Sharp Introduces Nine New LED Lamps for Home Use

Phillips makes them. I have seen them at Home Depot.

Tom

 

Thanks Tom, I will take a look,

Icarus

 

A lot of the track light fixtures are stepped down to 12v and incorporate rheostats. I have yet to find ANY track light LED's that are dimmable, but I'd love to hear of a source. The Home Depot Par 38's put out the equivalent brightness of a 25 watt incandescent, and the beam is about 50% narrower than a regular par. Same with the Walmart jobbies ... well ... maybe they're a bit brighter. Maybe next year .... who knows.

.

 

LEDs don't work well with standard dimmers. This is because LEDs require a minimum voltage to operate, while standard dimmers do phase conduction control on a sine wave, which means that the voltage is too low for most of the dimming range. You end up with "off, off, still off, FULL ON!"

For LEDs you want PWM (Pulse Width Modulation) dimmers. A PWM dimmer always uses full voltage, but varies the ration of on to off time (the pulse width). Any of the standard 12V LED lamps will work with PWM dimming. The packaging says that they won't work with dimmers, but that's for standard dimmers. Replace your 12V transformer with a 12V PWM unit and they will work fine. I have two of the Phillips units running as a test right now.

Tom

 

I went to my local HD today (aka "the evil empire!) and asked the friendly sales guy if they had any LED bulbs. "NO". was all he said. Walking down the aisle, I found the LED bulbs. Of course they didn't have anything other than candellabras, and Par bulbs. No conventional bulbs.

The price is coming down quite quickly however.

 

I just despair about the build quality-control issues where they'll
inevitably be made in quantity as the prices drop.
.
_H*

 

Look at the (lack of) quality with LED Christmas lights.

Tom

 

On the other hand, QC has come a long way with CFLs. Remember the day when they were ~$20. Now they are $.99 for a 4 pack. If LEDs come down the same way, even if the defect rate is near that of CFls then they will gain acceptance.

 

I certainly do remember. I bought a bunch of the early ones for our shop, and they failed very quickly. That put me off CFLs for a long time. Now they seem to work very well, and I happily use them in many of our fixtures.

About two years ago I swapped out the cabin lighting in our boat with LED modules. The power savings makes a huge difference when you are running on battery power.

Tom

 

there's a ton of them on EvilBay

 

What do the PWM's run, cost wise? Are they more bulky? or are they small enough to fit with existing fixtures.

.

 

Yikes, that'd be a bit over $40 a piece U.S. after sales tax ... are you satisfied with the amount of brightness ... being equivalent to 40 watts incandescent ? How wide an angle does the light spread. I'm finding under 33° to be pretty typical ... which is kind of narrow.

 

The reality is the price needs to drop to ~$10 to begin to make major inroads. Even us off gridders who pinch every lumen out of every kwh aren't going to give away $40 to to save 10 watts. For us it is ten times more cost effective than those of you on grid.

Pretty tough to pay back the 10 watts if you are only paying $.10-.15 kwh. By the time the LEDs are dead, the price should be near zero. Unfortunately the early adopters pay the price.

 

I bought a couple of LED light bulbs ~10 years ago. At that time, they were ~6 leds in a glass bulb, assemble nearly by hand as a cottage industry. I got them in 120vac and 12vdc versions. I bought them as beta units, and they really didn't serve much purpose as they put out suc tiny amounts of light.

Still use them, one as a outside light on the porch to sweep the snow off, and the other in a mud room on the 12vdc wiring in the off grid house.

 

Do Led's suffer from cold start issues like sfls? At-30 my cfls take a long time to fire.

 

A 5 watt LED at $.15kw will burn ~200 hours, or ~1300 hours for ~$1. At 4 hours a day it would take just about a year to burn $1 worth of electricity. (assuming my math is any where near right!) So replacing a $1 cfl (~15watt)with a $10 LED of similar lumen to save 75% of the power net/net would take ~15 years (give or take) to pay off. Compare that to how quickly it pays off with a 60 watt incandescent bulb, at say a $.50 cost. Instead of 15 years, it would take ~ 1.5 years. So, one can see that getting below the $10 threshold is essential.

(Assuming energy prices go up over the life of a LED, the savings come sooner of course)

 

They shouldn't, unless there is something in the drive circuit I don't know about. There is no arc to fire up.

In my experience in other applications, LEDs get brighter at cold junction temperatures and constant current. But Vf also increases, and depending in the particular drive circuit, this could cause the current (and therefore light output) to decrease.

 

Fuzzy,

Thanks, I confess I know less than nothing about LED lighting. Like I said, I hope the price falls >$10 for conventional looking bulbs soon. In our off grid house, lighting is the major loads, so cutting our lighting loads down by ~75% will be huge.