From peter at ecoluxint... Sat Feb 8 01:59:49 2003
From: peter at ecoluxint... (peter)
Date: Fri, 7 Feb 2003 17:59:49 -0800
Subject: [Darksky]Phase Cut Dimming of LED traffic signal.
Message-ID: <007f01c2cf15$c6182850$1501a8c0@TWO>
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Hello All list members ;
I am the Director of Engineering at Ecolux International in Thailand. =
Just found and signed up to your good list while surfing. Native NY'er.
There are some list questions about dimming of LED traffic signals. =
Most LED traffic signals use a switching power supply (for line =
isolation and high energy efficiency) to convert 220V/120VAC to 12V or =
similar low voltage to drive the LED's. This power supply does not =
respond well to phase cut dimming. That's why most (but not all) LED =
signals are not dimmable using ordinary phase cut dimming. Then =
normally 3 or 4 LED's are wired in series with one current limiting =
resistor (depending on the voltage drop of the LED's. Voltage for green =
is much higher than red). Super bright LED's last a long time if the =
circuit is properly designed (MTBF > 2,000,000 hours at room =
temperature), and this power supply normally is the limiting factor for =
the MTBF (Mean Time Before Failure) of the traffic signal.
We manufacture a line of traffic signals that are dimmable using =
ordinary phase cut dimmers. These signals do not use a power supply. =
They respond well to phase cut dimming. The only problem you might =
experience is that most triacs in even a small dimmer control are rated =
600 watts or more. Now in simple terms, the triac is normally pulsed =
to switch it to the "on" condition. Then it is held conducting (on) by =
load current. Since an LED traffic light only uses 4-5 watts, the low =
load current may not keep the triac on reliably. This results in severe =
and unacceptable flicker at dimmed settings. One solution (don't laugh) =
is to use another load (like a big power resistor), to hold the triac =
on. Of course this eliminates the benefit of power savings for the LED =
signal, so clearly not recommended. The recommended method is to use a =
dimmer rated for very small loads.
We also do automatic night time dimming by photocell sensor and dimming =
solar flashers. Most of our sales are 220V, but we are starting to get =
120V orders. Our signals lack regulatory approval, which you may need =
(Thailand has no regulatory requirements yet). So just thought you =
might like to know that dimming is very possible. Lots of info, =
reliability info, and specs on our web site. I hope this post is not =
too commercial. Moderator feel free to cut.
Best Regards,
Peter Guagliano
Director of Engineering
Ecolux International Co. Ltd.
www.ecoluxint.com
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Hello All list members ;
I am the Director of Engineering at =
Ecolux=20
International in Thailand. Just found and signed up to your good =
list=20
while surfing. Native NY'er.
There are some list questions about =
dimming of LED=20
traffic signals. Most LED traffic signals use a switching power=20
supply (for line isolation and high energy efficiency) to =
convert=20
220V/120VAC to 12V or similar low voltage to drive the LED's. This =
power=20
supply does not respond well to phase cut dimming. That's why most =
(but=20
not all) LED signals are not dimmable using ordinary phase cut =
dimming. =20
Then normally 3 or 4 LED's are wired in series with one current limiting =
resistor (depending on the voltage drop of the LED's. Voltage for green =
is much=20
higher than red). Super bright LED's last a long time if the =
circuit is=20
properly designed (MTBF > 2,000,000 hours at room temperature), and =
this=20
power supply normally is the limiting factor for the MTBF (Mean =
Time Before=20
Failure) of the traffic signal.
We manufacture a line of traffic =
signals that are=20
dimmable using ordinary phase cut dimmers. These signals do not =
use a=20
power supply. They respond well to phase cut dimming. =
The only problem you might experience is that most =
triacs in=20
even a small dimmer control are rated 600 watts or more. Now in =
simple=20
terms, the triac is normally pulsed to switch it to the "on"=20
condition. Then it is held conducting (on) by load =
current. =20
Since an LED traffic light only uses 4-5 watts, the low load =
current=20
may not keep the triac on reliably. This results in severe =
and=20
unacceptable flicker at dimmed settings. One solution (don't =
laugh) is to=20
use another load (like a big power resistor), to hold the triac =
on. Of=20
course this eliminates the benefit of power savings for the LED =
signal, so=20
clearly not recommended. The recommended method is to use a =
dimmer=20
rated for very small loads.
We also do automatic night time dimming =
by=20
photocell sensor and dimming solar flashers. Most of our =
sales=20
are 220V, but we are starting to get 120V orders. Our =
signals lack=20
regulatory approval, which you may need (Thailand has no regulatory =
requirements=20
yet). So just thought you might like to know that dimming is =
very=20
possible. Lots of info, reliability info, and specs on our web =
site. =20
I hope this post is not too commercial. Moderator feel free =
to=20
cut.
Best Regards,
Peter Guagliano
Director of=20
Engineering
Ecolux International Co. Ltd.
www.ecoluxint.com
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From jhollan at amper....muni.cz Mon Apr 14 13:30:00 2003
From: jhollan at amper....muni.cz (Jan Hollan)
Date: Mon, 14 Apr 2003 14:30:00 +0200 (CEST)
Subject: [Darksky]Re: [magnitude6] International Workshop (fwd)
Message-ID:
---------- Forwarded message ----------
Date: Mon, 14 Apr 2003 13:53:05 +0200
From: Fabio Falchi
Reply-To: magnitude6@yahoogroups...
To: magnitude6@yahoogroups...
Subject: Re: [magnitude6] International Workshop
Dear friends,
I remember to you that from may 1 to 4 the LPIW - Light Pollution International Workshop will be held in Frascati, near Rome. It will be an exceptional possibility to meet and discuss on the LP and, for you that has not yet seen Rome...an occasion to have a nic holiday!
Here you find the preliminary program. For additional info see: http://lpiw.uai.it/
I hope to see you in Frascati.
Fabio Falchi
Unione Astrofili Italiani
CieloBuio
International Dark-Sky Association
LPIW
Light Seminario
Pollution Internazionale
International sull'Inquinamento
Workshop Luminoso
International Training Workshop for Amateur Astronomers and
Lighting Technical Operators for the discussion of the problems linked to Light Pollution and to Lighting Technical Profession.
May 2 - 4, 2003
Frascati (Rome - Italy)
Scuderie Aldobrandini Auditorium
Institutional Sponsorship:
European Union
Italian Prime Ministership
Ministry for the Environment
Ministry for Education, University and Scientific Research
Council of the Regione Lazio
Province of Rome Council
Municipality of Frascati
Requested Co-operations:
Legambiente
W.W.F. Italia
Pro Natura
Società Astronomica Italiana
Official Languages:
English - Italian
Further Information:
http://lpiw.uai.it lpiw@uai...
General Features
Recent technological developments led to a general improvement of living standards for common people. However this process has been accompanied by serious pollution phenomena of the environment due to a disharmonious and seldom sustainable growth of the society, made worse by the unrestrained consumerism and the loss of some fundamental values of culture and environmental defence.
The needs of the decoration of city structure including the lighting of artistic and architectural beauties of our cities, the requirements for public safety together with the lighting of the industrial areas have often carried to an uncontrolled and non eco-sustainable lighting.
The various national and international studies on this subject have underlined that by modifying behavioural rules adopted till now a better kind of lighting and a considerable energy saving could be obtained along with an improvement of the road traffic system and a reduction of light pollution.
Why to organize a International Workshop on Light Pollution
Due to the above, the Union of Italian Amateur Astronomers (UAI), co-operating with the National Coordination for the Safeguard of the Dark Sky (Cielobuio) and the International Dark-Sky Association (IDA) together with the greatest national and international authorities dealing with these problems, organizes an International Workshop for Amateur Astronomers and Lighting Technical Operators with the aim to investigate thoroughly the characteristics of light pollution and the remedial measures to fight it.
In Europe, Italy is in the front line in fighting Light Pollution: many of the Italian Regions and Municipality Administrations had already taken strong measures to contain Light Pollution and consequently to save energy.
Who is the Workshop directed to
The principal aim of the Workshop is to deepen and to investigate all the themes linked to Light Pollution. It will also try to create a new and eco-sustainable lighting-technical culture through the evaluation and the design of high quality and performance lighting devices. The Workshop is directed to all people involved or that could be involved in the campaign against light pollution, in particular:
a.. Astronomers and Amateur Astronomers in order to improve the safeguard of the night sky and of the territory. In fact, they could be an invaluable support for every local situation.
b.. Light-technical experts who could deepen their knowledge in the above mentioned technical and plant-engineering solutions
c.. Members of Municipalities and Public Administrations who could acknowledge the economic, environmental and image benefits linked to an eco-sustainable lighting
d.. Lighting device manufacturers who could deal with new trends and types of lighting plants
e.. Park managers and ecologists who could be involved in controlling light pollution sources and their impact on either environment, flora and fauna
f.. Local, District and Departmental Government Units who handle with territorial management
g.. Lawyers who deal with various rules connected to this problem
h.. Economists surely interested in energy saving
i.. Biologists and Natural Sciences Academics for the heavy impact of light pollution on the living
j.. Doctors interested in health problems caused by too strong lighting sets
k.. Psychologists studying disease connected to an unsuitable use of the light, such as the ones coming from the loss of concentration while driving
l.. Agronomists interested in relations between agricultural production and light
PRELIMINARY PROGRAMME
Thursday, 1st May
5 - 7 p.m. First Meeting of Delegates and Registration
8.30 p.m. Opening Dinner
9 p.m. Conference After Dinner "Disappearing Sky Beauties"
by Bob Gent - European Co-ordinator for The International Dark-Sky Association
"Conti di Tuscolo" Restaurant Via Conti di Tuscolo, 10 Frascati tel. 06.9424899
Friday, 2nd May
Greetings and Discourses from Authorities, Patronage and Co-operator Corporations
Scientific Training
Þ What is Light Pollution
· How it generates
· How it spreads
Þ Previsions for Future Light Pollution
· World Night Sky pollution map
· Light Pollution in Italy
· Light Pollution realistic previsions
Þ Italian Operators
· Cielobuio - UAI - IDA
· Organization
· Co-operation and Agreements
· Operative Structures
· Technical and Scientific Commission on Light Pollution
· Internet
· Mutual Projects
· ISTIL
Environment and Safety - First Part
Þ Ecosystem and Light Pollution
· Effects on the environment
· Effects on human beings
· Effects on flora and fauna
Lighting Technique and Light Pollution - First Part
Þ Basic Physic Dimensions of Lighting Technique
· The Choice of lighting devices
Þ Light Pollution Components and Their Weight
· Direct and Indirect flow
Þ How to fight Light Pollution successfully in ten Steps
· Ten realistic suggestions
Regulations
Þ Italian and European Technical Rules
· UNI 10819
· UNI 10439
· CEI - CEN
Þ Law-making Situation
· District Rules: Basilicata, Campania, Lazio, Marche, Piedmont, Tuscany, Valle d'Aosta and Veneto
· National and regional PDL (Art State)
· Either National Agreements (such as UAI Sun), Regional or Local
Saturday, 3rd May
Environment and Safety - Second Part
Þ Social Effects of Light Pollution - Vision and Safety
· Light and its consequences on night vision
· Road Safety
Þ Social Effects of Light Pollution - Remarks
· Discussion on Highway Code application and on general Rules
Þ Energy Saving
· Practical Example: Frosinone
· Plants re-conversion
Didactic
Þ Didactic Experiences
· Students showing stars
Projects & Technical Lighting
Þ Photometrical and Light Technical Parameters
· Certification of photometrical data
Þ How to measure Light Pollution and Light Technical Parameters
· Measure instruments
· What has to be measured
· Operative techniques
Þ Light technology
· Equipment against Light Pollution
· New generation lamps
· New lighting techniques
Þ Systems to Reduce Lighting Flux
· Flux reducers
· Assets and liabilities of these methods
· Pregnant examples of energy saving
Þ Basic Concepts on How to Measure Lighting Sets
· Basic theories on technical lighting planning
· The part of planners and their professional deontology
Þ Technical Lighting Planning
· Projects with high technical lighting performance
· Planning costs and maintenance: comparisons and controls
Þ Specific Sets Planning
· Lighting sets construction regarding roads, residences, sport and historical places
· Particular Sets
· Technical Lighting objections
Þ The efficient Road Planning
· Save the Sky
· Energy Saving
Þ Lighting Planning
· One example: Monza
Þ Energy Expenditures Reduction
· Only useful lighting
Þ Sustainable Lighting and Conclusions
· Only useful lighting
6.30 - 8.00 p.m.
Public Conference open to Information Media
Round Table with Politicians, Astronomers, Amateur Astronomers, Technical Lighting Experts, moderated by Franco Foresta Martin
Sunday, 4th May
Only for Amateur Astronomers Session - Discussion and Involvement on Territory
Þ The situation of Regional and National Rules with attendance ways
Þ Controls and Actions on their Territory
Þ How to act without Regional Legislation
Þ Behaviour with Institutions regarding LR Applications
Þ Discussion
End of Session awaited by 4.30 p.m.
Registration
There isn't registration Fee for foreign attendants.
English simultaneous translation will be provided for foreign attendants.
Please, send an email for your pre-registration to: lpiw@uai...
CD-ROM on Light Pollution
It will be distributed to all Participants.
It will contain:
· the health condition of our sky
· the main public laws, acts and rules allowing to control light pollution
· useful instructions to help all amateur astronomers to appropriately control the territory correctly
· the principles for non-pollutant lighting device design
General Information
The town of Frascati counts little more than 20,000 inhabitants; it is situated on Roman Castles, more or less 20 km south of Rome.
It can be easily reached from Rome in 20 minutes by using a train shuttle leaving every hour from the FS Railway Station of Roma Termini.
A list containing the main hotels and a city map is available visiting the web site of the Workshop at the address http://lpiw.uai.it
For any further information, please do not hesitate to contact the Organizing Committee writing to lpiw@uai...
[Non-text portions of this message have been removed]
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From jhollan at amper....muni.cz Mon Apr 14 13:32:39 2003
From: jhollan at amper....muni.cz (Jan Hollan)
Date: Mon, 14 Apr 2003 14:32:39 +0200 (CEST)
Subject: [Darksky]Re: [magnitude6] International Workshop (fwd)
Message-ID:
---------- Forwarded message ----------
Date: Mon, 14 Apr 2003 14:22:28 +0200 (CEST)
From: Jan Hollan
To: Jan Hollan
Subject: Re: [magnitude6] International Workshop
Fabio,
I will definitely come for the whole meeting, I can speak on any topic you
would consider as appropriate. Of course, it would be like bringing wood
into the middle of the forest... (a Czech proverb). Perhaps a note on the
even lower influence of the steep-upward going light to the sky luminance,
than your drafts suggest (due to the mostly forward-directed scattering).
I will bring the Cologne (http://www.uni-koeln.de/symposium2002)
proceedings with me, but any main lecture on the health effects should be
given by a doctor of medicine, not by a physicist...
I still try to get some other people to be sent to Frascati by our
Ministry (I hope they will finance my trip), but nobody has responded yet
that she/he would like to attend. I'll try to move the leading Czech
environmental lawyer to come -- the key person who could influence
the future development in our country.
jenik
PS. I'm afraid there has been a deadline already, so consider please this
letter as both my application and its confirmation... I could come for
more days, if it would suit you.
> Dear friends,
> I remember to you that from may 1 to 4 the LPIW - Light Pollution International Workshop will be held in Frascati, near Rome. It will be an exceptional possibility to meet and discuss on the LP and, for you that has not yet seen Rome...an occasion to have a nice holiday!
> Here you find the preliminary program. For additional info see: http://lpiw.uai.it/
> I hope to see you in Frascati.
> Fabio Falchi
From jhollan at amper....muni.cz Mon Apr 14 15:39:00 2003
From: jhollan at amper....muni.cz (Jan Hollan)
Date: Mon, 14 Apr 2003 16:39:00 +0200 (CEST)
Subject: [Darksky]Symposium for Protection of the Night Sky (fwd)
Message-ID:
---------- Forwarded message ----------
Date: Fri, 11 Apr 2003 03:59:32 EDT
From: RLGent1@aol...
To: ida@darksky...
Subject: Symposium for Protection of the Night Sky
Memorandum for all IDA sections and affiliated organizations:
From: International Dark-Sky Association
European Liaison Office
and Symposium Organizing Committee
The 3rd European Symposium on the Protection of the Night Sky will be held in
Stuttgart, Germany, 12-13 September 2003. It will be located at the
Planetarium of Stuttgart, Kepler-Saal.
The program will include internationally acclaimed specialists in protecting
the nighttime environment, and the list of confirmed speakers includes Dr.
David Crawford, co-founding officer of the International Dark-Sky
Association, as well as Mr. Gent, Dr. Haenel, Dr. Wuchterl, Dr. Kerschbaum,
Dr. Posch and other leaders from Europe.
Contributions are expected from many European countries. Recently there has
been much progress as the general public becomes aware of the problems and
solutions of light pollution. Last year, the Parliament of the Czech
Republic passed the first national law to control light pollution, and more
recently, the Hungarian National Railways won an International Lighting Award
for energy conservation and glare reduction at 500 rail stations. These
actions and other international projects will be discussed at this symposium.
All IDA sections and affiliated organizations are warmly invited to
participate. Requests to present papers should be sent to the organizers
listed below. The deadline for submitting papers is 1 June 2003.
Additional information about conference and hotels will be available soon and
sent in subsequent messages. The organizing committee is composed of Dr.
Keller, Mr. Gent, and Dr. Posch. Feel free to distribute this notice widely
and share it with local media and interested parties.
*************************** END
**********************************************
Symposium Contacts:
Prof. Dr. Hans-Ulrich Keller
Carl-Zeiss-Planetarium Stuttgart
Mittlerer Schloßgarten
Willy-Brandt-Straße 25
(Neckarstraße 47)
D-70173 Stuttgart
Tel. + 49 711 162 92 15
nach Dienstschluß + 49 711 162 92 26
http://planetarium.stuttgart.de
Email HUK: HUKPLAN@planetarium....shuttle.de
Or: RLGent1@aol...
IDA European Liaison Officer
Dardago, Italy
Or: posch@astro....ac.at
Astronomy Department University of Vienna
IDA Austria
From jhollan at amper....muni.cz Tue May 13 09:00:10 2003
From: jhollan at amper....muni.cz (Jan Hollan)
Date: Tue, 13 May 2003 10:00:10 +0200 (CEST)
Subject: [Darksky]Dagens Nyheter article
In-Reply-To:
Message-ID:
The article, hardly readable for me (seems I don't understand Swedish...)
is at
URL: http://www.dn.se/DNet/jsp/polopoly.jsp?d=597&a=103009
Title: DN - Nyheter - Himlen mörknar över Brno
(be sure to put the address in parentheses, if copying it on a linux
command line, because of &)
thanks, Karin!
31 Jan 2003 karin.bojs@dn... wrote:
> Dear Jenik Hollan,
>
> Thanks a lot for all your kind assistance during my stay in Brno. Tomorrow,
> Saturday, the story on light pollution will be published, if you like to
> tell your friend in Gothenburg. I send you a copy anyway.
> While waiting, you can se the web version att www.dn.se/vetenskap
From jhollan at amper....muni.cz Tue May 13 09:47:14 2003
From: jhollan at amper....muni.cz (Jan Hollan)
Date: Tue, 13 May 2003 10:47:14 +0200 (CEST)
Subject: [Darksky]Natural Sky Hour (fwd)
Message-ID:
To: david
> I have written to the
> government asking if one day they could have an "astronomy hour" when
> all the street lights are switched off at night for an hour so people
> can see the Milky Way etc! Has this ever been done in your country?
Dave,
thank you for the support. We are still far from achieving any real
change in Czechia, just the notion that light at night is a polluting
substance is becoming to be known a bit, slowly.
I know of no examples of switching off lights to get a less polluted sky.
Just my friends made such a happening once for me, when we've arrived with
my wife into a small village of Hostetin (we work there quite often on
various projects regarding sustainable countryside, but lighting is not
yet included). It was wonderful and convincing, but lasted just a couple
of minutes.
Non-Substantial fraction of communities in Czechia (ten per cent?),
villages and even small towns, switch off public lighting sometimes
between 22:30 and midnight, at least before working days. It surely helps
people who want to see the starry heavens, but has a rather limited use
for children...
cheers, jenik