can 12v solar street light gives same light as 40v tube light gives?
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Ritesh Parikh
Dec 21, 2010, 1:12:41 AM12/21/10
to Green-India: India's Energy Future and Sustainable Living
can 12v led gives same light as 40v tubelight?
KEPLSolarLEDs
Dec 21, 2010, 4:37:14 AM12/21/10
to green...@googlegroups.com
Today's LEDs like Kwality PolyWa LEDs Have efficacy of
100Lumens per watt, which is 25 % higher than the tubelights.
In certain applications where the task area is right underneath the light as in case of Office cabins, the directional property of LEDs gives an advantage of another 20%. giving you a net of 50% additional lux delivery at the point of task area.
A well made 28Watt lamp can substitute a 40W Tubelight with choke.
In certain applications where the task area is right underneath the light as in case of Office cabins, the directional property of LEDs gives an advantage of another 20%. giving you a net of 50% additional lux delivery at the point of task area.
A well made 28Watt lamp can substitute a 40W Tubelight with choke.
Best regards Rajesh S / Madhavi (Team kwality) +91-92462 27946. Kwality Photonics P Ltd ISO9001-2000, India's Pioneer & Largest Manufacturer of LEDs since 22years 29, Electronic Complex, Kushaiguda, Hyderabad 500062 India http://www.kwalityindia.com sa...@kwalityindia.com +91-40-27123555, 27136252, +91-9246227946, 9000081171, 9391017046 Visit us at B02-Lighting South Asia, BEC, Mumbai,Sept14-16. Visit us at B01-LED Expo, Pragati Maidan, Delhi ,Dec 17-19. Visit us at 2-M18--EFY Expo, Pragati Maidan, Delhi, Feb 17-19.
On 21-12-2010 11:42, Ritesh Parikh wrote:
can 12v led gives same light as 40v tubelight?
--
K.C.K.ARYA GUPTA KWALITY ELECTRICALS P LTD 3-6-145/9, HMAYATNAGAR, HYDERABAD 500029 INDIA WWW.LEDECOLIGHT.COM
K.C.K.ARYA GUPTA KWALITY ELECTRICALS P LTD 3-6-145/9, HMAYATNAGAR, HYDERABAD 500029 INDIA WWW.LEDECOLIGHT.COM
deepak kelkar
Dec 21, 2010, 4:47:26 AM12/21/10
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Actually I need more information on lumens and lux. this is same as kw plant and kwh output. In reality it is lux that matters more than lumens. Am I correct ?
--
Deepak Kelkar
Director
Square Engineering Pvt Ltd.
Pune
Cell: 9422310250
Deepak Kelkar
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Deepak Kelkar
Director
Square Engineering Pvt Ltd.
Pune
Cell: 9422310250
BHAVANI PALAPARTHI
Dec 21, 2010, 5:59:10 AM12/21/10
to green...@googlegroups.com
Yes.In reality lux matters more than lumens.Lumens is the measure of what a light emits as light energy and lux is
| a unit of illumination equal to 1 lumen per square metre(1metre lengthX1metre width) If light angle is poor and optics are poor, lux levels may come down and hence we should measure and then compare. But to answer what Ritesh has asked, definitely 12W LED can give equivalent or better light output than a 4 feet florescent tube light.But remember tube light gives light spread in 360deg angle and it would be ideal to demand from LED at least 180deg light angle and currently OSRAM is the only one company giving this much light angle and all others play around lenses,mirror optics etc to be close to this light angle. Hope this clarifies. BHAVANI PALAPARTHI |
Nitin Phansalkar
Dec 21, 2010, 6:44:04 AM12/21/10
to green...@googlegroups.com
Theoretically yes; however practically (considering price and usage) 28W T5 type tube lights are much better than 12W LED. They are brighter than 40W electromagnetic choke fitted / 36W Electronic Choke fitted tube lights and I believe brighter than 12W LED (apart from spread angle).
So if you are thinking of a replacement of a 40W tube then 28W T5 fluorescent tube is the best choice.
HTH
From: BHAVANI PALAPARTHI <bpv...@gmail.com>
To: green...@googlegroups.com
Sent: Tue, 21 December, 2010 4:29:10 PM
Subject: Re: [Green-India] can 12v solar street light gives same light as 40v tube light gives?
So if you are thinking of a replacement of a 40W tube then 28W T5 fluorescent tube is the best choice.
HTH
Regards,
Nitin
Nitin Phansalkar
Owner - SMEfocus Solutions
Coordinator - DESERTEC-India
From: BHAVANI PALAPARTHI <bpv...@gmail.com>
To: green...@googlegroups.com
Sent: Tue, 21 December, 2010 4:29:10 PM
Subject: Re: [Green-India] can 12v solar street light gives same light as 40v tube light gives?
KEPLSolarLEDs
Dec 21, 2010, 7:19:27 AM12/21/10
to green...@googlegroups.com
Dear Deepak,
Thanks for asking the question and giving me an opportunity to explain the fine differences among the colloquially used units of Light.
Lumens is total Light Flux.
Lumens is the total amount of light power as felt by the human eye ( Human eye has a unique response curve for different wavelengths, highest for green and lowest for red & blues.) and expressed in lumnes rathaer than milliwatts/watts. It has to be measured using an Integrating sphere to collect the light in all directions of space.
Lumens is fixed value of any light source, its an invariable. Rest of the optical units are a function of geometry and spatial parameters and can be manipulated using external optical components. Such other parameters are:
Luminous Intensity - Iv - is lumens emanating from unit solid angle and expressed in lumens per steradian or candelas (Cd) / milli candelas (mcd)
In LEDs we can control the divergence of the beam by way controlling the shape of the transparent encapsulant cap., from say 5 degrees to 170 degrees. and also as lambertian to focussed to batwing types etc.
Brightness of a source ( of large surface area like CRT or LCD monitor ) is lumens emanating from unit surface area and expressed in lumens per sq meter or cm2 - NITS or Ft lamberts.
The last but most widely useful quantity is Illuminance. It is the lumens falling on a unit area - Lux ( lumens per cm2). it is also most easy to measure and read with simple detector based meter.
The error or difference in readings arises generally out of the quality of the detector's spectral response curve. A 2-5% variation matching the detector to eye-curve will result in errors bigger than 20%. Other errors are due to spurious reflections from surroundings and variation in reflectivity and quality of nor specular reflection in the apparatus.
Lux of a given Lumen source is generally varies as 1/(distance)2. So the lux level at 2M will be half of the illuminance at 1M.
Please find a small ppt primer on the above.
Vijay Gupta
KWALITY PHOTONICS P LTD , HYDERABAD 500029 INDIA
WWW.LEDECOLIGHT.COM
Thanks for asking the question and giving me an opportunity to explain the fine differences among the colloquially used units of Light.
Lumens is total Light Flux.
Lumens is the total amount of light power as felt by the human eye ( Human eye has a unique response curve for different wavelengths, highest for green and lowest for red & blues.) and expressed in lumnes rathaer than milliwatts/watts. It has to be measured using an Integrating sphere to collect the light in all directions of space.
Lumens is fixed value of any light source, its an invariable. Rest of the optical units are a function of geometry and spatial parameters and can be manipulated using external optical components. Such other parameters are:
Luminous Intensity - Iv - is lumens emanating from unit solid angle and expressed in lumens per steradian or candelas (Cd) / milli candelas (mcd)
In LEDs we can control the divergence of the beam by way controlling the shape of the transparent encapsulant cap., from say 5 degrees to 170 degrees. and also as lambertian to focussed to batwing types etc.
Brightness of a source ( of large surface area like CRT or LCD monitor ) is lumens emanating from unit surface area and expressed in lumens per sq meter or cm2 - NITS or Ft lamberts.
The last but most widely useful quantity is Illuminance. It is the lumens falling on a unit area - Lux ( lumens per cm2). it is also most easy to measure and read with simple detector based meter.
The error or difference in readings arises generally out of the quality of the detector's spectral response curve. A 2-5% variation matching the detector to eye-curve will result in errors bigger than 20%. Other errors are due to spurious reflections from surroundings and variation in reflectivity and quality of nor specular reflection in the apparatus.
Lux of a given Lumen source is generally varies as 1/(distance)2. So the lux level at 2M will be half of the illuminance at 1M.
Please find a small ppt primer on the above.
Vijay Gupta
KWALITY PHOTONICS P LTD , HYDERABAD 500029 INDIA
WWW.LEDECOLIGHT.COM
On 21-12-2010 15:17, deepak kelkar wrote:
Actually I need more information on lumens and lux. this is same as kw plant and kwh output. In reality it is lux that matters more than lumens. Am I correct ?
Deepak Kelkar
On Tue, Dec 21, 2010 at 3:07 PM, KEPLSolarLEDs <gup...@kwalityindia.com> wrote:
Today's LEDs like Kwality PolyWa LEDs Have efficacy of 100Lumens per watt, which is 25 % higher than the tubelights.
In certain applications where the task area is right underneath the light as in case of Office cabins, the directional property of LEDs gives an advantage of another 20%. giving you a net of 50% additional lux delivery at the point of task area.
A well made 28Watt lamp can substitute a 40W Tubelight with choke.
On 21-12-2010 11:42, Ritesh Parikh wrote:can 12v led gives same light as 40v tubelight?
BHAVANI PALAPARTHI
Dec 21, 2010, 7:54:31 AM12/21/10
to green...@googlegroups.com
Agree with Nitin upto some extent on cost economics.But please go for OSRAM/GE/PHILIPS make T5 tubes only for better results and good electronic choke is a must.If not you may burn fingers with Taiwan make T5lamps/Fittings
BHAVANI PALAPARTHI
KEPLSolarLEDs
Dec 21, 2010, 9:22:09 AM12/21/10
to green...@googlegroups.com
Bhavani garu,
Your ref: "it would be ideal to demand from LED at least 180deg light angle and currently OSRAM is the only one company giving this much light angle and all others play around lenses,mirror optics etc to be close to this light angle"
You have made very interesting comments on Index of merit for the LEDs !
a) Angle of distribution of LED would not be issue of superiority of a LED but a choice of parameter.
LUMENs value and efficacy is alone the index of merit for LED.
In LEDs the light emanates from point source which is chip of 1mm size or multiples of such chips. During encapsulation of this chip its very easy to control the light distribution pattern by changing the shape for molding, which is not really cost effective in other light sources.
Its a routine matter that Same rated LED are made with 3 or 4 types of primary Lenses and cater to different industrial needs. Narrow angle good for a accent light and flood light may not be good for a small room. LED light once produced , is capable of being bent in any direction with no extra cost by controlling the package.
For example, the Kwality make PolyWa LEDs are made with Lambertian pattern for general purposes.
While, PolyWa OVAL, A new design recently launched for the street lighting segment has a complex encapsulation to give a oval throw of 80 x 135 degree.While Normal LEDs give a circular illumination and light is wasted beyond the footpath as we go higher to cover more length of the road. Yet the dark spots between the poles and the hot spot underneath the pole is quite an usual sight.
This PolyWa OVAL LED serves to transfer the light that fall beyond the footpaths to where it is needed, namely, to the dark areas between the poles. Further the problem of hot spot( high brightness spot) directly under the pole is also eliminated by another design intervention- ie by cutting the axial light intensity by 50%. Result is highly homogeneous lighting along the road from pole to pole.
b) ALL BRANDs have large view angle products since long time. And all LEDs have visibility beyond the stated view angle, and this visibility is just below 50% of the axial value, and still serves the intended objective of lighting the far corners.
I would opine that all the top brands of LEDs like LumiLEDs, Cree, Nichia, Osram, Seoul, including us the KWALITY POLYWA would fall in the single band with very little to choose from when it comes to issues critical the user- Lumens per dollar and reliability. The brand you named certainly falls somewhere ahead of center in the above mentioned group , yet each one of us has some thing that others don't have or chose not to offer.
Hope I have not over explained and bored you with known facts !
Vijay Gupta 9000081171
Kwality Photonics P Ltd
www.kwalityindia.com sa...@kwalityindia.com
Your ref: "it would be ideal to demand from LED at least 180deg light angle and currently OSRAM is the only one company giving this much light angle and all others play around lenses,mirror optics etc to be close to this light angle"
You have made very interesting comments on Index of merit for the LEDs !
a) Angle of distribution of LED would not be issue of superiority of a LED but a choice of parameter.
LUMENs value and efficacy is alone the index of merit for LED.
In LEDs the light emanates from point source which is chip of 1mm size or multiples of such chips. During encapsulation of this chip its very easy to control the light distribution pattern by changing the shape for molding, which is not really cost effective in other light sources.
Its a routine matter that Same rated LED are made with 3 or 4 types of primary Lenses and cater to different industrial needs. Narrow angle good for a accent light and flood light may not be good for a small room. LED light once produced , is capable of being bent in any direction with no extra cost by controlling the package.
For example, the Kwality make PolyWa LEDs are made with Lambertian pattern for general purposes.
While, PolyWa OVAL, A new design recently launched for the street lighting segment has a complex encapsulation to give a oval throw of 80 x 135 degree.While Normal LEDs give a circular illumination and light is wasted beyond the footpath as we go higher to cover more length of the road. Yet the dark spots between the poles and the hot spot underneath the pole is quite an usual sight.
This PolyWa OVAL LED serves to transfer the light that fall beyond the footpaths to where it is needed, namely, to the dark areas between the poles. Further the problem of hot spot( high brightness spot) directly under the pole is also eliminated by another design intervention- ie by cutting the axial light intensity by 50%. Result is highly homogeneous lighting along the road from pole to pole.
b) ALL BRANDs have large view angle products since long time. And all LEDs have visibility beyond the stated view angle, and this visibility is just below 50% of the axial value, and still serves the intended objective of lighting the far corners.
I would opine that all the top brands of LEDs like LumiLEDs, Cree, Nichia, Osram, Seoul, including us the KWALITY POLYWA would fall in the single band with very little to choose from when it comes to issues critical the user- Lumens per dollar and reliability. The brand you named certainly falls somewhere ahead of center in the above mentioned group , yet each one of us has some thing that others don't have or chose not to offer.
Hope I have not over explained and bored you with known facts !
Vijay Gupta 9000081171
Kwality Photonics P Ltd
www.kwalityindia.com sa...@kwalityindia.com
On 21-12-2010 16:29, BHAVANI PALAPARTHI wrote:
Yes.In reality lux matters more than lumens.Lumens is the measure of what a light emits as light energy and lux is
a unit of illumination equal to 1 lumen per square metre(1metre lengthX1metre width)
If light angle is poor and optics are poor, lux levels may come down and hence we should measure and then compare.
But to answer what Ritesh has asked, definitely 12W LED can give equivalent or better light output than a 4 feet florescent tube light.But remember tube light gives light spread in 360deg angle and it would be ideal to demand from LED at least 180deg light angle and currently OSRAM is the only one company giving this much light angle and all others play around lenses,mirror optics etc to be close to this light angle.
Hope this clarifies.
BHAVANI PALAPARTHI
On Tue, Dec 21, 2010 at 3:17 PM, deepak kelkar <squar...@gmail.com> wrote:
Actually I need more information on lumens and lux. this is same as kw plant and kwh output. In reality it is lux that matters more than lumens. Am I correct ?
Deepak Kelkar
On Tue, Dec 21, 2010 at 3:07 PM, KEPLSolarLEDs <gup...@kwalityindia.com> wrote:
Today's LEDs like Kwality PolyWa LEDs Have efficacy of 100Lumens per watt, which is 25 % higher than the tubelights.
In certain applications where the task area is right underneath the light as in case of Office cabins, the directional property of LEDs gives an advantage of another 20%. giving you a net of 50% additional lux delivery at the point of task area.
A well made 28Watt lamp can substitute a 40W Tubelight with choke.
Best regards Rajesh S / Madhavi (Team kwality) +91-92462 27946
. Kwality Photonics P Ltd ISO9001-2000, India's Pioneer Manufacturer of LEDs since 22years 29, Electronic Complex, Kushaiguda, Hyderabad 500062 India
BHAVANI PALAPARTHI
Dec 25, 2010, 10:26:38 AM12/25/10
to green...@googlegroups.com
Guptaji,
Sorry for late response as I was more busy on solar!
I have anticipated this response either from you or somebody! Enclosed please find 4photos taken from different angles of LED street light installation wherein 2 brands LEDs have been used of same wattage.
Whether you believe it or not,when we asked feedback of a security guard(thinking any one of us in the team may give biased feedback towards a particular brand), we have got a perfect answer.
Now if you can tell us any one of our members in the forum can identify the impressive luminary out of 2 in these 2photos, they can choose that brand LEDs without any hesitation.
I will let you know all the brands after hearing responses from at least 5members.If somebody is seriously interested, I can even take to the site for first hand look to understand more about what light angle can make a difference while choosing LED lighting!
Looks like solving a puzzle but its that worth who is seriously considering LED lighting applications!
BHAVANI PALAPARTHI
--
vishwas bhat
Dec 26, 2010, 9:03:42 AM12/26/10
to green...@googlegroups.com
LED2 looks better to me
KEPLSolarLEDs
Dec 26, 2010, 1:22:07 PM12/26/10
to green...@googlegroups.com
You may be right if the one of the light is judged as better than
other by the users on the spot.
It may be reflectors, the top covers and the optics may be of low loss and lumen output of the LED may be higher due lower operating temperature resulting from better thermal design.
The correlation to view angle to brightness is still very low, by any calculation though.
Yes, I could volunteer to visit the site and help to identify more accurate reasons for better performance, so that these could be replicated for benefit of later installations.
Vijay Gupta
It may be reflectors, the top covers and the optics may be of low loss and lumen output of the LED may be higher due lower operating temperature resulting from better thermal design.
The correlation to view angle to brightness is still very low, by any calculation though.
Yes, I could volunteer to visit the site and help to identify more accurate reasons for better performance, so that these could be replicated for benefit of later installations.
Vijay Gupta
Kwality Photonics P Ltd
ISO9001-2000, India's Pioneer Manufacturer of LEDs since 22years 29, Electronic Complex, Kushaiguda, Hyderabad 500062 Indiahttp://www.kwalityindia.com sa...@kwalityindia.com +91-40-27123555, 27136252, +91-9246227946, 9000081171, 9391017046 Visit us at B02-Lighting South Asia, BEC, Mumbai,Sept14-16. Visit us at B01-LED Expo, Pragati Maidan, Delhi ,Dec 17-19. Visit us at 2-M18--EFY Expo, Pragati Maidan, Delhi, Feb 17-19
On 25-12-2010 20:56, BHAVANI PALAPARTHI wrote:
Guptaji,
Sorry for late response as I was more busy on solar!I have anticipated this response either from you or somebody! Enclosed please find 4photos taken from different angles of LED street light installation wherein 2 brands LEDs have been used of same wattage.
BHAVANI PALAPARTHI
Dec 26, 2010, 10:23:12 AM12/26/10
to green...@googlegroups.com
Voting Response:
LED2-1 LED1-0
4 more to go before announcing the brand and more info in this regard.
BHAVANI PALAPARTHI
Sainath Gupta
Dec 26, 2010, 11:37:05 AM12/26/10
to Green-India: India's Energy Future and Sustainable Living
Reg: LIGHT ANGLE DOES MATTER IN LED LIGHTING pics
I think better photos would have been better, since LED2 is focusing
on cam itself, But if i think LED 1 is better.
On Dec 26, 7:03 pm, vishwas bhat <vishwas...@gmail.com> wrote:
> LED2 looks better to me
>
> On Sat, Dec 25, 2010 at 8:56 PM, BHAVANI PALAPARTHI <bpv...@gmail.com>wrote:
>
> > Guptaji,
>
> > Sorry for late response as I was more busy on solar!
>
> > I have anticipated this response either from you or somebody! Enclosed
> > please find 4photos taken from different angles of LED street light
> > installation wherein 2 brands LEDs have been used of same wattage.
>
> > Whether you believe it or not,when we asked feedback of a security
> > guard(thinking any one of us in the team may give biased feedback towards a
> > particular brand), we have got a perfect answer.
>
> > Now if you can tell us any one of our members in the forum can identify the
> > impressive luminary out of 2 in these 2photos, they can choose that brand
> > LEDs without any hesitation.
>
> > I will let you know all the brands after hearing responses from at least
> > 5members.If somebody is seriously interested, I can even take to the site
> > for first hand look to understand more about what light angle can make a
> > difference while choosing LED lighting!
>
> > Looks like solving a puzzle but its that worth who is seriously considering
> > LED lighting applications!
>
> > BHAVANI PALAPARTHI
>
>
> >>>> Today's LEDs like Kwality PolyWa LEDs Have *efficacy *of 100Lumens
I think better photos would have been better, since LED2 is focusing
on cam itself, But if i think LED 1 is better.
On Dec 26, 7:03 pm, vishwas bhat <vishwas...@gmail.com> wrote:
> LED2 looks better to me
>
> On Sat, Dec 25, 2010 at 8:56 PM, BHAVANI PALAPARTHI <bpv...@gmail.com>wrote:
>
> > Guptaji,
>
> > Sorry for late response as I was more busy on solar!
>
> > I have anticipated this response either from you or somebody! Enclosed
> > please find 4photos taken from different angles of LED street light
> > installation wherein 2 brands LEDs have been used of same wattage.
>
> > Whether you believe it or not,when we asked feedback of a security
> > guard(thinking any one of us in the team may give biased feedback towards a
> > particular brand), we have got a perfect answer.
>
> > Now if you can tell us any one of our members in the forum can identify the
> > impressive luminary out of 2 in these 2photos, they can choose that brand
> > LEDs without any hesitation.
>
> > I will let you know all the brands after hearing responses from at least
> > 5members.If somebody is seriously interested, I can even take to the site
> > for first hand look to understand more about what light angle can make a
> > difference while choosing LED lighting!
>
> > Looks like solving a puzzle but its that worth who is seriously considering
> > LED lighting applications!
>
> > BHAVANI PALAPARTHI
>
> > On Tue, Dec 21, 2010 at 7:52 PM, KEPLSolarLEDs <gupt...@kwalityindia.com>wrote:
>
> >> Bhavani garu,
>
> >> Your ref: "it would be ideal to demand from LED at least 180deg light
> >> angle and currently *OSRAM is the only one company* giving this much
>
> >> Bhavani garu,
>
> >> Your ref: "it would be ideal to demand from LED at least 180deg light
> >> On Tue, Dec 21, 2010 at 3:17 PM, deepak kelkar <squaree...@gmail.com>wrote:
>
> >>> Actually I need more information on lumens and lux. this is same as kw
> >>> plant and kwh output. In reality it is lux that matters more than lumens.
> >>> Am I correct ?
>
> >>> Deepak Kelkar
>
> >>> On Tue, Dec 21, 2010 at 3:07 PM, KEPLSolarLEDs <
> >>> gupt...@kwalityindia.com> wrote:
>
> >>> Actually I need more information on lumens and lux. this is same as kw
> >>> plant and kwh output. In reality it is lux that matters more than lumens.
> >>> Am I correct ?
>
> >>> Deepak Kelkar
>
> >>> On Tue, Dec 21, 2010 at 3:07 PM, KEPLSolarLEDs <
>
> >>>> Today's LEDs like Kwality PolyWa LEDs Have *efficacy *of 100Lumens
Ram S
Dec 27, 2010, 12:35:36 AM12/27/10
to green...@googlegroups.com
Hi,
LED 2 looks brighter than 1.
Regards,
Ram ShirhattiRegards,
Ram Shirhatti
LED 2 looks brighter than 1.
Regards,
Ram Shirhatti
Ram Shirhatti
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