higher level when movement is detected.

I have been at Pewsey Station at night and seen a "wave" of light follow a non stopping train along the platform as each column detects the train.

I find that surprising. My impression (and other's comments) is that they are as bright close to, but leave unlit areas between them. The actual light source is bright if you look at it, but more directional, hence the narrower beam to keep direct light out of drivers' (and walkers') eyes. So you need more of them - which rather defeats part of the reason for putting them in. 

I was a bit surprised - but it made the Swindon Advertiser and Radio 2!

Quote
PROBLEMS with new LED street lights shining into people's bedrooms became a hot topic on Jeremy Vine's Radio 2 show.

The Adver first covered the complaints caused by the borough council's ?6.9 million scheme to replace 28,000 orange street lights with money-saving energy-efficient LED lanterns.

Helena Williams Bowie from Penhill Drive told us about how the brighter lights were affecting her sleep and that of her light-sensitive husband John.

She then discussed the issue live on-air with Jeremy Vine and Coun Maureen Penny live on Radio 2 yesterday.

Helena said: "They were so bright it was like Wembley Stadium. The blackout curtains will be a short-term solution to an ongoing problem."

When Helena posted about her problem on a Facebook community group, she got mixed responses. One person said the lights were 'brighter than the sun' - a phrase Jeremy Vine emphasised throughout the radio segment.

Mr Vine asked Coun Penny if the lights could be dimmed and suggested that everyone misses the old orange lights.

Coun Penny replied: "We dimmed the lights in Mrs Williams Bowie's street last Friday and have undertaken further work yesterday to optimise the brightness so that it's set at a siginficantly lower rate at night time.

"I'm really sorry that she has been experiencing these problems. We have only had two complaints and we were expecting some complaints but it's important that we change over to these LED lights."

Mrs Bowie added: "It's a matter of knowing how to complain. The lights have dimmed a bit but the light is still affecting our house.
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Godfrey Tables
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« Reply #19 on: September 29, 2020, 12:20:33 pm »

I predict that in the future, ultra modern LED streetlights would have a beam pattern that could be controlled in software.
With one LED cluster behind carefully configured optics, different parts of said cluster could be controlled remotely depending on which part of the optics are to be lit. Besides flexibility in application, any complaints about unwanted light spill, and the offending sub-cluster of LEDs could be shut off remotely, without the need of an engineer to visit with paint.
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rogerw
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« Reply #20 on: September 29, 2020, 05:34:22 pm »

I had a street light outside the kitchen window (1st floor) in my Trowbridge flat. With the street lighting engineer as a neighbour it was used as a trial for LED lights so that he could monitor it easily. Because the LED gave a more directed light it didn't light my kitchen as well as the previous SON unit. I have replaced tungsten bulbs in my house and, despite being  of a lower equivalent wattage, they appear brighter as the light is very white
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Red Squirrel
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« Reply #21 on: September 29, 2020, 06:13:59 pm »

A pedantic friend of mine refused to refer to old-style light bulbs as such; he called them 'heat bulbs'. His logic was hard to fault; an incandescent bulb converts 90% of the input energy into heat, and barely 10% into light...
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« Reply #22 on: September 29, 2020, 08:36:01 pm »

Many local authorities use lamps that switch to a reduced Lux level over night (I think 23:30 to 06:00 or thereabouts). 

In my street the lights switch off completely between 1am - 5am. If you need the loo during the night and see streetlights, you know it'll soon be time to get up.
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Bmblbzzz
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« Reply #23 on: September 29, 2020, 09:50:32 pm »

Many stations use lamps that have PIR sensors on sections of the platforms where the lamps run at reduced Lux levels and switch to the higher level when movement is detected.

I have been at Pewsey Station at night and seen a "wave" of light follow a non stopping train along the platform as each column detects the train.
Sounds entertaining! And good sense too. I've heard that some streetlamps are being so equipped but it seems to be a very rare thing so far.
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« Reply #24 on: September 29, 2020, 10:16:59 pm »

Got the PIR LED lights at Christchurch too thought here at Hinton Admiral the platform lights stay on all night and the footpath lights dont come on at all!
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Red Squirrel
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« Reply #25 on: September 29, 2020, 11:04:30 pm »

Am I allowed to wheel out my Dad's old story of returning from Pensford to Brislington one summer's evening?

5 minutes before the train rolled in, a chap in railway uniform rolled up, whistling, on his bicycle. He lit the lamps, the train stopped, Dad and his brother got on, and as the train pulled out of the station they saw the man snuffing out the lights. Most economical.
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broadgage
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« Reply #26 on: September 29, 2020, 11:06:05 pm »

Many local authorities use lamps that switch to a reduced Lux level over night (I think 23:30 to 06:00 or thereabouts). 

In my street the lights switch off completely between 1am - 5am. If you need the loo during the night and see streetlights, you know it'll soon be time to get up.

This is becoming more popular. It was tried in years gone by but then found little favour since a special and expensive time control was needed, these were rather complex to set and often set incorrectly.
These days, lighting for part of the night is easy by means of a "part night photocell" these are simple and require no setting up or programing.
They turn the light on at dusk, and off at midnight or such other time as may be specified, and then turn on again at 06-00, or such other time as may be specified, only if still dark.

These units automatically detect local midnight, they "know" that local midnight is half way between dusk and dawn, and of course that 01-00 is an hour after midnight.
When first put into use they turn on all night for the first few nights whilst they "learn" the time. They generally calculate local midnight on a rolling average basis as being half way between the average times of dusk and dawn for the previous week or so.
This maintains reasonable accuracy even if the light is turned on at noon one day due to a solar eclipse.

The drawback is that in most cases the times of operation cant be altered. They may be specified for whatever hours are wanted, but cant later be altered, except by replacing the photocell.
Also they calculate the LOCAL time of midnight and do not normally compensate for changes between summer time and GMT.
(A new version is under development, that DOES adjust for when we change the clocks. The photocell knowns when it is midsummer (shortest night) and also knows that the clocks go back XX days after midsummers day. It also knows when it is midwinter, and knows that clocks go forward YY days after midwinter)
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stuving
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« Reply #27 on: September 29, 2020, 11:24:21 pm »

I predict that in the future, ultra modern LED streetlights would have a beam pattern that could be controlled in software.
With one LED cluster behind carefully configured optics, different parts of said cluster could be controlled remotely depending on which part of the optics are to be lit. Besides flexibility in application, any complaints about unwanted light spill, and the offending sub-cluster of LEDs could be shut off remotely, without the need of an engineer to visit with paint.

I suspect that exists - but deployment may depend on communications. But then soon every street lamp is going have a 5G nanocell built in, isn't it? That's not a new story, by the way - it was around before I retired in 2013 (and I had my own proposal ten years earlier for local positioning transponders...).

Here's one quote:
Quote
One of Ubicquia?s products is its Ubimetro small cell, which can be mounted onto existing streetlights. Aaron claims the Ubimetro for streetlights is a better option than deploying small cells onto new cellular poles or onto cable strands.
and here's another:
Quote
HKT is exploring the possibility to deploy small cells on lampposts. There are around 226,200 lamps in the HK Public Lighting System. Distance between two lamp posts is approx 30 ? 60 meters; typical distance is 50 meters or less. Each Small Cell / AAU covers up to 150 ? 180m in one direction.  Target is to install two Small Cells / AAUs on a lamp post. This way there is only a need to install the small cell on every sixth lamp post to achieve a continuous coverage.

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TonyK
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« Reply #28 on: September 30, 2020, 08:41:55 am »

I would imagine that somewhere, a line will need to drawn between cost and benefit. I am sure it will be possible soon, if it isn't already, to have lights that dim when no-one is around, self-adjust the times to match local conditions, and make disco patterns for New Years Eve. If the lighting is using under 10W of power, though, these refinements aren't saving much energy, and thus add expense without helping much.
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Bmblbzzz
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« Reply #29 on: September 30, 2020, 10:56:01 am »

Following on from the part night photocells Broadgage mentions, it would be clever if they learnt not only when the clocks change but which day of the week it is, so they can keep the lights on longer for the Friday/Saturday night revellers. 
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Tuesday had come down through Dundrum and Foster Avenue, brine-fresh from sea-travel, a corn-yellow sun-drench that called forth the bees at an incustomary hour to their bumbling.
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