Author Topic: Cobra head without ballast  (Read 1795 times)
Keyless
Member
***
Offline

View Posts
View Gallery

Cobra head without ballast « on: October 27, 2018, 04:25:11 PM » Author: Keyless
Could a large buyer (like a DOT) or contractor order Cobra heads without the ballast, capacitor and igniter? If they would allow it, what do you think the cost per fixture would be vs what it is now? Still yet can someone like me order a Cobra without the ballast in that technically most orders are "custom" anyway?


My thinking is that with LED HID cobs being readily available, one could just buy the fixture and use cobs instead. If the LEDs or driver fail, replacing it is much simpler and cheaper (I would think). That and the fact I like the look of HID cobras vs the new LEDs lol. IMHO they look kind of ugly and I do not like their light distribution. And of course you could always but incandescents and SBMVs in them  :P  
« Last Edit: October 27, 2018, 04:26:53 PM by Keyless » Logged
Cole D.
Member
*****
Offline

View Posts
View Gallery

123 V 60 CPS


Dk944Mr-jX4jbnoUUj7xAw
Re: Cobra head without ballast « Reply #1 on: October 27, 2018, 05:20:50 PM » Author: Cole D.
I agree with you on that. I don't know why the LEDs have to be integrated into the fixture, I think it would be better just to replace the bulbs with LED and disable the ballast and ignitor on existing fixtures. I'm told it has to do with the efficiency of the LED optics and plus the LEDs work better if there is a heat sink, hence why the LED fixtures are so thin and have those ribbed areas on top of the unit.
Logged

Collect vintage incandescent and fluorescent fixtures. Also like HID lighting and streetlights.

Keyless
Member
***
Offline

View Posts
View Gallery

Re: Cobra head without ballast « Reply #2 on: October 27, 2018, 06:40:30 PM » Author: Keyless
Well said. I don't entirely by the heat sink theory manufacturers push, as LED filament bulbs (at least the good quality ones) do fine without them. Then again I admit to knowing they are low wattage often resistive or capacitive drivers- but still.
« Last Edit: October 27, 2018, 06:43:18 PM by Keyless » Logged
FGS
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Rory Mercury!


Re: Cobra head without ballast « Reply #3 on: October 27, 2018, 08:22:16 PM » Author: FGS
Well said. I don't entirely by the heat sink theory manufacturers push, as LED filament bulbs (at least the good quality ones) do fine without them. Then again I admit to knowing they are low wattage often resistive or capacitive drivers- but still.

You have a desktop computer (easier than a laptop) right? Open it up and remove the heat sink off the processor and see how long it lasts before overheating and shut down. The heat sink is designed to suck the heat away from the hot chip. The fins on them transfer the heat from them into the atmosphere.

Filament LEDs do have heat sinks. It’s not the familiar finned aluminum block. The gas fill inside the bulb acts like it. The gas take heat off the filaments and transfer it to the glass bulb which transfer it off to the atmosphere.
Logged

Why I like LEDs on top of other lighting tech?
LEDs = Upgrade 95% of the applications. (That is if you avoid eBay's LEDs).


LED brainwash? No, people uses them cuz they work well for them.

Keyless
Member
***
Offline

View Posts
View Gallery

Re: Cobra head without ballast « Reply #4 on: October 27, 2018, 09:21:59 PM » Author: Keyless
You have a desktop computer (easier than a laptop) right? Open it up and remove the heat sink off the processor and see how long it lasts before overheating and shut down. The heat sink is designed to suck the heat away from the hot chip. The fins on them transfer the heat from them into the atmosphere.

Filament LEDs do have heat sinks. It’s not the familiar finned aluminum block. The gas fill inside the bulb acts like it. The gas take heat off the filaments and transfer it to the glass bulb which transfer it off to the atmosphere.

Of course, which gets rid of the metal heat sink. Or in the case of cobs its part of the bulb.
Logged
joseph_125
Member
*****
Offline

Gender: Male
View Posts
View Gallery


GoL
Re: Cobra head without ballast « Reply #5 on: October 27, 2018, 10:20:24 PM » Author: joseph_125
Ballast-less cobraheads used to be a option available on the spec sheet but it seems most newer spec sheets don't list that option but I guess you might be able to request it.

Back then the reason for ordering a empty cobrahead was usually as a spot replacement for a damaged remote ballasted mercury fixture or rarely to use as a incandescent cobrahead. 
Logged
mdcastle
Member
***
Offline

View Posts
View Gallery

mdcastle 26956281@N02
WWW
Re: Cobra head without ballast « Reply #6 on: October 27, 2018, 11:58:39 PM » Author: mdcastle
A lot of the efficiency of LED streetlights comes from custom designing the optics for LEDs. A Corncob equipped cobrahead would make no sense since you're trying to convert a directional light source (an LED) into an omnidirectional light source by having emitters firing in all directions, then using the optics in the fixture to convert it back into a directional source, and the optics are designed for lamps that are a lot more compact then corncob LEDS.
Logged
Fluorescent05
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Zack


Re: Cobra head without ballast « Reply #7 on: October 30, 2018, 08:24:27 PM » Author: Fluorescent05
You have a desktop computer (easier than a laptop) right? Open it up and remove the heat sink off the processor and see how long it lasts before overheating and shut down. The heat sink is designed to suck the heat away from the hot chip. The fins on them transfer the heat from them into the atmosphere.

Filament LEDs do have heat sinks. It’s not the familiar finned aluminum block. The gas fill inside the bulb acts like it. The gas take heat off the filaments and transfer it to the glass bulb which transfer it off to the atmosphere.
I have done just that experiment with an old desktop and a Pentium 4 processor. It lasted about 5 seconds at most without overheating and turning off.
Logged

I can't pretend a stranger is a long awaited friend. -Neil Peart

wide-lite 1000
Member
*****
Offline

Gender: Male
View Posts
View Gallery


Re: Cobra head without ballast « Reply #8 on: October 30, 2018, 11:42:09 PM » Author: wide-lite 1000
the local chinese resturant by me converted all their parking lot lights (m-400s,itt-25's and shoe boxes) with cob-led's and unless you look closely you can't really tell the difference,
color-wise they look like mh .this was done 2 years ago and so far NONE have failed operating dusk to dawn every night
Logged

Collector,Hoarder,Pack-rat! Clear mercury Rules!!

Print 
© 2005-2024 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies